/*
 * Copyright (c) 2024. The RigelA open source project team and
 * its contributors reserve all rights.
 *
 * 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.
 */

#![doc = include_str!("../README.md")]

//! 尝试更现代化的开源读屏项目：
//! [RigelA](https://gitcode.net/mzdk100/rigela.git)

use libloading::{Library, Symbol};
use std::{
    env::var,
    io::{Error, ErrorKind},
    path::Path,
    sync::OnceLock,
};

#[cfg(target_arch = "x86")]
const LIB_NAME: &str = "ZDSRAPI.dll";
//noinspection SpellCheckingInspection
#[cfg(target_arch = "x86_64")]
const LIB_NAME: &str = "ZDSRAPI_x64.dll";
static LIB: OnceLock<Library> = OnceLock::new();

/// 初始化语音接口
///
/// # Arguments
///
/// * `r#type`: 0 读屏通道; 1 独立通道
/// * `channel_name`: type为0时忽略,传入NULL; type为1时:独立通道名称, NULL或空字符串时,将使用默认名称"API"
/// * `key_down_interrupt`: TRUE 按键打断; FALSE 按键不打断
///
/// returns: Result<i32, Error>
///     0: 成功
///     1: 版本不匹配
///
/// # Examples
///
/// ```
/// use zdsr_api::init_tts;
/// init_tts(0, std::ptr::null(), 0).unwrap();
/// ```
pub fn init_tts(
    r#type: i32,
    channel_name: *const u16,
    key_down_interrupt: i32,
) -> Result<i32, Error> {
    let win_dir = var("WINDIR").unwrap();
    let lib_path = Path::new(&win_dir)
        .parent()
        .unwrap()
        .join("Program Files (x86)")
        .join("zdsr")
        .join("zdsr")
        .join(LIB_NAME);
    if !lib_path.exists() {
        return Err(Error::last_os_error());
    }
    let res = unsafe {
        let lib = LIB.get_or_init(move || Library::new(lib_path).unwrap());
        let func: Symbol<unsafe extern "C" fn(i32, *const u16, i32) -> i32> =
            lib.get(b"InitTTS\0").unwrap();
        func(r#type, channel_name, key_down_interrupt)
    };
    Ok(res)
}

/// 朗读文本
///
/// # Arguments
///
/// * `text`: 要朗读的文本,Unicode
/// * `interrupt`: TRUE:清空排队,立刻打断朗读, FALSE:等待空闲时朗读
///
/// returns: Result<i32, Error>
///     0: 成功
///     1: 版本不匹配
///     2: ZDSR没有运行
///
/// # Examples
///
///```
/// use zdsr_api::speak;
/// // Speak: ABC
/// speak([65u16, 66, 67].as_ptr(), 0).unwrap();
/// ```
pub fn speak(text: *const u16, interrupt: i32) -> Result<i32, Error> {
    let Some(lib) = LIB.get() else {
        return Err(Error::new(
            ErrorKind::Other,
            "Can't find or init zdsr library.",
        ));
    };
    let res = unsafe {
        let func: Symbol<unsafe extern "C" fn(*const u16, i32) -> i32> =
            lib.get(b"Speak\0").unwrap();
        func(text, interrupt)
    };
    Ok(res)
}

/// 获取朗读状态
///
/// returns Result<i32, Error>
///     1: 版本不匹配
///     2: ZDSR没有运行
///     3: 正在朗读
///     4: 没有朗读
///
/// # examples
///
/// ```
/// use zdsr_api::get_speak_state;
/// get_speak_state().unwrap();
/// ```
pub fn get_speak_state() -> Result<i32, Error> {
    let Some(lib) = LIB.get() else {
        return Err(Error::new(
            ErrorKind::Other,
            "Can't find or init zdsr library.",
        ));
    };
    let res = unsafe {
        let func: Symbol<unsafe extern "C" fn() -> i32> = lib.get(b"GetSpeakState\0").unwrap();
        func()
    };
    Ok(res)
}

/// 停止朗读
///
/// returns: Result<(), Error>
///
/// # examples
///
/// ```
/// use zdsr_api::stop_speak;
/// stop_speak().unwrap();
/// ```
pub fn stop_speak() -> Result<(), Error> {
    let Some(lib) = LIB.get() else {
        return Err(Error::new(
            ErrorKind::Other,
            "Can't find or init zdsr library.",
        ));
    };
    let res = unsafe {
        let func: Symbol<unsafe extern "C" fn()> = lib.get(b"StopSpeak\0").unwrap();
        func()
    };
    Ok(res)
}

#[cfg(test)]
mod test_zdsr {
    use crate::{get_speak_state, init_tts, speak, stop_speak};

    #[test]
    fn main() {
        assert_eq!(0, init_tts(0, std::ptr::null(), 0).unwrap());
        assert_eq!(0, speak([65u16, 66, 67].as_ptr(), 0).unwrap());
        assert_eq!(3, get_speak_state().unwrap());
        stop_speak().unwrap();
    }
}