// System tests for compiling C code.
//
// Copyright 2016 Mozilla Foundation
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#![deny(rust_2018_idioms)]
#![allow(dead_code, unused_imports)]

#[macro_use]
extern crate log;
use crate::harness::{
    cachepot_client_cfg, cachepot_command, get_stats, start_local_daemon, stop_local_daemon,
    write_json_cfg, write_source, zero_stats,
};
use assert_cmd::prelude::*;
use cachepot::util::fs::{self, File};
use log::Level::Trace;
use predicates::prelude::*;
use std::collections::HashMap;
use std::env;
use std::ffi::{OsStr, OsString};
use std::fmt;
use std::io::{self, Read, Write};
use std::path::{Path, PathBuf};
use std::process::{Command, Output, Stdio};
use std::str;
use which::which_in;

mod harness;

#[derive(Clone)]
struct Compiler {
    pub name: &'static str,
    pub exe: OsString,
    pub env_vars: Vec<(OsString, OsString)>,
}

// Test GCC + clang on non-OS X platforms.
#[cfg(all(unix, not(target_os = "macos")))]
const COMPILERS: &[&str] = &["gcc", "clang"];

// OS X ships a `gcc` that's just a clang wrapper, so only test clang there.
#[cfg(target_os = "macos")]
const COMPILERS: &[&str] = &["clang"];

//TODO: could test gcc when targeting mingw.

macro_rules! vec_from {
    ( $t:ty, $( $x:expr ),* ) => {
        vec!($( Into::<$t>::into(&$x), )*)
    };
}

// TODO: This will fail if gcc/clang is actually a ccache wrapper, as it is the
// default case on Fedora, e.g.
fn compile_cmdline<T: AsRef<OsStr>>(
    compiler: &str,
    exe: T,
    input: &str,
    output: &str,
) -> Vec<OsString> {
    match compiler {
        "gcc" | "clang" => vec_from!(OsString, exe.as_ref(), "-c", input, "-o", output),
        "cl.exe" => vec_from!(OsString, exe, "-c", input, format!("-Fo{}", output)),
        _ => panic!("Unsupported compiler: {}", compiler),
    }
}

const INPUT: &str = "test.c";
const INPUT_ERR: &str = "test_err.c";
const INPUT_MACRO_EXPANSION: &str = "test_macro_expansion.c";
const INPUT_WITH_DEFINE: &str = "test_with_define.c";
const OUTPUT: &str = "test.o";

// Copy the source files into the tempdir so we can compile with relative paths, since the commandline winds up in the hash key.
fn copy_to_tempdir(inputs: &[&str], tempdir: &Path) {
    for f in inputs {
        let original_source_file = Path::new(file!()).parent().unwrap().join(&*f);
        let source_file = tempdir.join(f);
        trace!("fs::copy({:?}, {:?})", original_source_file, source_file);
        fs::copy(&original_source_file, &source_file).unwrap();
    }
}

fn test_basic_compile(compiler: Compiler, tempdir: &Path) {
    let Compiler {
        name,
        exe,
        env_vars,
    } = compiler;
    trace!("run_cachepot_command_test: {}", name);
    // Compile a source file.
    copy_to_tempdir(&[INPUT, INPUT_ERR], tempdir);

    let out_file = tempdir.join("test.o");
    trace!("compile");
    cachepot_command()
        .args(&compile_cmdline(name, &exe, INPUT, OUTPUT))
        .current_dir(tempdir)
        .envs(env_vars.clone())
        .assert()
        .success();
    assert!(fs::metadata(&out_file).map(|m| m.len() > 0).unwrap());
    trace!("request stats");
    get_stats(|info| {
        assert_eq!(1, info.stats.compile_requests);
        assert_eq!(1, info.stats.requests_executed);
        assert_eq!(0, info.stats.cache_hits.all());
        assert_eq!(1, info.stats.cache_misses.all());
        assert_eq!(&1, info.stats.cache_misses.get("C/C++").unwrap());
    });
    trace!("compile");
    fs::remove_file(&out_file).unwrap();
    cachepot_command()
        .args(&compile_cmdline(name, &exe, INPUT, OUTPUT))
        .current_dir(tempdir)
        .envs(env_vars)
        .assert()
        .success();
    assert!(fs::metadata(&out_file).map(|m| m.len() > 0).unwrap());
    trace!("request stats");
    get_stats(|info| {
        assert_eq!(2, info.stats.compile_requests);
        assert_eq!(2, info.stats.requests_executed);
        assert_eq!(1, info.stats.cache_hits.all());
        assert_eq!(1, info.stats.cache_misses.all());
        assert_eq!(&1, info.stats.cache_hits.get("C/C++").unwrap());
        assert_eq!(&1, info.stats.cache_misses.get("C/C++").unwrap());
    });
}

fn test_noncacheable_stats(compiler: Compiler, tempdir: &Path) {
    let Compiler {
        name,
        exe,
        env_vars,
    } = compiler;
    trace!("test_noncacheable_stats: {}", name);
    copy_to_tempdir(&[INPUT], tempdir);

    trace!("compile");
    cachepot_command()
        .arg(&exe)
        .arg("-E")
        .arg(INPUT)
        .current_dir(tempdir)
        .envs(env_vars)
        .assert()
        .success();
    trace!("request stats");
    get_stats(|info| {
        assert_eq!(1, info.stats.compile_requests);
        assert_eq!(0, info.stats.requests_executed);
        assert_eq!(1, info.stats.not_cached.len());
        assert_eq!(Some(&1), info.stats.not_cached.get("-E"));
    });
}

fn test_msvc_deps(compiler: Compiler, tempdir: &Path) {
    let Compiler {
        name,
        exe,
        env_vars,
    } = compiler;
    // Check that -deps works.
    trace!("compile with -deps");
    let mut args = compile_cmdline(name, &exe, INPUT, OUTPUT);
    args.push("-depstest.d".into());
    cachepot_command()
        .args(&args)
        .current_dir(tempdir)
        .envs(env_vars)
        .assert()
        .success();
    // Check the contents
    let mut f = File::open(tempdir.join("test.d")).expect("Failed to open dep file");
    let mut buf = String::new();
    // read_to_string should be safe because we're supplying all the filenames here,
    // and there are no absolute paths.
    f.read_to_string(&mut buf).expect("Failed to read dep file");
    let lines: Vec<_> = buf.lines().map(|l| l.trim_end()).collect();
    let expected = format!(
        "{output}: {input}\n{input}:\n",
        output = OUTPUT,
        input = INPUT
    );
    let expected_lines: Vec<_> = expected.lines().collect();
    assert_eq!(lines, expected_lines);
}

fn test_gcc_mp_werror(compiler: Compiler, tempdir: &Path) {
    let Compiler {
        name,
        exe,
        env_vars,
    } = compiler;
    trace!("test -MP with -Werror");
    let mut args = compile_cmdline(name, &exe, INPUT_ERR, OUTPUT);
    args.extend(vec_from!(
        OsString, "-MD", "-MP", "-MF", "foo.pp", "-Werror"
    ));
    // This should fail, but the error should be from the #error!
    cachepot_command()
        .args(&args)
        .current_dir(tempdir)
        .envs(env_vars)
        .assert()
        .failure()
        .stderr(
            predicates::str::contains("to generate dependencies you must specify either -M or -MM")
                .from_utf8()
                .not(),
        );
}

fn test_gcc_fprofile_generate_source_changes(compiler: Compiler, tempdir: &Path) {
    let Compiler {
        name,
        exe,
        env_vars,
    } = compiler;
    trace!("test -fprofile-generate with different source inputs");
    zero_stats();
    const SRC: &str = "source.c";
    write_source(
        tempdir,
        SRC,
        "/*line 1*/
#ifndef UNDEFINED
/*unused line 1*/
#endif

int main(int argc, char** argv) {
  return 0;
}
",
    );
    let mut args = compile_cmdline(name, &exe, SRC, OUTPUT);
    args.extend(vec_from!(OsString, "-fprofile-generate"));
    trace!("compile source.c (1)");
    cachepot_command()
        .args(&args)
        .current_dir(tempdir)
        .envs(env_vars.clone())
        .assert()
        .success();
    get_stats(|info| {
        assert_eq!(0, info.stats.cache_hits.all());
        assert_eq!(1, info.stats.cache_misses.all());
        assert_eq!(&1, info.stats.cache_misses.get("C/C++").unwrap());
    });
    // Compile the same source again to ensure we can get a cache hit.
    trace!("compile source.c (2)");
    cachepot_command()
        .args(&args)
        .current_dir(tempdir)
        .envs(env_vars.clone())
        .assert()
        .success();
    get_stats(|info| {
        assert_eq!(1, info.stats.cache_hits.all());
        assert_eq!(1, info.stats.cache_misses.all());
        assert_eq!(&1, info.stats.cache_hits.get("C/C++").unwrap());
        assert_eq!(&1, info.stats.cache_misses.get("C/C++").unwrap());
    });
    // Now write out a slightly different source file that will preprocess to the same thing,
    // modulo line numbers. This should not be a cache hit because line numbers are important
    // with -fprofile-generate.
    write_source(
        tempdir,
        SRC,
        "/*line 1*/
#ifndef UNDEFINED
/*unused line 1*/
/*unused line 2*/
#endif

int main(int argc, char** argv) {
  return 0;
}
",
    );
    trace!("compile source.c (3)");
    cachepot_command()
        .args(&args)
        .current_dir(tempdir)
        .envs(env_vars)
        .assert()
        .success();
    get_stats(|info| {
        assert_eq!(1, info.stats.cache_hits.all());
        assert_eq!(2, info.stats.cache_misses.all());
        assert_eq!(&1, info.stats.cache_hits.get("C/C++").unwrap());
        assert_eq!(&2, info.stats.cache_misses.get("C/C++").unwrap());
    });
}

fn test_gcc_clang_no_warnings_from_macro_expansion(compiler: Compiler, tempdir: &Path) {
    let Compiler {
        name,
        exe,
        env_vars,
    } = compiler;
    trace!("test_gcc_clang_no_warnings_from_macro_expansion: {}", name);
    // Compile a source file.
    copy_to_tempdir(&[INPUT_MACRO_EXPANSION], tempdir);

    trace!("compile");
    cachepot_command()
        .args(
            [
                &compile_cmdline(name, &exe, INPUT_MACRO_EXPANSION, OUTPUT)[..],
                &vec_from!(OsString, "-Wunreachable-code")[..],
            ]
            .concat(),
        )
        .current_dir(tempdir)
        .envs(env_vars)
        .assert()
        .success()
        .stderr(predicates::str::contains("warning:").from_utf8().not());
}

fn test_compile_with_define(compiler: Compiler, tempdir: &Path) {
    let Compiler {
        name,
        exe,
        env_vars,
    } = compiler;
    trace!("test_compile_with_define: {}", name);
    // Compile a source file.
    copy_to_tempdir(&[INPUT_WITH_DEFINE], tempdir);

    trace!("compile");
    cachepot_command()
        .args(
            [
                &compile_cmdline(name, &exe, INPUT_WITH_DEFINE, OUTPUT)[..],
                &vec_from!(OsString, "-DCACHEPOT_TEST_DEFINE")[..],
            ]
            .concat(),
        )
        .current_dir(tempdir)
        .envs(env_vars)
        .assert()
        .success()
        .stderr(predicates::str::contains("warning:").from_utf8().not());
}

fn run_cachepot_command_tests(compiler: Compiler, tempdir: &Path) {
    test_basic_compile(compiler.clone(), tempdir);
    test_compile_with_define(compiler.clone(), tempdir);
    if compiler.name == "cl.exe" {
        test_msvc_deps(compiler.clone(), tempdir);
    }
    if compiler.name == "gcc" {
        test_gcc_mp_werror(compiler.clone(), tempdir);
        test_gcc_fprofile_generate_source_changes(compiler.clone(), tempdir);
    }
    if compiler.name == "clang" || compiler.name == "gcc" {
        test_gcc_clang_no_warnings_from_macro_expansion(compiler, tempdir);
    }
}

#[cfg(unix)]
fn find_compilers() -> Vec<Compiler> {
    let cwd = env::current_dir().unwrap();
    COMPILERS
        .iter()
        .filter_map(|c| match which_in(c, env::var_os("PATH"), &cwd) {
            Ok(full_path) => match full_path.canonicalize() {
                Ok(full_path_canon) => Some(Compiler {
                    name: *c,
                    exe: full_path_canon.into_os_string(),
                    env_vars: vec![],
                }),
                Err(_) => None,
            },
            Err(_) => None,
        })
        .collect::<Vec<_>>()
}

#[cfg(target_env = "msvc")]
fn find_compilers() -> Vec<Compiler> {
    let tool = cc::Build::new()
        .opt_level(1)
        .host("x86_64-pc-windows-msvc")
        .target("x86_64-pc-windows-msvc")
        .debug(false)
        .get_compiler();
    vec![Compiler {
        name: "cl.exe",
        exe: tool.path().as_os_str().to_os_string(),
        env_vars: tool.env().to_vec(),
    }]
}

// TODO: This runs multiple test cases, for multiple compilers. It should be
// split up to run them individually. In the current form, it is hard to see
// which sub test cases are executed, and if one fails, the remaining tests
// are not run.
#[test]
#[cfg(any(unix, target_env = "msvc"))]
fn test_cachepot_command() {
    let _ = env_logger::Builder::new().is_test(true).try_init();
    let tempdir = tempfile::Builder::new()
        .prefix("cachepot_system_test")
        .tempdir()
        .unwrap();
    let compilers = find_compilers();
    if compilers.is_empty() {
        warn!("No compilers found, skipping test");
    } else {
        // Ensure there's no existing cachepot server running.
        stop_local_daemon();
        // Create the configurations
        let cachepot_cfg = cachepot_client_cfg(tempdir.path());
        write_json_cfg(tempdir.path(), "cachepot-cfg.json", &cachepot_cfg);
        let cachepot_cached_cfg_path = tempdir.path().join("cachepot-cached-cfg");
        // Start a server.
        start_local_daemon(
            &tempdir.path().join("cachepot-cfg.json"),
            &cachepot_cached_cfg_path,
        );
        for compiler in compilers {
            run_cachepot_command_tests(compiler, tempdir.path());
            zero_stats();
        }
        stop_local_daemon();
    }
}