// Copyright 2018-2022 the Deno authors. All rights reserved. MIT license.

use super::io::StdFileResource;
use deno_core::error::AnyError;
use deno_core::op;
use deno_core::Extension;
use deno_core::OpState;
use deno_core::ResourceId;
use serde::Deserialize;
use serde::Serialize;
use std::io::Error;

#[cfg(unix)]
use nix::sys::termios;

#[cfg(windows)]
use deno_core::error::custom_error;
#[cfg(windows)]
use winapi::shared::minwindef::DWORD;
#[cfg(windows)]
use winapi::um::wincon;
#[cfg(windows)]
const RAW_MODE_MASK: DWORD =
    wincon::ENABLE_LINE_INPUT | wincon::ENABLE_ECHO_INPUT | wincon::ENABLE_PROCESSED_INPUT;

#[cfg(windows)]
fn get_windows_handle(f: &std::fs::File) -> Result<std::os::windows::io::RawHandle, AnyError> {
    use std::os::windows::io::AsRawHandle;
    use winapi::um::handleapi;

    let handle = f.as_raw_handle();
    if handle == handleapi::INVALID_HANDLE_VALUE {
        return Err(Error::last_os_error().into());
    } else if handle.is_null() {
        return Err(custom_error("ReferenceError", "null handle"));
    }
    Ok(handle)
}

pub fn init() -> Extension {
    Extension::builder()
        .ops(vec![
            op_set_raw::decl(),
            op_isatty::decl(),
            op_console_size::decl(),
        ])
        .build()
}

#[derive(Deserialize)]
#[serde(rename_all = "camelCase")]
pub struct SetRawOptions {
    cbreak: bool,
}

#[derive(Deserialize)]
pub struct SetRawArgs {
    rid: ResourceId,
    mode: bool,
    options: SetRawOptions,
}

#[op]
fn op_set_raw(state: &mut OpState, args: SetRawArgs) -> Result<(), AnyError> {
    super::check_unstable(state, "Deno.setRaw");

    let rid = args.rid;
    let is_raw = args.mode;
    let cbreak = args.options.cbreak;

    // From https://github.com/kkawakam/rustyline/blob/master/src/tty/windows.rs
    // and https://github.com/kkawakam/rustyline/blob/master/src/tty/unix.rs
    // and https://github.com/crossterm-rs/crossterm/blob/e35d4d2c1cc4c919e36d242e014af75f6127ab50/src/terminal/sys/windows.rs
    // Copyright (c) 2015 Katsu Kawakami & Rustyline authors. MIT license.
    // Copyright (c) 2019 Timon. MIT license.
    #[cfg(windows)]
    {
        use std::os::windows::io::AsRawHandle;
        use winapi::shared::minwindef::FALSE;
        use winapi::um::{consoleapi, handleapi};

        if cbreak {
            return Err(deno_core::error::not_supported());
        }

        StdFileResource::with_file(state, rid, move |std_file| {
            let handle = std_file.as_raw_handle();

            if handle == handleapi::INVALID_HANDLE_VALUE {
                return Err(Error::last_os_error().into());
            } else if handle.is_null() {
                return Err(custom_error("ReferenceError", "null handle"));
            }
            let mut original_mode: DWORD = 0;
            // SAFETY: winapi call
            if unsafe { consoleapi::GetConsoleMode(handle, &mut original_mode) } == FALSE {
                return Err(Error::last_os_error().into());
            }
            let new_mode = if is_raw {
                original_mode & !RAW_MODE_MASK
            } else {
                original_mode | RAW_MODE_MASK
            };
            // SAFETY: winapi call
            if unsafe { consoleapi::SetConsoleMode(handle, new_mode) } == FALSE {
                return Err(Error::last_os_error().into());
            }

            Ok(())
        })
    }
    #[cfg(unix)]
    {
        use std::os::unix::io::AsRawFd;

        StdFileResource::with_file_and_metadata(state, rid, move |std_file, meta_data| {
            let raw_fd = std_file.as_raw_fd();
            let maybe_tty_mode = &mut meta_data.tty.mode;

            if is_raw {
                if maybe_tty_mode.is_none() {
                    // Save original mode.
                    let original_mode = termios::tcgetattr(raw_fd)?;
                    maybe_tty_mode.replace(original_mode);
                }

                let mut raw = maybe_tty_mode.clone().unwrap();

                raw.input_flags &= !(termios::InputFlags::BRKINT
                    | termios::InputFlags::ICRNL
                    | termios::InputFlags::INPCK
                    | termios::InputFlags::ISTRIP
                    | termios::InputFlags::IXON);

                raw.control_flags |= termios::ControlFlags::CS8;

                raw.local_flags &= !(termios::LocalFlags::ECHO
                    | termios::LocalFlags::ICANON
                    | termios::LocalFlags::IEXTEN);
                if !cbreak {
                    raw.local_flags &= !(termios::LocalFlags::ISIG);
                }
                raw.control_chars[termios::SpecialCharacterIndices::VMIN as usize] = 1;
                raw.control_chars[termios::SpecialCharacterIndices::VTIME as usize] = 0;
                termios::tcsetattr(raw_fd, termios::SetArg::TCSADRAIN, &raw)?;
            } else {
                // Try restore saved mode.
                if let Some(mode) = maybe_tty_mode.take() {
                    termios::tcsetattr(raw_fd, termios::SetArg::TCSADRAIN, &mode)?;
                }
            }

            Ok(())
        })
    }
}

#[op]
fn op_isatty(state: &mut OpState, rid: ResourceId) -> Result<bool, AnyError> {
    let isatty: bool = StdFileResource::with_file(state, rid, move |std_file| {
        #[cfg(windows)]
        {
            use winapi::shared::minwindef::FALSE;
            use winapi::um::consoleapi;

            let handle = get_windows_handle(std_file)?;
            let mut test_mode: DWORD = 0;
            // If I cannot get mode out of console, it is not a console.
            // TODO(bartlomieju):
            #[allow(clippy::undocumented_unsafe_blocks)]
            Ok(unsafe { consoleapi::GetConsoleMode(handle, &mut test_mode) != FALSE })
        }
        #[cfg(unix)]
        {
            use std::os::unix::io::AsRawFd;
            let raw_fd = std_file.as_raw_fd();
            // TODO(bartlomieju):
            #[allow(clippy::undocumented_unsafe_blocks)]
            Ok(unsafe { libc::isatty(raw_fd as libc::c_int) == 1 })
        }
    })?;
    Ok(isatty)
}

#[derive(Serialize)]
struct ConsoleSize {
    columns: u32,
    rows: u32,
}

#[op]
fn op_console_size(state: &mut OpState, rid: ResourceId) -> Result<ConsoleSize, AnyError> {
    super::check_unstable(state, "Deno.consoleSize");

    let size = StdFileResource::with_file(state, rid, move |std_file| {
        #[cfg(windows)]
        {
            use std::os::windows::io::AsRawHandle;
            let handle = std_file.as_raw_handle();

            // SAFETY: winapi calls
            unsafe {
                let mut bufinfo: winapi::um::wincon::CONSOLE_SCREEN_BUFFER_INFO =
                    std::mem::zeroed();

                if winapi::um::wincon::GetConsoleScreenBufferInfo(handle, &mut bufinfo) == 0 {
                    return Err(Error::last_os_error().into());
                }

                Ok(ConsoleSize {
                    columns: bufinfo.dwSize.X as u32,
                    rows: bufinfo.dwSize.Y as u32,
                })
            }
        }

        #[cfg(unix)]
        {
            use std::os::unix::io::AsRawFd;

            let fd = std_file.as_raw_fd();
            // TODO(bartlomieju):
            #[allow(clippy::undocumented_unsafe_blocks)]
            unsafe {
                let mut size: libc::winsize = std::mem::zeroed();
                if libc::ioctl(fd, libc::TIOCGWINSZ, &mut size as *mut _) != 0 {
                    return Err(Error::last_os_error().into());
                }

                // TODO (caspervonb) return a tuple instead
                Ok(ConsoleSize {
                    columns: size.ws_col as u32,
                    rows: size.ws_row as u32,
                })
            }
        }
    })?;

    Ok(size)
}