use bevy::prelude::*;
use std::collections::HashMap;
use std::env;

pub const SCOPE_SEPARATOR: &str = "$";

pub const TOKEN_EQUALS: &str = "==";
pub const TOKEN_EQUALS_NOT: &str = "!=";
pub const TOKEN_GREATER_THAN: &str = ">";
pub const TOKEN_LESS_THAN: &str = "<";
pub const TOKEN_GREATER_EQUALS: &str = ">=";
pub const TOKEN_LESS_EQUALS: &str = "<=";
pub const TOKEN_NEGATE: &str = "~";

pub const DEFAULT_CHAT_SPEED: f32 = 10.0;

#[derive(Resource)]
pub struct Settings {
    pub dev_mode: bool,
    pub god_mode: bool,
    pub version: String,
    pub mute_sfx: bool,
    pub mute_music: bool,
    pub volume_sfx: u8,
    pub volume_music: u8,
    pub mouse_sensitivity: f32,
    pub fov: f32,
    pub fov_highspeed: f32,
    pub zoom_fov: f32,
    pub zoom_sensitivity_factor: f32,
    pub font_size_hud: f32,
    pub font_size_conversations: f32,
    pub font_size_choices: f32,
    pub font_size_console: f32,
    pub hud_color: Color,
    pub hud_color_console: Color,
    pub hud_color_console_warn: Color,
    pub hud_color_console_system: Color,
    pub hud_color_alert: Color,
    pub hud_color_subtitles: Color,
    pub hud_color_choices: Color,
    pub chat_speed: f32,
    pub hud_active: bool,
    pub is_zooming: bool,
    pub third_person: bool,
    pub rotation_stabilizer_active: bool,
    pub key_selectobject: MouseButton,
    pub key_zoom: MouseButton,
    pub key_togglehud: KeyCode,
    pub key_exit: KeyCode,
    pub key_restart: KeyCode,
    pub key_fullscreen: KeyCode,
    pub key_help: KeyCode,
    pub key_forward: KeyCode,
    pub key_back: KeyCode,
    pub key_left: KeyCode,
    pub key_right: KeyCode,
    pub key_up: KeyCode,
    pub key_down: KeyCode,
    pub key_run: KeyCode,
    pub key_stop: KeyCode,
    pub key_interact: KeyCode,
    pub key_vehicle: KeyCode,
    pub key_camera: KeyCode,
    pub key_rotate: KeyCode,
    pub key_rotation_stabilizer: KeyCode,
    pub key_mouseup: KeyCode,
    pub key_mousedown: KeyCode,
    pub key_mouseleft: KeyCode,
    pub key_mouseright: KeyCode,
    pub key_rotateleft: KeyCode,
    pub key_rotateright: KeyCode,
    pub key_reply1: KeyCode,
    pub key_reply2: KeyCode,
    pub key_reply3: KeyCode,
    pub key_reply4: KeyCode,
    pub key_reply5: KeyCode,
    pub key_reply6: KeyCode,
    pub key_reply7: KeyCode,
    pub key_reply8: KeyCode,
    pub key_reply9: KeyCode,
    pub key_reply10: KeyCode,
    pub key_cheat_god_mode: KeyCode,
    pub key_cheat_stop: KeyCode,
    pub key_cheat_speed: KeyCode,
    pub key_cheat_speed_backward: KeyCode,
    pub key_cheat_teleport: KeyCode,
    pub key_cheat_pizza: KeyCode,
    pub key_cheat_farview1: KeyCode,
    pub key_cheat_farview2: KeyCode,
    pub key_cheat_adrenaline_zero: KeyCode,
    pub key_cheat_adrenaline_mid: KeyCode,
    pub key_cheat_adrenaline_max: KeyCode,
    pub key_cheat_die: KeyCode,
}

impl Default for Settings {
    fn default() -> Self {
        let dev_mode;

        let default_mute_sfx = false;
        let default_mute_music;
        if let Ok(_) = env::var("CARGO") {
            // Mute audio by default when run through `cargo`
            default_mute_music = cfg!(debug_assertions);

            // Enable dev mode when running `cargo run` without `--release`
            dev_mode = cfg!(debug_assertions);
        }
        else {
            default_mute_music = false;
            dev_mode = false;
        }
        let version = if let Some(version) = option_env!("CARGO_PKG_VERSION") {
            version.to_string()
        } else {
            "13.37".to_string()
        };

        Settings {
            dev_mode,
            god_mode: false,
            version,
            mute_sfx: default_mute_sfx,
            mute_music: default_mute_music,
            volume_sfx: 100,
            volume_music: 100,
            mouse_sensitivity: 0.4,
            fov: 50.0,
            fov_highspeed: 25.0,
            zoom_fov: 15.0,
            zoom_sensitivity_factor: 0.25,
            font_size_hud: 24.0,
            font_size_conversations: 32.0,
            font_size_choices: 28.0,
            font_size_console: 20.0,
            hud_color: Color::rgb(0.1, 0.5, 0.1),
            hud_color_console: Color::rgb(0.1, 0.5, 0.1),
            hud_color_console_warn: Color::rgb(1.0, 0.3, 0.3),
            hud_color_console_system: Color::rgb(0.5, 0.5, 0.5),
            hud_color_alert: Color::rgb(0.6, 0.094, 0.322),
            hud_color_subtitles: Color::rgb(0.8, 0.8, 0.8),
            hud_color_choices: Color::rgb(0.45, 0.45, 0.45),
            chat_speed: DEFAULT_CHAT_SPEED * if dev_mode { 2.5 } else { 1.0 },
            hud_active: false,
            is_zooming: false,
            third_person: false,
            rotation_stabilizer_active: true,
            key_selectobject: MouseButton::Left,
            key_zoom: MouseButton::Right,
            key_togglehud: KeyCode::Tab,
            key_exit: KeyCode::Escape,
            key_restart: KeyCode::F7,
            key_fullscreen: KeyCode::F11,
            key_help: KeyCode::F1,
            key_forward: KeyCode::KeyW,
            key_back: KeyCode::KeyS,
            key_left: KeyCode::KeyA,
            key_right: KeyCode::KeyD,
            key_up: KeyCode::ShiftLeft,
            key_down: KeyCode::ControlLeft,
            key_run: KeyCode::KeyR,
            key_stop: KeyCode::Space,
            key_interact: KeyCode::KeyE,
            key_vehicle: KeyCode::KeyQ,
            key_camera: KeyCode::KeyF,
            key_rotate: KeyCode::KeyR,
            key_rotation_stabilizer: KeyCode::KeyY,
            key_mouseup: KeyCode::KeyI,
            key_mousedown: KeyCode::KeyK,
            key_mouseleft: KeyCode::KeyJ,
            key_mouseright: KeyCode::KeyL,
            key_rotateleft: KeyCode::KeyU,
            key_rotateright: KeyCode::KeyO,
            key_reply1: KeyCode::Digit1,
            key_reply2: KeyCode::Digit2,
            key_reply3: KeyCode::Digit3,
            key_reply4: KeyCode::Digit4,
            key_reply5: KeyCode::Digit5,
            key_reply6: KeyCode::Digit6,
            key_reply7: KeyCode::Digit7,
            key_reply8: KeyCode::Digit8,
            key_reply9: KeyCode::Digit9,
            key_reply10: KeyCode::Digit0,
            key_cheat_god_mode: KeyCode::KeyG,
            key_cheat_stop: KeyCode::KeyC,
            key_cheat_speed: KeyCode::KeyV,
            key_cheat_speed_backward: KeyCode::KeyB,
            key_cheat_teleport: KeyCode::KeyX,
            key_cheat_pizza: KeyCode::F9,
            key_cheat_farview1: KeyCode::F10,
            key_cheat_farview2: KeyCode::F12,
            key_cheat_adrenaline_zero: KeyCode::F5,
            key_cheat_adrenaline_mid: KeyCode::F6,
            key_cheat_adrenaline_max: KeyCode::F8,
            key_cheat_die: KeyCode::KeyZ,
        }
    }
}

impl Settings {
    #[allow(dead_code)]
    pub fn reset(&mut self) {
        println!("Resetting settings!");
        *self = Self::default();
    }

    pub fn reset_player_settings(&mut self) {
        println!("Resetting player settings!");
        let default = Self::default();
        self.rotation_stabilizer_active = default.rotation_stabilizer_active;
        self.third_person = default.third_person;
        self.is_zooming = default.is_zooming;
    }

    pub fn get_reply_keys(&self) -> [KeyCode; 10] {
        return [
            self.key_reply1,
            self.key_reply2,
            self.key_reply3,
            self.key_reply4,
            self.key_reply5,
            self.key_reply6,
            self.key_reply7,
            self.key_reply8,
            self.key_reply9,
            self.key_reply10,
        ];
    }
}

#[derive(Resource)]
pub struct GameVars {
    pub db: HashMap<String, String>,
}

impl Default for GameVars {
    fn default() -> Self {
        Self {
            db: HashMap::new(),
        }
    }
}

impl GameVars {
    #[allow(dead_code)]
    pub fn get(&self, key: &str) -> Option<String> {
        if let Some(value) = self.db.get(key) {
            return Some(value.clone());
        }
        return None;
    }

    #[allow(dead_code)]
    pub fn getf(&self, key: &str) -> Option<f64> {
        if let Some(value) = self.db.get(key) {
            if let Ok(float) = value.parse::<f64>() {
                return Some(float);
            }
        }
        return None;
    }

    pub fn getb(&self, key: &str) -> bool {
        if let Some(value) = self.db.get(key) {
            return Self::evaluate_str_as_bool(value);
        }
        return false;
    }

    pub fn evaluate_str_as_bool(string: &str) -> bool {
        return string != "0";
    }

    // This method ensures that the variable name contains a scope separator,
    // and if a scope is missing, it prefixes the fallback scope.
    // Should NOT be used on non-variable values, like plain strings.
    //
    // Some examples, assuming fallback_scope="Clippy", SCOPE_SEPARATOR="$":
    //
    // "" -> "clippy$"
    // "foo" -> "clippy$foo"
    // "FOO" -> "clippy$foo"
    // "$foo" -> "clippy$foo"
    // "$$foo" -> "$$foo"
    // "PizzaClippy$foo" -> "pizzaclippy$foo" (unchanged)
    // "$foo$foo$foo$foo" -> "$foo$foo$foo$foo" (unchanged)
    pub fn normalize_varname(fallback_scope: &str, key: &str) -> String {
        let parts: Vec<&str> = key.split(SCOPE_SEPARATOR).collect();
        let key: String = if parts.len() == 1 {
            // we got a key like "foo", turn it into "<scope>$foo"
            fallback_scope.to_string() + SCOPE_SEPARATOR + key
        } else if parts.len() > 1 {
            // we got a key with at least one "$"
            // extract anything before the last "$":
            let scope_part: String = parts[0..parts.len() - 2].join(SCOPE_SEPARATOR);

            if scope_part.is_empty() {
                // we got a key like "$foo", just prefix the fallback scope
                fallback_scope.to_string() + key
            }
            else {
                // we got a key like "Ke$ha$foo" or "$$foo" (which is the convention for
                // global variables), leave the scope intact
                key.to_string()
            }
        } else {
            // we got an empty string. this is bad, but handle gracefully
            fallback_scope.to_string() + SCOPE_SEPARATOR
        };
        return key.to_lowercase();
    }

    pub fn set_in_scope(&mut self, fallback_scope: &str, key: &str, value: String) {
        let key = Self::normalize_varname(fallback_scope, key);
        self.db.insert(key, value);
    }

    pub fn evaluate_condition(&self, condition: &str, scope: &str) -> bool {
        let parts: Vec<&str> = condition.split(" ").collect();
        if parts.len() == 0 {
            // Got an empty string, this is always false.
            return false;
        } else if parts.len() == 1 {
            // Got something like "if $somevar:".
            // Check whether the variable evaluates to true.
            let part = parts[0];
            let (part, negate) = if part.starts_with(TOKEN_NEGATE) {
                (&part[1..], true)
            } else {
                (part, false)
            };
            if part.contains(SCOPE_SEPARATOR) {
                let part = Self::normalize_varname(scope, part);
                let value_bool = self.getb(part.as_str());
                return value_bool ^ negate;
            }
            else {
                return Self::evaluate_str_as_bool(part) ^ negate;
            }

        } else if parts.len() == 2 {
            // Got something like "if $something somethingelse"
            // Check whether the two are identical.
            let mut left: String = parts[0].to_string();
            if left.contains(SCOPE_SEPARATOR) {
                left = self
                    .get(Self::normalize_varname(scope, left.as_str()).as_str())
                    .unwrap_or("".to_string());
            }
            let mut right: String = parts[1].to_string();
            if right.contains(SCOPE_SEPARATOR) {
                right = self
                    .get(Self::normalize_varname(scope, right.as_str()).as_str())
                    .unwrap_or("".to_string());
            }
            return left == right;
        } else {
            // Got something like "if $something != somethingelse bla bla"
            let mut left: String = parts[0].to_string();
            if left.contains(SCOPE_SEPARATOR) {
                left = self
                    .get(Self::normalize_varname(scope, left.as_str()).as_str())
                    .unwrap_or("".to_string());
            }

            let mut right: String = parts[2..parts.len()].join(" ").to_string();
            if right.contains(SCOPE_SEPARATOR) {
                right = self
                    .get(Self::normalize_varname(scope, right.as_str()).as_str())
                    .unwrap_or("".to_string());
            }
            let floats = (left.parse::<f64>(), right.parse::<f64>());
            let operator: &str = parts[1];

            match operator {
                TOKEN_EQUALS => {
                    if let (Ok(left), Ok(right)) = floats {
                        return left == right;
                    }
                    return left == right;
                }
                TOKEN_EQUALS_NOT => {
                    if let (Ok(left), Ok(right)) = floats {
                        return left != right;
                    }
                    return left != right;
                }
                TOKEN_GREATER_THAN => {
                    if let (Ok(left), Ok(right)) = floats {
                        return left > right;
                    }
                    return false;
                }
                TOKEN_GREATER_EQUALS => {
                    if let (Ok(left), Ok(right)) = floats {
                        return left >= right;
                    }
                    return false;
                }
                TOKEN_LESS_THAN => {
                    if let (Ok(left), Ok(right)) = floats {
                        return left < right;
                    }
                    return false;
                }
                TOKEN_LESS_EQUALS => {
                    if let (Ok(left), Ok(right)) = floats {
                        return left <= right;
                    }
                    return false;
                }
                _ => {
                    error!("Unknown operator '{operator}' in if-condition!");
                    return false;
                }
            }
        }
    }
}