#![deny(trivial_casts, trivial_numeric_casts,
        unsafe_code, unstable_features,
        unused_import_braces, unused_qualifications)]

/// This crate provides a native and easy way to read and write
/// *Grand Theft Auto: Vice City* settings file (gta_vc.set).
///
/// # Usage
/// This crate is on crates.io and can be used by adding gta_vc_settings to
/// your dependencies in your project's Cargo.toml.
///
/// ```toml
/// [dependencies]
/// gta_vc_settings = "0.1"
/// ```
///
/// and this to your crate root:
///
/// ```
/// extern crate gta_vc_settings;
/// ```
///
/// # Example: read a settings file.
/// ```
/// use gta_vc_settings::GtaVcSettings;
///
/// let mut settings = GtaVcSettings::new();
/// settings.read("./tests/gta_vc.set");
/// ```

/**
 *    Copyright (C) 2016 Jean Piere Dudey
 *
 *    This program is free software: you can redistribute it and/or modify
 *    it under the terms of the GNU General Public License as published by
 *    the Free Software Foundation, either version 3 of the License, or
 *    (at your option) any later version.
 *
 *    This program is distributed in the hope that it will be useful,
 *    but WITHOUT ANY WARRANTY; without even the implied warranty of
 *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *    GNU General Public License for more details.
 *
 *    You should have received a copy of the GNU General Public License
 *    along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

extern crate byteorder;

use byteorder::{ReadBytesExt, WriteBytesExt, LittleEndian};
use std::fs::File;
use std::io::{Read, Write, Seek, SeekFrom};
use std::path::Path;
use std::str;
use std::io;

/// Enum representing result returned by `GtaVcSettings` functions.
#[derive(Debug)]
pub enum SettingsResult {
    /// Returned when the operation was completed succesfully.
    Ok,

    /// Returned when an I/O operation was errored.
    IoError(io::Error),

    /// Returned if the file is not valid yet.
    NotValidYet
}

/// Struct representing a settings file.
pub struct GtaVcSettings {
    /// Defaults to 3
    pub total_sections: u32,

    /// Primary controls, Secondary controls, Tertiary controls and Quaternary
    /// controls. 
    pub controls: [u8; 352],

    /// Some strings generated by the game.
    pub strings: [u8; 51],

    /// Unknown byte.
    pub unknown: u8,

    /// Mouse sensitivity.
    pub mouse_sensitivity: u32,

    /// Invert mouse vertically.
    /// (0 = on, 1 = off)
    pub mouse_invert_y: u8,

    /// Mouse controlled steering.
    /// (0 = on, 1 = off)
    pub steer_with_mouse: u8,

    /// SFX volume.
    /// (1 = lowest setting, 65 = highest setting, 49 = default setting)
    pub sfx_volume: u8,

    /// Music volume.
    /// (1 = lowest setting, 65 = highest setting, 49 = default setting)
    pub music_volume: u8,

    /// MP3 volume boost.
    /// (1 = lowest setting, 65 = highest setting, 0 = default setting)
    pub mp3_volume_boost: u8,

    /// Radio station.
    /// See http://www.gtamodding.com/wiki/List_of_radio_stations_(VC) for
    /// more information.
    pub current_radio: u8,

    /// Speakers configuration.
    /// (0 = 2 speakers, 1 = headphones, 2 = more than 2 speakers)
    pub speakers_configuration: u8,

    /// Audio hardware.
    pub audio_hardware: u8,

    /// Dynamic acoustic modeling.
    /// (0 = off, 1 = on)
    pub dynamic_acoustic_mode: u8,

    /// Brightness.
    /// (6 = lowest setting, 384 = highest setting, 256 = default)
    pub brightness: u16,

    /// Draw distance.
    /// (0.925 = lowest setting, 1.80 = highest setting, 1.20 = default setting)
    pub draw_distance: f32,

    /// Subtitles.
    /// (0 = off, 1 = on)
    pub subtitles: u8,

    /// Wide screen.
    /// (0 = off, 1 = on)
    pub widescreen: u8,

    /// Frame limiter.
    /// (0 = off, 1 = on)
    pub frame_limiter: u8,

    /// Screen resolution.
    pub video_mode: u8,

    /// Skin name without file extension with null terminator
    /// (default skin = $$""\0)
    pub skin_path: [u8; 256],

    /// Controls.
    /// (0 = standard, 1 = classic)
    pub standard_controls: u8,

    /// Language.
    /// (0 = English, 1 = French, 2 = German, 3 = Italian, 4 = Spanish)
    pub current_language: u8,

    /// HUD mode.
    /// (0 = off, 1 = on)
    pub hud_mode: u8,

    /// Radar mode.
    /// (0 = map & blips, 1 = blips only, 2 = off)
    pub radar_mode: u8,

    /// Map legend.
    pub map_legend: u8,
}

const NOT_VALID_STR: &'static str = "THIS FILE IS NOT VALID YET";

impl GtaVcSettings {
    /// Creates a GtaVcSettings with default data.
    ///
    /// # Examples
    /// ```
    /// use gta_vc_settings::GtaVcSettings;
    ///
    /// let settings = GtaVcSettings::new();
    /// assert_eq!(settings.total_sections, 3);
    /// ```
    pub fn new() -> GtaVcSettings {
        // TODO: Add more default values.
        GtaVcSettings {
            total_sections: 3,
            controls: [0; 352],
            strings: [0; 51],
            unknown: 0,
            mouse_sensitivity: 0,
            mouse_invert_y: 1,
            steer_with_mouse: 1,
            sfx_volume: 49,
            music_volume: 49,
            mp3_volume_boost: 0,
            current_radio: 0,
            speakers_configuration: 0,
            audio_hardware: 0,
            dynamic_acoustic_mode: 0,
            brightness: 256,
            draw_distance: 1.20,
            subtitles: 0,
            widescreen: 0,
            frame_limiter: 0,
            video_mode: 0,
            skin_path: [0; 256],
            standard_controls: 0,
            current_language: 0,
            hud_mode: 0,
            radar_mode: 0,
            map_legend: 0
        }
    }

    /// Opens and reads a GTA: Vice City settings file and returns a
    /// GtaVcSettings with it's data.
    ///
    /// # Examples
    /// ```
    /// use gta_vc_settings::GtaVcSettings;
    ///
    /// let mut settings = GtaVcSettings::new();
    /// settings.read("./tests/gta_vc.set");
    ///
    /// assert_eq!(settings.total_sections, 3);
    /// ```
    pub fn read<P: AsRef<Path>>(&mut self, path: P) -> SettingsResult {
        let mut file = match File::open(path) {
            Ok(mut file) => {
                let mut buffer = [0; 29];
                file.read(&mut buffer).unwrap();

                let bufstr = str::from_utf8(&buffer);
                let is_not_valid = bufstr == Ok(NOT_VALID_STR);

                if is_not_valid {
                    return SettingsResult::NotValidYet
                }

                file
            },
            Err(err) => return SettingsResult::IoError(err)
        };

        file.seek(SeekFrom::Start(0)).unwrap();
        self.total_sections = file.read_u32::<LittleEndian>().unwrap();

        if self.total_sections >= 3 {
            file.read(&mut self.controls).unwrap();
            file.read(&mut self.strings).unwrap();

            self.unknown = file.read_u8().unwrap();
            self.mouse_sensitivity = file.read_u32::<LittleEndian>().unwrap();
            self.mouse_invert_y = file.read_u8().unwrap();
            self.steer_with_mouse = file.read_u8().unwrap();
            self.sfx_volume = file.read_u8().unwrap();
            self.music_volume = file.read_u8().unwrap();
            self.mp3_volume_boost = file.read_u8().unwrap();
            self.current_radio = file.read_u8().unwrap();
            self.speakers_configuration = file.read_u8().unwrap();
            self.audio_hardware = file.read_u8().unwrap();
            self.dynamic_acoustic_mode = file.read_u8().unwrap();
            self.brightness = file.read_u16::<LittleEndian>().unwrap();
            self.draw_distance = file.read_f32::<LittleEndian>().unwrap();
            self.subtitles = file.read_u8().unwrap();
            self.widescreen = file.read_u8().unwrap();
            self.frame_limiter = file.read_u8().unwrap();
            self.video_mode = file.read_u8().unwrap();

            file.read(&mut self.skin_path).unwrap();

            self.standard_controls = file.read_u8().unwrap();
            self.current_language = file.read_u8().unwrap();
            self.hud_mode = file.read_u8().unwrap();
            self.radar_mode = file.read_u8().unwrap();
            self.map_legend = file.read_u8().unwrap();
        }

        SettingsResult::Ok
    }

    /// Writes a GTA: Vice City settings file to the filesystem.
    ///
    /// # Examples
    /// ```
    /// use gta_vc_settings::GtaVcSettings;
    ///
    /// let settings = GtaVcSettings::new();
    ///
    /// settings.write("./ouput.set");
    /// ```
    pub fn write<P: AsRef<Path>>(&self, path: P) -> SettingsResult {
        let mut file = match File::create(path) {
            Ok(f) => f,
            Err(err) => return SettingsResult::IoError(err)
        };

        file.write_u32::<LittleEndian>(self.total_sections).unwrap();

        file.write(&self.controls).unwrap();
        file.write(&self.strings).unwrap();

        file.write_u8(self.unknown).unwrap();
        file.write_u32::<LittleEndian>(self.mouse_sensitivity).unwrap();
        file.write_u8(self.mouse_invert_y).unwrap();
        file.write_u8(self.steer_with_mouse).unwrap();
        file.write_u8(self.sfx_volume).unwrap();
        file.write_u8(self.music_volume).unwrap();
        file.write_u8(self.mp3_volume_boost).unwrap();
        file.write_u8(self.current_radio).unwrap();
        file.write_u8(self.speakers_configuration).unwrap();
        file.write_u8(self.audio_hardware).unwrap();
        file.write_u8(self.dynamic_acoustic_mode).unwrap();
        file.write_u16::<LittleEndian>(self.brightness).unwrap();
        file.write_f32::<LittleEndian>(self.draw_distance).unwrap();
        file.write_u8(self.subtitles).unwrap();
        file.write_u8(self.widescreen).unwrap();
        file.write_u8(self.frame_limiter).unwrap();
        file.write_u8(self.video_mode).unwrap();

        file.write(&self.skin_path).unwrap();

        file.write_u8(self.standard_controls).unwrap();
        file.write_u8(self.current_language).unwrap();
        file.write_u8(self.hud_mode).unwrap();
        file.write_u8(self.radar_mode).unwrap();
        file.write_u8(self.map_legend).unwrap();
        
        SettingsResult::Ok
    }
}