/*
 * QuickJS C library
 * 
 * Copyright (c) 2017-2019 Fabrice Bellard
 * Copyright (c) 2017-2019 Charlie Gordon
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
#include <stdlib.h>
#include <stdio.h>
#include <stdarg.h>
#include <inttypes.h>
#include <string.h>
#include <assert.h>
#include <unistd.h>
#include <errno.h>
#include <fcntl.h>
#include <sys/time.h>
#include <time.h>
#include <signal.h>
#if defined(_WIN32)
#include <windows.h>
#include <conio.h>
#else
#include <dlfcn.h>
#include <termios.h>
#include <sys/ioctl.h>
#if defined(__APPLE__)
typedef sig_t sighandler_t;
#endif
#endif

#include "cutils.h"
#include "list.h"
#include "quickjs-libc.h"

static void js_std_dbuf_init(JSContext *ctx, DynBuf *s)
{
    dbuf_init2(s, JS_GetRuntime(ctx), (DynBufReallocFunc *)js_realloc_rt);
}

/* TODO:
   - add exec() wrapper
   - add minimal VT100 emulation for win32
   - add socket calls
*/

typedef struct {
    struct list_head link;
    int fd;
    JSValue rw_func[2];
} JSOSRWHandler;

typedef struct {
    struct list_head link;
    int sig_num;
    JSValue func;
} JSOSSignalHandler;

typedef struct {
    struct list_head link;
    BOOL has_object;
    int64_t timeout;
    JSValue func;
} JSOSTimer;

/* initialize the lists so js_std_free_handlers() can always be called */
static struct list_head os_rw_handlers = LIST_HEAD_INIT(os_rw_handlers);
static struct list_head os_signal_handlers = LIST_HEAD_INIT(os_signal_handlers);
static struct list_head os_timers = LIST_HEAD_INIT(os_timers);
static uint64_t os_pending_signals;
static int eval_script_recurse;
static int (*os_poll_func)(JSContext *ctx);

static JSValue js_printf_internal(JSContext *ctx,
                                  int argc, JSValueConst *argv, FILE *fp)
{
    char fmtbuf[32];
    uint8_t cbuf[UTF8_CHAR_LEN_MAX+1];
    JSValue res;
    DynBuf dbuf;
    const char *fmt_str;
    const uint8_t *fmt, *fmt_end;
    const uint8_t *p;
    char *q;
    int i, c, len;
    int32_t int32_arg;
    int64_t int64_arg;
    double double_arg;
    const char *string_arg;
    enum { PART_FLAGS, PART_WIDTH, PART_DOT, PART_PREC, PART_MODIFIER } part;
    int modsize;
    /* Use indirect call to dbuf_printf to prevent gcc warning */
    int (*dbuf_printf_fun)(DynBuf *s, const char *fmt, ...) = (void*)dbuf_printf;

    js_std_dbuf_init(ctx, &dbuf);

    if (argc > 0) {
        fmt_str = JS_ToCStringLen(ctx, &len, argv[0], FALSE);
        if (!fmt_str)
            goto fail;

        i = 1;
        fmt = (const uint8_t *)fmt_str;
        fmt_end = fmt + len;
        while (fmt < fmt_end) {
            for (p = fmt; fmt < fmt_end && *fmt != '%'; fmt++)
                continue;
            dbuf_put(&dbuf, p, fmt - p);
            if (fmt >= fmt_end)
                break;
            q = fmtbuf;
            *q++ = *fmt++;  /* copy '%' */
            part = PART_FLAGS;
            modsize = 0;
            for (;;) {
                if (q >= fmtbuf + sizeof(fmtbuf) - 1)
                    goto invalid;

                c = *fmt++;
                *q++ = c;
                *q = '\0';

                switch (c) {
                case '1': case '2': case '3':
                case '4': case '5': case '6':
                case '7': case '8': case '9':
                    if (part != PART_PREC) {
                        if (part <= PART_WIDTH)
                            part = PART_WIDTH;
                        else 
                            goto invalid;
                    }
                    continue;

                case '0': case '#': case '+': case '-': case ' ': case '\'':
                    if (part > PART_FLAGS)
                        goto invalid;
                    continue;

                case '.':
                    if (part > PART_DOT)
                        goto invalid;
                    part = PART_DOT;
                    continue;

                case '*':
                    if (part < PART_WIDTH)
                        part = PART_DOT;
                    else if (part == PART_DOT)
                        part = PART_MODIFIER;
                    else
                        goto invalid;

                    if (i >= argc)
                        goto missing;

                    if (JS_ToInt32(ctx, &int32_arg, argv[i++]))
                        goto fail;
                    q += snprintf(q, fmtbuf + sizeof(fmtbuf) - q, "%d", int32_arg);
                    continue;

                case 'h':
                    if (modsize != 0 && modsize != -1)
                        goto invalid;
                    modsize--;
                    part = PART_MODIFIER;
                    continue;
                case 'l':
                    q--;
                    if (modsize != 0 && modsize != 1)
                        goto invalid;
                    modsize++;
                    part = PART_MODIFIER;
                    continue;

                case 'c':
                    if (i >= argc)
                        goto missing;
                    if (JS_IsString(argv[i])) {
                        string_arg = JS_ToCString(ctx, argv[i++]);
                        if (!string_arg)
                            goto fail;
                        int32_arg = unicode_from_utf8((uint8_t *)string_arg, UTF8_CHAR_LEN_MAX, &p);
                        JS_FreeCString(ctx, string_arg);
                    } else {
                        if (JS_ToInt32(ctx, &int32_arg, argv[i++]))
                            goto fail;
                    }
                    /* handle utf-8 encoding explicitly */
                    if ((unsigned)int32_arg > 0x10FFFF)
                        int32_arg = 0xFFFD;
                    /* ignore conversion flags, width and precision */
                    len = unicode_to_utf8(cbuf, int32_arg);
                    dbuf_put(&dbuf, cbuf, len);
                    break;

                case 'd':
                case 'i':
                case 'o':
                case 'u':
                case 'x':
                case 'X':
                    if (i >= argc)
                        goto missing;
                    if (modsize > 0) {
                        if (JS_ToInt64(ctx, &int64_arg, argv[i++]))
                            goto fail;
                        q[1] = q[-1];
                        q[-1] = q[0] = 'l';
                        q[2] = '\0';
                        dbuf_printf_fun(&dbuf, fmtbuf, (long long)int64_arg);
                    } else {
                        if (JS_ToInt32(ctx, &int32_arg, argv[i++]))
                            goto fail;
                        dbuf_printf_fun(&dbuf, fmtbuf, int32_arg);
                    }
                    break;

                case 's':
                    if (i >= argc)
                        goto missing;
                    string_arg = JS_ToCString(ctx, argv[i++]);
                    if (!string_arg)
                        goto fail;
                    dbuf_printf_fun(&dbuf, fmtbuf, string_arg);
                    JS_FreeCString(ctx, string_arg);
                    break;

                case 'e':
                case 'f':
                case 'g':
                case 'a':
                case 'E':
                case 'F':
                case 'G':
                case 'A':
                    if (i >= argc)
                        goto missing;
                    if (JS_ToFloat64(ctx, &double_arg, argv[i++]))
                        goto fail;
                    dbuf_printf_fun(&dbuf, fmtbuf, double_arg);
                    break;

                case '%':
                    dbuf_putc(&dbuf, '%');
                    break;

                default:
                    /* XXX: should support an extension mechanism */
                invalid:
                    JS_ThrowTypeError(ctx, "invalid conversion specifier in format string");
                    goto fail;
                missing:
                    JS_ThrowReferenceError(ctx, "missing argument for conversion specifier");
                    goto fail;
                }
                break;
            }
        }
        JS_FreeCString(ctx, fmt_str);
    }
    if (dbuf.error) {
        res = JS_ThrowOutOfMemory(ctx);
    } else {
        if (fp) {
            len = fwrite(dbuf.buf, 1, dbuf.size, fp);
            res = JS_NewInt32(ctx, len);
        } else {
            res = JS_NewStringLen(ctx, (char *)dbuf.buf, dbuf.size);
        }
    }
    dbuf_free(&dbuf);
    return res;

fail:
    dbuf_free(&dbuf);
    return JS_EXCEPTION;
}

uint8_t *js_load_file(JSContext *ctx, size_t *pbuf_len, const char *filename)
{
    FILE *f;
    uint8_t *buf;
    size_t buf_len;

    f = fopen(filename, "rb");
    if (!f)
        return NULL;
    fseek(f, 0, SEEK_END);
    buf_len = ftell(f);
    fseek(f, 0, SEEK_SET);
    if (ctx)
        buf = js_malloc(ctx, buf_len + 1);
    else
        buf = malloc(buf_len + 1);
    fread(buf, 1, buf_len, f);
    buf[buf_len] = '\0';
    fclose(f);
    *pbuf_len = buf_len;
    return buf;
}

/* load and evaluate a file */
static JSValue js_loadScript(JSContext *ctx, JSValueConst this_val,
                             int argc, JSValueConst *argv)
{
    uint8_t *buf;
    const char *filename;
    JSValue ret;
    size_t buf_len;
    
    filename = JS_ToCString(ctx, argv[0]);
    if (!filename)
        return JS_EXCEPTION;
    buf = js_load_file(ctx, &buf_len, filename);
    if (!buf) {
        JS_ThrowReferenceError(ctx, "could not load '%s'", filename);
        JS_FreeCString(ctx, filename);
        return JS_EXCEPTION;
    }
    ret = JS_Eval(ctx, (char *)buf, buf_len, filename,
                  JS_EVAL_TYPE_GLOBAL | JS_EVAL_FLAG_SHEBANG);
    js_free(ctx, buf);
    JS_FreeCString(ctx, filename);
    return ret;
}

typedef JSModuleDef *(JSInitModuleFunc)(JSContext *ctx,
                                        const char *module_name);


#if defined(_WIN32)
static JSModuleDef *js_module_loader_so(JSContext *ctx,
                                        const char *module_name)
{
    JS_ThrowReferenceError(ctx, "shared library modules are not supported yet");
    return NULL;
}
#else
static JSModuleDef *js_module_loader_so(JSContext *ctx,
                                        const char *module_name)
{
    JSModuleDef *m;
    void *hd;
    JSInitModuleFunc *init;
    char *filename;
    
    if (!strchr(module_name, '/')) {
        /* must add a '/' so that the DLL is not searched in the
           system library paths */
        filename = js_malloc(ctx, strlen(module_name) + 2 + 1);
        if (!filename)
            return NULL;
        strcpy(filename, "./");
        strcpy(filename + 2, module_name);
    } else {
        filename = (char *)module_name;
    }
    
    /* C module */
    hd = dlopen(filename, RTLD_NOW | RTLD_LOCAL);
    if (filename != module_name)
        js_free(ctx, filename);
    if (!hd) {
        JS_ThrowReferenceError(ctx, "could not load module filename '%s' as shared library",
                               module_name);
        goto fail;
    }

    init = dlsym(hd, "js_init_module");
    if (!init) {
        JS_ThrowReferenceError(ctx, "could not load module filename '%s': js_init_module not found",
                               module_name);
        goto fail;
    }

    m = init(ctx, module_name);
    if (!m) {
        JS_ThrowReferenceError(ctx, "could not load module filename '%s': initialization error",
                               module_name);
    fail:
        if (hd)
            dlclose(hd);
        return NULL;
    }
    return m;
}
#endif /* !_WIN32 */

JSModuleDef *js_module_loader(JSContext *ctx,
                              const char *module_name, void *opaque)
{
    JSModuleDef *m;

    if (has_suffix(module_name, ".so")) {
        m = js_module_loader_so(ctx, module_name);
    } else {
        size_t buf_len;
        uint8_t *buf;
        JSValue func_val;
    
        buf = js_load_file(ctx, &buf_len, module_name);
        if (!buf) {
            JS_ThrowReferenceError(ctx, "could not load module filename '%s'",
                                   module_name);
            return NULL;
        }
        
        /* compile the module */
        func_val = JS_Eval(ctx, (char *)buf, buf_len, module_name,
                           JS_EVAL_TYPE_MODULE | JS_EVAL_FLAG_COMPILE_ONLY);
        js_free(ctx, buf);
        if (JS_IsException(func_val))
            return NULL;
        /* the module is already referenced, so we must free it */
        m = JS_VALUE_GET_PTR(func_val);
        JS_FreeValue(ctx, func_val);
    }
    return m;
}

static JSValue js_std_exit(JSContext *ctx, JSValueConst this_val,
                           int argc, JSValueConst *argv)
{
    int status;
    if (JS_ToInt32(ctx, &status, argv[0]))
        status = -1;
    exit(status);
    return JS_UNDEFINED;
}

static JSValue js_std_getenv(JSContext *ctx, JSValueConst this_val,
                           int argc, JSValueConst *argv)
{
    const char *name, *str;
    name = JS_ToCString(ctx, argv[0]);
    if (!name)
        return JS_EXCEPTION;
    str = getenv(name);
    JS_FreeCString(ctx, name);
    if (!str)
        return JS_UNDEFINED;
    else
        return JS_NewString(ctx, str);
}

static JSValue js_std_gc(JSContext *ctx, JSValueConst this_val,
                         int argc, JSValueConst *argv)
{
    JS_RunGC(JS_GetRuntime(ctx));
    return JS_UNDEFINED;
}

static int interrupt_handler(JSRuntime *rt, void *opaque)
{
    return (os_pending_signals >> SIGINT) & 1;
}

static JSValue js_evalScript(JSContext *ctx, JSValueConst this_val,
                             int argc, JSValueConst *argv)
{
    const char *str;
    int len;
    JSValue ret;
    str = JS_ToCStringLen(ctx, &len, argv[0], FALSE);
    if (!str)
        return JS_EXCEPTION;
    if (++eval_script_recurse == 1) {
        /* install the interrupt handler */
        JS_SetInterruptHandler(JS_GetRuntime(ctx), interrupt_handler, NULL);
    }
    ret = JS_Eval(ctx, str, len, "<evalScript>", JS_EVAL_TYPE_GLOBAL);
    if (--eval_script_recurse == 0) {
        /* remove the interrupt handler */
        JS_SetInterruptHandler(JS_GetRuntime(ctx), NULL, NULL);
        os_pending_signals &= ~((uint64_t)1 << SIGINT);
        /* convert the uncatchable "interrupted" error into a normal error
           so that it can be caught by the REPL */
        if (JS_IsException(ret))
            JS_ResetUncatchableError(ctx);
    }
    return ret;
}

static JSClassID js_std_file_class_id;

typedef struct {
    FILE *f;
    BOOL close_in_finalizer;
} JSSTDFile;

static void js_std_file_finalizer(JSRuntime *rt, JSValue val)
{
    JSSTDFile *s = JS_GetOpaque(val, js_std_file_class_id);
    if (s) {
        if (s->f && s->close_in_finalizer)
            fclose(s->f);
        js_free_rt(rt, s);
    }
}

static JSValue js_new_std_error(JSContext *ctx, int err)
{
    JSValue obj;
    /* XXX: could add a specific Error prototype */
    obj = JS_NewError(ctx);
    JS_DefinePropertyValueStr(ctx, obj, "message",
                              JS_NewString(ctx, strerror(err)),
                              JS_PROP_WRITABLE | JS_PROP_CONFIGURABLE);
    JS_DefinePropertyValueStr(ctx, obj, "errno",
                              JS_NewInt32(ctx, err),
                              JS_PROP_WRITABLE | JS_PROP_CONFIGURABLE);
    return obj;
}

static JSValue js_std_error_constructor(JSContext *ctx, JSValueConst new_target,
                                        int argc, JSValueConst *argv)
{
    int err;
    if (JS_ToInt32(ctx, &err, argv[0]))
        return JS_EXCEPTION;
    return js_new_std_error(ctx, err);
}

static JSValue js_std_error_strerror(JSContext *ctx, JSValueConst this_val,
                                     int argc, JSValueConst *argv)
{
    int err;
    if (JS_ToInt32(ctx, &err, argv[0]))
        return JS_EXCEPTION;
    return JS_NewString(ctx, strerror(err));
}

static JSValue js_std_throw_errno(JSContext *ctx, int err)
{
    JSValue obj;
    obj = js_new_std_error(ctx, err);
    if (JS_IsException(obj))
        obj = JS_NULL;
    return JS_Throw(ctx, obj);
}

static JSValue js_new_std_file(JSContext *ctx, FILE *f, BOOL close_in_finalizer)
{
    JSSTDFile *s;
    JSValue obj;
    obj = JS_NewObjectClass(ctx, js_std_file_class_id);
    if (JS_IsException(obj))
        return obj;
    s = js_mallocz(ctx, sizeof(*s));
    if (!s) {
        JS_FreeValue(ctx, obj);
        return JS_EXCEPTION;
    }
    s->close_in_finalizer = close_in_finalizer;
    s->f = f;
    JS_SetOpaque(obj, s);
    return obj;
}

static JSValue js_std_open(JSContext *ctx, JSValueConst this_val,
                           int argc, JSValueConst *argv)
{
    const char *filename, *mode = NULL;
    FILE *f;

    filename = JS_ToCString(ctx, argv[0]);
    if (!filename)
        goto fail;
    mode = JS_ToCString(ctx, argv[1]);
    if (!mode)
        goto fail;
    if (mode[strspn(mode, "rwa+b")] != '\0') {
        js_std_throw_errno(ctx, EINVAL);
        goto fail;
    }

    f = fopen(filename, mode);
    JS_FreeCString(ctx, filename);
    JS_FreeCString(ctx, mode);
    if (!f)
        return js_std_throw_errno(ctx, errno);
    return js_new_std_file(ctx, f, TRUE);
 fail:
    JS_FreeCString(ctx, filename);
    JS_FreeCString(ctx, mode);
    return JS_EXCEPTION;
}

static JSValue js_std_tmpfile(JSContext *ctx, JSValueConst this_val,
                              int argc, JSValueConst *argv)
{
    FILE *f;
    f = tmpfile();
    if (!f)
        return js_std_throw_errno(ctx, errno);
    return js_new_std_file(ctx, f, TRUE);
}

static JSValue js_std_sprintf(JSContext *ctx, JSValueConst this_val,
                          int argc, JSValueConst *argv)
{
    return js_printf_internal(ctx, argc, argv, NULL);
}

static JSValue js_std_printf(JSContext *ctx, JSValueConst this_val,
                             int argc, JSValueConst *argv)
{
    return js_printf_internal(ctx, argc, argv, stdout);
}

static FILE *js_std_file_get(JSContext *ctx, JSValueConst obj)
{
    JSSTDFile *s = JS_GetOpaque2(ctx, obj, js_std_file_class_id);
    if (!s)
        return NULL;
    if (!s->f) {
        js_std_throw_errno(ctx, EBADF);
        return NULL;
    }
    return s->f;
}

static JSValue js_std_file_puts(JSContext *ctx, JSValueConst this_val,
                                int argc, JSValueConst *argv, int magic)
{
    FILE *f;
    int i;
    const char *str;

    if (magic == 0) {
        f = stdout;
    } else {
        f = js_std_file_get(ctx, this_val);
        if (!f)
            return JS_EXCEPTION;
    }
    
    for(i = 0; i < argc; i++) {
        str = JS_ToCString(ctx, argv[i]);
        if (!str)
            return JS_EXCEPTION;
        fputs(str, f);
        JS_FreeCString(ctx, str);
    }
    return JS_UNDEFINED;
}

static JSValue js_std_file_close(JSContext *ctx, JSValueConst this_val,
                                 int argc, JSValueConst *argv)
{
    JSSTDFile *s = JS_GetOpaque2(ctx, this_val, js_std_file_class_id);
    if (!s)
        return JS_EXCEPTION;
    if (!s->f)
        return js_std_throw_errno(ctx, EBADF);
    fclose(s->f);
    s->f = NULL;
    return JS_UNDEFINED;
}

static JSValue js_std_file_printf(JSContext *ctx, JSValueConst this_val,
                                  int argc, JSValueConst *argv)
{
    FILE *f = js_std_file_get(ctx, this_val);
    if (!f)
        return JS_EXCEPTION;
    return js_printf_internal(ctx, argc, argv, f);
}

static JSValue js_std_file_flush(JSContext *ctx, JSValueConst this_val,
                                 int argc, JSValueConst *argv)
{
    FILE *f = js_std_file_get(ctx, this_val);
    if (!f)
        return JS_EXCEPTION;
    fflush(f);
    return JS_UNDEFINED;
}

static JSValue js_std_file_tell(JSContext *ctx, JSValueConst this_val,
                                int argc, JSValueConst *argv)
{
    FILE *f = js_std_file_get(ctx, this_val);
    int64_t pos;
    if (!f)
        return JS_EXCEPTION;
#if defined(__linux__)
    pos = ftello(f);
#else
    pos = ftell(f);
#endif
    return JS_NewInt64(ctx, pos);
}

static JSValue js_std_file_seek(JSContext *ctx, JSValueConst this_val,
                                int argc, JSValueConst *argv)
{
    FILE *f = js_std_file_get(ctx, this_val);
    int64_t pos;
    int whence, ret;
    if (!f)
        return JS_EXCEPTION;
    if (JS_ToInt64(ctx, &pos, argv[0]))
        return JS_EXCEPTION;
    if (JS_ToInt32(ctx, &whence, argv[1]))
        return JS_EXCEPTION;
#if defined(__linux__)
    ret = fseeko(f, pos, whence);
#else
    ret = fseek(f, pos, whence);
#endif
    if (ret < 0)
        return js_std_throw_errno(ctx, EBADF);
    return JS_UNDEFINED;
}

static JSValue js_std_file_eof(JSContext *ctx, JSValueConst this_val,
                               int argc, JSValueConst *argv)
{
    FILE *f = js_std_file_get(ctx, this_val);
    if (!f)
        return JS_EXCEPTION;
    return JS_NewBool(ctx, feof(f));
}

static JSValue js_std_file_fileno(JSContext *ctx, JSValueConst this_val,
                                  int argc, JSValueConst *argv)
{
    FILE *f = js_std_file_get(ctx, this_val);
    if (!f)
        return JS_EXCEPTION;
    return JS_NewInt32(ctx, fileno(f));
}

static JSValue js_std_file_read_write(JSContext *ctx, JSValueConst this_val,
                                      int argc, JSValueConst *argv, int magic)
{
    FILE *f = js_std_file_get(ctx, this_val);
    uint64_t pos, len;
    size_t size, ret;
    uint8_t *buf;
    
    if (!f)
        return JS_EXCEPTION;
    if (JS_ToIndex(ctx, &pos, argv[1]))
        return JS_EXCEPTION;
    if (JS_ToIndex(ctx, &len, argv[2]))
        return JS_EXCEPTION;
    buf = JS_GetArrayBuffer(ctx, &size, argv[0]);
    if (!buf)
        return JS_EXCEPTION;
    if (pos + len > size)
        return JS_ThrowRangeError(ctx, "read/write array buffer overflow");
    if (magic)
        ret = fwrite(buf + pos, 1, len, f);
    else
        ret = fread(buf + pos, 1, len, f);
    return JS_NewInt64(ctx, ret);
}

/* XXX: could use less memory and go faster */
static JSValue js_std_file_getline(JSContext *ctx, JSValueConst this_val,
                                   int argc, JSValueConst *argv)
{
    FILE *f = js_std_file_get(ctx, this_val);
    int c;
    DynBuf dbuf;
    JSValue obj;
    
    if (!f)
        return JS_EXCEPTION;

    js_std_dbuf_init(ctx, &dbuf);
    for(;;) {
        c = fgetc(f);
        if (c == EOF) {
            if (dbuf.size == 0) {
                /* EOF */
                dbuf_free(&dbuf);
                return JS_NULL;
            } else {
                break;
            }
        }
        if (c == '\n')
            break;
        if (dbuf_putc(&dbuf, c)) {
            dbuf_free(&dbuf);
            return JS_ThrowOutOfMemory(ctx);
        }
    }
    obj = JS_NewStringLen(ctx, (const char *)dbuf.buf, dbuf.size);
    dbuf_free(&dbuf);
    return obj;
}

/* XXX: could use less memory and go faster */
static JSValue js_std_file_readAsString(JSContext *ctx, JSValueConst this_val,
                                        int argc, JSValueConst *argv)
{
    FILE *f = js_std_file_get(ctx, this_val);
    int c;
    DynBuf dbuf;
    JSValue obj;
    uint64_t max_size64;
    size_t max_size;
    JSValueConst max_size_val;
    
    if (!f)
        return JS_EXCEPTION;

    if (argc >= 1)
        max_size_val = argv[0];
    else
        max_size_val = JS_UNDEFINED;
    max_size = (size_t)-1;
    if (!JS_IsUndefined(max_size_val)) {
        if (JS_ToIndex(ctx, &max_size64, max_size_val))
            return JS_EXCEPTION;
        if (max_size64 < max_size)
            max_size = max_size64;
    }

    js_std_dbuf_init(ctx, &dbuf);
    while (max_size != 0) {
        c = fgetc(f);
        if (c == EOF)
            break;
        if (dbuf_putc(&dbuf, c)) {
            dbuf_free(&dbuf);
            return JS_EXCEPTION;
        }
        max_size--;
    }
    obj = JS_NewStringLen(ctx, (const char *)dbuf.buf, dbuf.size);
    dbuf_free(&dbuf);
    return obj;
}

static JSValue js_std_file_getByte(JSContext *ctx, JSValueConst this_val,
                                   int argc, JSValueConst *argv)
{
    FILE *f = js_std_file_get(ctx, this_val);
    if (!f)
        return JS_EXCEPTION;
    return JS_NewInt32(ctx, fgetc(f));
}

static JSValue js_std_file_putByte(JSContext *ctx, JSValueConst this_val,
                                   int argc, JSValueConst *argv)
{
    FILE *f = js_std_file_get(ctx, this_val);
    int c;
    if (!f)
        return JS_EXCEPTION;
    if (JS_ToInt32(ctx, &c, argv[0]))
        return JS_EXCEPTION;
    c = fputc(c, f);
    return JS_NewInt32(ctx, c);
}

static JSClassDef js_std_file_class = {
    "FILE",
    .finalizer = js_std_file_finalizer,
}; 

static const JSCFunctionListEntry js_std_funcs[] = {
    JS_CFUNC_DEF("exit", 1, js_std_exit ),
    JS_CFUNC_DEF("gc", 0, js_std_gc ),
    JS_CFUNC_DEF("evalScript", 1, js_evalScript ),
    JS_CFUNC_DEF("loadScript", 1, js_loadScript ),
    JS_CFUNC_DEF("getenv", 1, js_std_getenv ),

    /* FILE I/O */
    JS_CFUNC_DEF("open", 2, js_std_open ),
    JS_CFUNC_DEF("tmpfile", 0, js_std_tmpfile ),
    JS_CFUNC_MAGIC_DEF("puts", 1, js_std_file_puts, 0 ),
    JS_CFUNC_DEF("printf", 1, js_std_printf ),
    JS_CFUNC_DEF("sprintf", 1, js_std_sprintf ),
    JS_PROP_INT32_DEF("SEEK_SET", SEEK_SET, JS_PROP_CONFIGURABLE ),
    JS_PROP_INT32_DEF("SEEK_CUR", SEEK_CUR, JS_PROP_CONFIGURABLE ),
    JS_PROP_INT32_DEF("SEEK_END", SEEK_END, JS_PROP_CONFIGURABLE ),

    /* setenv, ... */
};

static const JSCFunctionListEntry js_std_error_funcs[] = {
    JS_CFUNC_DEF("strerror", 1, js_std_error_strerror ),
    /* various errno values */
#define DEF(x) JS_PROP_INT32_DEF(#x, x, JS_PROP_CONFIGURABLE )
    DEF(EINVAL),
    DEF(EIO),
    DEF(EACCES),
    DEF(EEXIST),
    DEF(ENOSPC),
    DEF(ENOSYS),
    DEF(EBUSY),
    DEF(ENOENT),
    DEF(EPERM),
    DEF(EPIPE),
    DEF(EBADF),
#undef DEF
};

static const JSCFunctionListEntry js_std_file_proto_funcs[] = {
    JS_CFUNC_DEF("close", 0, js_std_file_close ),
    JS_CFUNC_MAGIC_DEF("puts", 1, js_std_file_puts, 1 ),
    JS_CFUNC_DEF("printf", 1, js_std_file_printf ),
    JS_CFUNC_DEF("flush", 0, js_std_file_flush ),
    JS_CFUNC_DEF("tell", 0, js_std_file_tell ),
    JS_CFUNC_DEF("seek", 2, js_std_file_seek ),
    JS_CFUNC_DEF("eof", 0, js_std_file_eof ),
    JS_CFUNC_DEF("fileno", 0, js_std_file_fileno ),
    JS_CFUNC_MAGIC_DEF("read", 3, js_std_file_read_write, 0 ),
    JS_CFUNC_MAGIC_DEF("write", 3, js_std_file_read_write, 1 ),
    JS_CFUNC_DEF("getline", 0, js_std_file_getline ),
    JS_CFUNC_DEF("readAsString", 0, js_std_file_readAsString ),
    JS_CFUNC_DEF("getByte", 0, js_std_file_getByte ),
    JS_CFUNC_DEF("putByte", 1, js_std_file_putByte ),
    /* setvbuf, ferror, clearerr, ...  */
};

static int js_std_init(JSContext *ctx, JSModuleDef *m)
{
    JSValue proto, obj;
    
    /* FILE class */
    /* the class ID is created once */
    JS_NewClassID(&js_std_file_class_id);
    /* the class is created once per runtime */
    JS_NewClass(JS_GetRuntime(ctx), js_std_file_class_id, &js_std_file_class);
    proto = JS_NewObject(ctx);
    JS_SetPropertyFunctionList(ctx, proto, js_std_file_proto_funcs,
                               countof(js_std_file_proto_funcs));
    JS_SetClassProto(ctx, js_std_file_class_id, proto);

    JS_SetModuleExportList(ctx, m, js_std_funcs,
                           countof(js_std_funcs));
    JS_SetModuleExport(ctx, m, "in", js_new_std_file(ctx, stdin, FALSE));
    JS_SetModuleExport(ctx, m, "out", js_new_std_file(ctx, stdout, FALSE));
    JS_SetModuleExport(ctx, m, "err", js_new_std_file(ctx, stderr, FALSE));
    
    obj = JS_NewCFunction2(ctx, js_std_error_constructor,
                           "Error", 1, JS_CFUNC_constructor, 0);
    JS_SetPropertyFunctionList(ctx, obj, js_std_error_funcs,
                               countof(js_std_error_funcs));
    JS_SetModuleExport(ctx, m, "Error", obj);

    /* global object */
    JS_SetModuleExport(ctx, m, "global", JS_GetGlobalObject(ctx));
    return 0;
}

JSModuleDef *js_init_module_std(JSContext *ctx, const char *module_name)
{
    JSModuleDef *m;
    m = JS_NewCModule(ctx, module_name, js_std_init);
    if (!m)
        return NULL;
    JS_AddModuleExportList(ctx, m, js_std_funcs, countof(js_std_funcs));
    JS_AddModuleExport(ctx, m, "in");
    JS_AddModuleExport(ctx, m, "out");
    JS_AddModuleExport(ctx, m, "err");
    JS_AddModuleExport(ctx, m, "global");
    JS_AddModuleExport(ctx, m, "Error");
    return m;
}

/**********************************************************/
/* 'os' object */

static JSValue js_os_return(JSContext *ctx, ssize_t ret)
{
    if (ret < 0)
        ret = -errno;
    return JS_NewInt64(ctx, ret);
}

static JSValue js_os_open(JSContext *ctx, JSValueConst this_val,
                          int argc, JSValueConst *argv)
{
    const char *filename;
    int flags, mode, ret;

    filename = JS_ToCString(ctx, argv[0]);
    if (!filename)
        return JS_EXCEPTION;
    if (JS_ToInt32(ctx, &flags, argv[1]))
        goto fail;
    if (argc >= 3 && !JS_IsUndefined(argv[2])) {
        if (JS_ToInt32(ctx, &mode, argv[2])) {
        fail:
            JS_FreeCString(ctx, filename);
            return JS_EXCEPTION;
        }
    } else {
        mode = 0666;
    }
#if defined(_WIN32)
    /* force binary mode by default */
    if (!(flags & O_TEXT))
        flags |= O_BINARY;
#endif
    ret = open(filename, flags, mode);
    JS_FreeCString(ctx, filename);
    return js_os_return(ctx, ret);
}

static JSValue js_os_close(JSContext *ctx, JSValueConst this_val,
                           int argc, JSValueConst *argv)
{
    int fd, ret;
    if (JS_ToInt32(ctx, &fd, argv[0]))
        return JS_EXCEPTION;
    ret = close(fd);
    return js_os_return(ctx, ret);
}

static JSValue js_os_seek(JSContext *ctx, JSValueConst this_val,
                          int argc, JSValueConst *argv)
{
    int fd, whence, ret;
    int64_t pos;
    
    if (JS_ToInt32(ctx, &fd, argv[0]))
        return JS_EXCEPTION;
    if (JS_ToInt64(ctx, &pos, argv[1]))
        return JS_EXCEPTION;
    if (JS_ToInt32(ctx, &whence, argv[2]))
        return JS_EXCEPTION;
    ret = lseek(fd, pos, whence);
    return js_os_return(ctx, ret);
}

static JSValue js_os_read_write(JSContext *ctx, JSValueConst this_val,
                                      int argc, JSValueConst *argv, int magic)
{
    int fd;
    uint64_t pos, len;
    size_t size;
    ssize_t ret;
    uint8_t *buf;
    
    if (JS_ToInt32(ctx, &fd, argv[0]))
        return JS_EXCEPTION;
    if (JS_ToIndex(ctx, &pos, argv[2]))
        return JS_EXCEPTION;
    if (JS_ToIndex(ctx, &len, argv[3]))
        return JS_EXCEPTION;
    buf = JS_GetArrayBuffer(ctx, &size, argv[1]);
    if (!buf)
        return JS_EXCEPTION;
    if (pos + len > size)
        return JS_ThrowRangeError(ctx, "read/write array buffer overflow");
    if (magic)
        ret = write(fd, buf + pos, len);
    else
        ret = read(fd, buf + pos, len);
    return js_os_return(ctx, ret);
}

static JSValue js_os_isatty(JSContext *ctx, JSValueConst this_val,
                            int argc, JSValueConst *argv)
{
    int fd;
    if (JS_ToInt32(ctx, &fd, argv[0]))
        return JS_EXCEPTION;
    return JS_NewBool(ctx, isatty(fd) == 1);
}

#if defined(_WIN32)
static JSValue js_os_ttyGetWinSize(JSContext *ctx, JSValueConst this_val,
                                   int argc, JSValueConst *argv)
{
    int fd;
    HANDLE handle;
    CONSOLE_SCREEN_BUFFER_INFO info;
    JSValue obj;

    if (JS_ToInt32(ctx, &fd, argv[0]))
        return JS_EXCEPTION;
    handle = (HANDLE)_get_osfhandle(fd);
    
    if (!GetConsoleScreenBufferInfo(handle, &info))
        return JS_NULL;
    obj = JS_NewArray(ctx);
    if (JS_IsException(obj))
        return obj;
    JS_DefinePropertyValueUint32(ctx, obj, 0, JS_NewInt32(ctx, info.dwSize.X), JS_PROP_C_W_E);
    JS_DefinePropertyValueUint32(ctx, obj, 1, JS_NewInt32(ctx, info.dwSize.Y), JS_PROP_C_W_E);
    return obj;
}

static JSValue js_os_ttySetRaw(JSContext *ctx, JSValueConst this_val,
                               int argc, JSValueConst *argv)
{
    int fd;
    HANDLE handle;

    if (JS_ToInt32(ctx, &fd, argv[0]))
        return JS_EXCEPTION;
    handle = (HANDLE)_get_osfhandle(fd);
    
    SetConsoleMode(handle, ENABLE_WINDOW_INPUT);
    return JS_UNDEFINED;
}
#else
static JSValue js_os_ttyGetWinSize(JSContext *ctx, JSValueConst this_val,
                                   int argc, JSValueConst *argv)
{
    int fd;
    struct winsize ws;
    JSValue obj;
    
    if (JS_ToInt32(ctx, &fd, argv[0]))
        return JS_EXCEPTION;
    if (ioctl(fd, TIOCGWINSZ, &ws) == 0 &&
        ws.ws_col >= 4 && ws.ws_row >= 4) {
        obj = JS_NewArray(ctx);
        if (JS_IsException(obj))
            return obj;
        JS_DefinePropertyValueUint32(ctx, obj, 0, JS_NewInt32(ctx, ws.ws_col), JS_PROP_C_W_E);
        JS_DefinePropertyValueUint32(ctx, obj, 1, JS_NewInt32(ctx, ws.ws_row), JS_PROP_C_W_E);
        return obj;
    } else {
        return JS_NULL;
    }
}

static struct termios oldtty;

static void term_exit(void)
{
    tcsetattr(0, TCSANOW, &oldtty);
}

/* XXX: should add a way to go back to normal mode */
static JSValue js_os_ttySetRaw(JSContext *ctx, JSValueConst this_val,
                               int argc, JSValueConst *argv)
{
    struct termios tty;
    int fd;
    
    if (JS_ToInt32(ctx, &fd, argv[0]))
        return JS_EXCEPTION;
    
    memset(&tty, 0, sizeof(tty));
    tcgetattr(fd, &tty);
    oldtty = tty;

    tty.c_iflag &= ~(IGNBRK|BRKINT|PARMRK|ISTRIP
                          |INLCR|IGNCR|ICRNL|IXON);
    tty.c_oflag |= OPOST;
    tty.c_lflag &= ~(ECHO|ECHONL|ICANON|IEXTEN);
    tty.c_cflag &= ~(CSIZE|PARENB);
    tty.c_cflag |= CS8;
    tty.c_cc[VMIN] = 1;
    tty.c_cc[VTIME] = 0;

    tcsetattr(fd, TCSANOW, &tty);

    atexit(term_exit);
    return JS_UNDEFINED;
}

#endif /* !_WIN32 */

static JSValue js_os_remove(JSContext *ctx, JSValueConst this_val,
                             int argc, JSValueConst *argv)
{
    const char *filename;
    int ret;
    
    filename = JS_ToCString(ctx, argv[0]);
    if (!filename)
        return JS_EXCEPTION;
    ret = remove(filename);
    JS_FreeCString(ctx, filename);
    return js_os_return(ctx, ret);
}

static JSValue js_os_rename(JSContext *ctx, JSValueConst this_val,
                            int argc, JSValueConst *argv)
{
    const char *oldpath, *newpath;
    int ret;
    
    oldpath = JS_ToCString(ctx, argv[0]);
    if (!oldpath)
        return JS_EXCEPTION;
    newpath = JS_ToCString(ctx, argv[1]);
    if (!newpath) {
        JS_FreeCString(ctx, oldpath);
        return JS_EXCEPTION;
    }
    ret = rename(oldpath, newpath);
    JS_FreeCString(ctx, oldpath);
    JS_FreeCString(ctx, newpath);
    return js_os_return(ctx, ret);
}

static JSOSRWHandler *find_rh(int fd)
{
    JSOSRWHandler *rh;
    struct list_head *el;
    list_for_each(el, &os_rw_handlers) {
        rh = list_entry(el, JSOSRWHandler, link);
        if (rh->fd == fd)
            return rh;
    }
    return NULL;
}

static void free_rw_handler(JSRuntime *rt, JSOSRWHandler *rh)
{
    int i;
    list_del(&rh->link);
    for(i = 0; i < 2; i++) {
        JS_FreeValueRT(rt, rh->rw_func[i]);
    }
    js_free_rt(rt, rh);
}

static JSValue js_os_setReadHandler(JSContext *ctx, JSValueConst this_val,
                                    int argc, JSValueConst *argv, int magic)
{
    JSOSRWHandler *rh;
    int fd;
    JSValueConst func;
    
    if (JS_ToInt32(ctx, &fd, argv[0]))
        return JS_EXCEPTION;
    func = argv[1];
    if (JS_IsNull(func)) {
        rh = find_rh(fd);
        if (rh) {
            JS_FreeValue(ctx, rh->rw_func[magic]);
            rh->rw_func[magic] = JS_NULL;
            if (JS_IsNull(rh->rw_func[0]) &&
                JS_IsNull(rh->rw_func[1])) {
                /* remove the entry */
                free_rw_handler(JS_GetRuntime(ctx), rh);
            }
        }
    } else {
        if (!JS_IsFunction(ctx, func))
            return JS_ThrowTypeError(ctx, "not a function");
        rh = find_rh(fd);
        if (!rh) {
            rh = js_mallocz(ctx, sizeof(*rh));
            if (!rh)
                return JS_EXCEPTION;
            rh->fd = fd;
            rh->rw_func[0] = JS_NULL;
            rh->rw_func[1] = JS_NULL;
            list_add_tail(&rh->link, &os_rw_handlers);
        }
        JS_FreeValue(ctx, rh->rw_func[magic]);
        rh->rw_func[magic] = JS_DupValue(ctx, func);
    }
    return JS_UNDEFINED;
}

static JSOSSignalHandler *find_sh(int sig_num)
{
    JSOSSignalHandler *sh;
    struct list_head *el;
    list_for_each(el, &os_signal_handlers) {
        sh = list_entry(el, JSOSSignalHandler, link);
        if (sh->sig_num == sig_num)
            return sh;
    }
    return NULL;
}

static void free_sh(JSRuntime *rt, JSOSSignalHandler *sh)
{
    list_del(&sh->link);
    JS_FreeValueRT(rt, sh->func);
    js_free_rt(rt, sh);
}

static void os_signal_handler(int sig_num)
{
    os_pending_signals |= ((uint64_t)1 << sig_num);
}

#if defined(_WIN32)
typedef void (*sighandler_t)(int sig_num);
#endif

static JSValue js_os_signal(JSContext *ctx, JSValueConst this_val,
                            int argc, JSValueConst *argv)
{
    JSOSSignalHandler *sh;
    uint32_t sig_num;
    JSValueConst func;
    sighandler_t handler;
    
    if (JS_ToUint32(ctx, &sig_num, argv[0]))
        return JS_EXCEPTION;
    if (sig_num >= 64)
        return JS_ThrowRangeError(ctx, "invalid signal number");
    func = argv[1];
    /* func = null: SIG_DFL, func = undefined, SIG_IGN */
    if (JS_IsNull(func) || JS_IsUndefined(func)) {
        sh = find_sh(sig_num);
        if (sh) {
            free_sh(JS_GetRuntime(ctx), sh);
        }
        if (JS_IsNull(func))
            handler = SIG_DFL;
        else
            handler = SIG_IGN;
        signal(sig_num, handler);
    } else {
        if (!JS_IsFunction(ctx, func))
            return JS_ThrowTypeError(ctx, "not a function");
        sh = find_sh(sig_num);
        if (!sh) {
            sh = js_mallocz(ctx, sizeof(*sh));
            if (!sh)
                return JS_EXCEPTION;
            sh->sig_num = sig_num;
            list_add_tail(&sh->link, &os_signal_handlers);
        }
        JS_FreeValue(ctx, sh->func);
        sh->func = JS_DupValue(ctx, func);
        signal(sig_num, os_signal_handler);
    }
    return JS_UNDEFINED;
}

#if defined(__linux__) || defined(__APPLE__)
static int64_t get_time_ms(void)
{
    struct timespec ts;
    clock_gettime(CLOCK_MONOTONIC, &ts);
    return (uint64_t)ts.tv_sec * 1000 + (ts.tv_nsec / 1000000);
}
#else
/* more portable, but does not work if the date is updated */
static int64_t get_time_ms(void)
{
    struct timeval tv;
    gettimeofday(&tv, NULL);
    return (int64_t)tv.tv_sec * 1000 + (tv.tv_usec / 1000);
}
#endif

static void unlink_timer(JSRuntime *rt, JSOSTimer *th)
{
    if (th->link.prev) {
        list_del(&th->link);
        th->link.prev = th->link.next = NULL;
    }
}

static void free_timer(JSRuntime *rt, JSOSTimer *th)
{
    JS_FreeValueRT(rt, th->func);
    js_free_rt(rt, th);
}

static JSClassID js_os_timer_class_id;

static void js_os_timer_finalizer(JSRuntime *rt, JSValue val)
{
    JSOSTimer *th = JS_GetOpaque(val, js_os_timer_class_id);
    if (th) {
        th->has_object = FALSE;
        if (!th->link.prev)
            free_timer(rt, th);
    }
}

static void js_os_timer_mark(JSRuntime *rt, JSValueConst val,
                             JS_MarkFunc *mark_func)
{
    JSOSTimer *th = JS_GetOpaque(val, js_os_timer_class_id);
    if (th) {
        JS_MarkValue(rt, th->func, mark_func);
    }
}

static JSValue js_os_setTimeout(JSContext *ctx, JSValueConst this_val,
                                int argc, JSValueConst *argv)
{
    int64_t delay;
    JSValueConst func;
    JSOSTimer *th;
    JSValue obj;

    if (JS_ToInt64(ctx, &delay, argv[0]))
        return JS_EXCEPTION;
    func = argv[1];
    if (!JS_IsFunction(ctx, func))
        return JS_ThrowTypeError(ctx, "not a function");
    obj = JS_NewObjectClass(ctx, js_os_timer_class_id);
    if (JS_IsException(obj))
        return obj;
    th = js_mallocz(ctx, sizeof(*th));
    th->has_object = TRUE;
    if (!th) {
        JS_FreeValue(ctx, obj);
        return JS_EXCEPTION;
    }
    th->timeout = get_time_ms() + delay;
    th->func = JS_DupValue(ctx, func);
    list_add_tail(&th->link, &os_timers);
    JS_SetOpaque(obj, th);
    return obj;
}

static JSValue js_os_clearTimeout(JSContext *ctx, JSValueConst this_val,
                                  int argc, JSValueConst *argv)
{
    JSOSTimer *th = JS_GetOpaque2(ctx, argv[0], js_os_timer_class_id);
    if (!th)
        return JS_EXCEPTION;
    unlink_timer(JS_GetRuntime(ctx), th);
    return JS_UNDEFINED;
}

static JSClassDef js_os_timer_class = {
    "OSTimer",
    .finalizer = js_os_timer_finalizer,
    .gc_mark = js_os_timer_mark,
}; 

static void call_handler(JSContext *ctx, JSValueConst func)
{
    JSValue ret;
    ret = JS_Call(ctx, func, JS_UNDEFINED, 0, NULL);
    if (JS_IsException(ret))
        js_std_dump_error(ctx);
    JS_FreeValue(ctx, ret);
}

#if defined(_WIN32)

static int js_os_poll(JSContext *ctx)
{
    int min_delay, console_fd;
    int64_t cur_time, delay;
    JSOSRWHandler *rh;
    struct list_head *el;
    
    /* XXX: handle signals if useful */

    if (list_empty(&os_rw_handlers) && list_empty(&os_timers))
        return -1; /* no more events */
    
    /* XXX: only timers and basic console input are supported */
    if (!list_empty(&os_timers)) {
        cur_time = get_time_ms();
        min_delay = 10000;
        list_for_each(el, &os_timers) {
            JSOSTimer *th = list_entry(el, JSOSTimer, link);
            delay = th->timeout - cur_time;
            if (delay <= 0) {
                JSValue func;
                /* the timer expired */
                func = th->func;
                th->func = JS_UNDEFINED;
                unlink_timer(JS_GetRuntime(ctx), th);
                if (!th->has_object)
                    free_timer(JS_GetRuntime(ctx), th);
                call_handler(ctx, func);
                JS_FreeValue(ctx, func);
                return 0;
            } else if (delay < min_delay) {
                min_delay = delay;
            }
        }
    } else {
        min_delay = -1;
    }

    console_fd = -1;
    list_for_each(el, &os_rw_handlers) {
        rh = list_entry(el, JSOSRWHandler, link);
        if (rh->fd == 0 && !JS_IsNull(rh->rw_func[0])) {
            console_fd = rh->fd;
            break;
        }
    }

    if (console_fd >= 0) {
        DWORD ti, ret;
        HANDLE handle;
        if (min_delay == -1)
            ti = INFINITE;
        else
            ti = min_delay;
        handle = (HANDLE)_get_osfhandle(console_fd);
        ret = WaitForSingleObject(handle, ti);
        if (ret == WAIT_OBJECT_0) {
            list_for_each(el, &os_rw_handlers) {
                rh = list_entry(el, JSOSRWHandler, link);
                if (rh->fd == console_fd && !JS_IsNull(rh->rw_func[0])) {
                    call_handler(ctx, rh->rw_func[0]);
                    /* must stop because the list may have been modified */
                    break;
                }
            }
        }
    } else {
        Sleep(min_delay);
    }
    return 0;
}
#else
static int js_os_poll(JSContext *ctx)
{
    int ret, fd_max, min_delay;
    int64_t cur_time, delay;
    fd_set rfds, wfds;
    JSOSRWHandler *rh;
    struct list_head *el;
    struct timeval tv, *tvp;

    if (unlikely(os_pending_signals != 0)) {
        JSOSSignalHandler *sh;
        uint64_t mask;
        
        list_for_each(el, &os_signal_handlers) {
            sh = list_entry(el, JSOSSignalHandler, link);
            mask = (uint64_t)1 << sh->sig_num;
            if (os_pending_signals & mask) {
                os_pending_signals &= ~mask;
                call_handler(ctx, sh->func);
                return 0;
            }
        }
    }
    
    if (list_empty(&os_rw_handlers) && list_empty(&os_timers))
        return -1; /* no more events */
    
    if (!list_empty(&os_timers)) {
        cur_time = get_time_ms();
        min_delay = 10000;
        list_for_each(el, &os_timers) {
            JSOSTimer *th = list_entry(el, JSOSTimer, link);
            delay = th->timeout - cur_time;
            if (delay <= 0) {
                JSValue func;
                /* the timer expired */
                func = th->func;
                th->func = JS_UNDEFINED;
                unlink_timer(JS_GetRuntime(ctx), th);
                if (!th->has_object)
                    free_timer(JS_GetRuntime(ctx), th);
                call_handler(ctx, func);
                JS_FreeValue(ctx, func);
                return 0;
            } else if (delay < min_delay) {
                min_delay = delay;
            }
        }
        tv.tv_sec = min_delay / 1000;
        tv.tv_usec = (min_delay % 1000) * 1000;
        tvp = &tv;
    } else {
        tvp = NULL;
    }
    
    FD_ZERO(&rfds);
    FD_ZERO(&wfds);
    fd_max = -1;
    list_for_each(el, &os_rw_handlers) {
        rh = list_entry(el, JSOSRWHandler, link);
        fd_max = max_int(fd_max, rh->fd);
        if (!JS_IsNull(rh->rw_func[0]))
            FD_SET(rh->fd, &rfds);
        if (!JS_IsNull(rh->rw_func[1]))
            FD_SET(rh->fd, &wfds);
    }
    
    ret = select(fd_max + 1, &rfds, &wfds, NULL, tvp);
    if (ret > 0) {
        list_for_each(el, &os_rw_handlers) {
            rh = list_entry(el, JSOSRWHandler, link);
            if (!JS_IsNull(rh->rw_func[0]) &&
                FD_ISSET(rh->fd, &rfds)) {
                call_handler(ctx, rh->rw_func[0]);
                /* must stop because the list may have been modified */
                break;
            }
            if (!JS_IsNull(rh->rw_func[1])) {
                FD_SET(rh->fd, &wfds);
                call_handler(ctx, rh->rw_func[1]);
                /* must stop because the list may have been modified */
                break;
            }
        }
    }
    return 0;
}
#endif /* !_WIN32 */

#if defined(_WIN32)
#define OS_PLATFORM "win32"
#elif defined(__APPLE__)
#define OS_PLATFORM "darwin"
#elif defined(EMSCRIPTEN)
#define OS_PLATFORM "js"
#else
#define OS_PLATFORM "linux"
#endif

#define OS_FLAG(x) JS_PROP_INT32_DEF(#x, x, JS_PROP_CONFIGURABLE )

static const JSCFunctionListEntry js_os_funcs[] = {
    JS_CFUNC_DEF("open", 2, js_os_open ),
    OS_FLAG(O_RDONLY),
    OS_FLAG(O_WRONLY),
    OS_FLAG(O_RDWR),
    OS_FLAG(O_APPEND),
    OS_FLAG(O_CREAT),
    OS_FLAG(O_EXCL),
    OS_FLAG(O_TRUNC),
#if defined(_WIN32)
    OS_FLAG(O_BINARY),
    OS_FLAG(O_TEXT),
#endif
    JS_CFUNC_DEF("close", 1, js_os_close ),
    JS_CFUNC_DEF("seek", 3, js_os_seek ),
    JS_CFUNC_MAGIC_DEF("read", 4, js_os_read_write, 0 ),
    JS_CFUNC_MAGIC_DEF("write", 4, js_os_read_write, 1 ),
    JS_CFUNC_DEF("isatty", 1, js_os_isatty ),
    JS_CFUNC_DEF("ttyGetWinSize", 1, js_os_ttyGetWinSize ),
    JS_CFUNC_DEF("ttySetRaw", 1, js_os_ttySetRaw ),
    JS_CFUNC_DEF("remove", 1, js_os_remove ),
    JS_CFUNC_DEF("rename", 2, js_os_rename ),
    JS_CFUNC_MAGIC_DEF("setReadHandler", 2, js_os_setReadHandler, 0 ),
    JS_CFUNC_MAGIC_DEF("setWriteHandler", 2, js_os_setReadHandler, 1 ),
    JS_CFUNC_DEF("signal", 2, js_os_signal ),
    OS_FLAG(SIGINT),
    OS_FLAG(SIGABRT),
    OS_FLAG(SIGFPE),
    OS_FLAG(SIGILL),
    OS_FLAG(SIGSEGV),
    OS_FLAG(SIGTERM),
    JS_CFUNC_DEF("setTimeout", 2, js_os_setTimeout ),
    JS_CFUNC_DEF("clearTimeout", 1, js_os_clearTimeout ),
    JS_PROP_STRING_DEF("platform", OS_PLATFORM, 0 ),
    /* stat, readlink, opendir, closedir, ... */
};

static int js_os_init(JSContext *ctx, JSModuleDef *m)
{
    os_poll_func = js_os_poll;
    
    /* OSTimer class */
    JS_NewClassID(&js_os_timer_class_id);
    JS_NewClass(JS_GetRuntime(ctx), js_os_timer_class_id, &js_os_timer_class);
    
    return JS_SetModuleExportList(ctx, m, js_os_funcs,
                                  countof(js_os_funcs));
}

JSModuleDef *js_init_module_os(JSContext *ctx, const char *module_name)
{
    JSModuleDef *m;
    m = JS_NewCModule(ctx, module_name, js_os_init);
    if (!m)
        return NULL;
    JS_AddModuleExportList(ctx, m, js_os_funcs, countof(js_os_funcs));
    return m;
}

/**********************************************************/

static JSValue js_print(JSContext *ctx, JSValueConst this_val,
                              int argc, JSValueConst *argv)
{
    int i;
    const char *str;

    for(i = 0; i < argc; i++) {
        if (i != 0)
            putchar(' ');
        str = JS_ToCString(ctx, argv[i]);
        if (!str)
            return JS_EXCEPTION;
        fputs(str, stdout);
        JS_FreeCString(ctx, str);
    }
    putchar('\n');
    return JS_UNDEFINED;
}

void js_std_add_helpers(JSContext *ctx, int argc, char **argv)
{
    JSValue global_obj, console, args;
    int i;

    /* XXX: should these global definitions be enumerable? */
    global_obj = JS_GetGlobalObject(ctx);

    console = JS_NewObject(ctx);
    JS_SetPropertyStr(ctx, console, "log",
                      JS_NewCFunction(ctx, js_print, "log", 1));
    JS_SetPropertyStr(ctx, global_obj, "console", console);

    /* same methods as the mozilla JS shell */
    args = JS_NewArray(ctx);
    for(i = 0; i < argc; i++) {
        JS_SetPropertyUint32(ctx, args, i, JS_NewString(ctx, argv[i]));
    }
    JS_SetPropertyStr(ctx, global_obj, "scriptArgs", args);

    JS_SetPropertyStr(ctx, global_obj, "print",
                      JS_NewCFunction(ctx, js_print, "print", 1));
    JS_SetPropertyStr(ctx, global_obj, "__loadScript",
                      JS_NewCFunction(ctx, js_loadScript, "__loadScript", 1));
    
    JS_FreeValue(ctx, global_obj);

    /* XXX: not multi-context */
    init_list_head(&os_rw_handlers);
    init_list_head(&os_signal_handlers);
    init_list_head(&os_timers);
    os_pending_signals = 0;
}

void js_std_free_handlers(JSRuntime *rt)
{
    struct list_head *el, *el1;

    list_for_each_safe(el, el1, &os_rw_handlers) {
        JSOSRWHandler *rh = list_entry(el, JSOSRWHandler, link);
        free_rw_handler(rt, rh);
    }

    list_for_each_safe(el, el1, &os_signal_handlers) {
        JSOSSignalHandler *sh = list_entry(el, JSOSSignalHandler, link);
        free_sh(rt, sh);
    }
    
    list_for_each_safe(el, el1, &os_timers) {
        JSOSTimer *th = list_entry(el, JSOSTimer, link);
        unlink_timer(rt, th);
        if (!th->has_object)
            free_timer(rt, th);
    }
}

void js_std_dump_error(JSContext *ctx)
{
    JSValue exception_val, val;
    const char *stack;
    BOOL is_error;
    
    exception_val = JS_GetException(ctx);
    is_error = JS_IsError(ctx, exception_val);
    if (!is_error)
        printf("Throw: ");
    js_print(ctx, JS_NULL, 1, (JSValueConst *)&exception_val);
    if (is_error) {
        val = JS_GetPropertyStr(ctx, exception_val, "stack");
        if (!JS_IsUndefined(val)) {
            stack = JS_ToCString(ctx, val);
            printf("%s\n", stack);
            JS_FreeCString(ctx, stack);
        }
        JS_FreeValue(ctx, val);
    }
    JS_FreeValue(ctx, exception_val);
}

/* main loop which calls the user JS callbacks */
void js_std_loop(JSContext *ctx)
{
    JSContext *ctx1;
    int err;

    for(;;) {
        /* execute the pending jobs */
        for(;;) {
            err = JS_ExecutePendingJob(JS_GetRuntime(ctx), &ctx1);
            if (err <= 0) {
                if (err < 0) {
                    js_std_dump_error(ctx1);
                }
                break;
            }
        }

        if (!os_poll_func || os_poll_func(ctx))
            break;
    }
}

void js_std_eval_binary(JSContext *ctx, const uint8_t *buf, size_t buf_len,
                        int flags)
{
    JSValue val;
    val = JS_EvalBinary(ctx, buf, buf_len, flags);
    if (JS_IsException(val)) {
        js_std_dump_error(ctx);
        exit(1);
    }
    JS_FreeValue(ctx, val);
}