//! Audio settings persistence
//!
//! Stores user preferences for audio output device, exclusive mode, and DAC passthrough.

use crate::audio::{AlsaPlugin, AudioBackendType};
use rusqlite::{Connection, params};
use serde::{Deserialize, Serialize};
use std::sync::{Arc, Mutex};

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct AudioSettings {
    pub output_device: Option<String>,  // None = system default
    pub exclusive_mode: bool,
    pub dac_passthrough: bool,
    pub preferred_sample_rate: Option<u32>,  // None = auto
    pub backend_type: Option<AudioBackendType>,  // None = auto-detect
    pub alsa_plugin: Option<AlsaPlugin>,  // Only used when backend is ALSA
    pub alsa_hardware_volume: bool,  // Use ALSA mixer for volume (only with hw: devices)
    /// When true, uncached tracks start playing via streaming instead of waiting for full download
    pub stream_first_track: bool,
    /// Initial buffer size in seconds before starting streaming playback (1-10, default 3)
    pub stream_buffer_seconds: u8,
}

impl Default for AudioSettings {
    fn default() -> Self {
        Self {
            output_device: None,
            exclusive_mode: false,
            dac_passthrough: false,
            preferred_sample_rate: None,
            backend_type: None,  // Auto-detect (PipeWire if available, else ALSA)
            alsa_plugin: Some(AlsaPlugin::Hw),  // Default to hw (bit-perfect)
            alsa_hardware_volume: false,  // Disabled by default (maximum compatibility)
            stream_first_track: false,  // Disabled by default (current behavior)
            stream_buffer_seconds: 3,  // 3 seconds initial buffer
        }
    }
}

pub struct AudioSettingsStore {
    conn: Connection,
}

impl AudioSettingsStore {
    pub fn new() -> Result<Self, String> {
        let data_dir = dirs::data_dir()
            .ok_or("Could not determine data directory")?
            .join("qbz");

        std::fs::create_dir_all(&data_dir)
            .map_err(|e| format!("Failed to create data directory: {}", e))?;

        let db_path = data_dir.join("audio_settings.db");
        let conn = Connection::open(&db_path)
            .map_err(|e| format!("Failed to open audio settings database: {}", e))?;

        conn.execute_batch(
            "CREATE TABLE IF NOT EXISTS audio_settings (
                id INTEGER PRIMARY KEY CHECK (id = 1),
                output_device TEXT,
                exclusive_mode INTEGER NOT NULL DEFAULT 0,
                dac_passthrough INTEGER NOT NULL DEFAULT 0,
                preferred_sample_rate INTEGER,
                backend_type TEXT,
                alsa_plugin TEXT,
                alsa_hardware_volume INTEGER NOT NULL DEFAULT 0,
                stream_first_track INTEGER NOT NULL DEFAULT 0,
                stream_buffer_seconds INTEGER NOT NULL DEFAULT 3
            );
            INSERT OR IGNORE INTO audio_settings (id, exclusive_mode, dac_passthrough)
            VALUES (1, 0, 0);"
        ).map_err(|e| format!("Failed to create audio settings table: {}", e))?;

        // Migration: Add new columns if they don't exist (for existing databases)
        let _ = conn.execute("ALTER TABLE audio_settings ADD COLUMN backend_type TEXT", []);
        let _ = conn.execute("ALTER TABLE audio_settings ADD COLUMN alsa_plugin TEXT", []);
        let _ = conn.execute("ALTER TABLE audio_settings ADD COLUMN alsa_hardware_volume INTEGER DEFAULT 0", []);
        let _ = conn.execute("ALTER TABLE audio_settings ADD COLUMN stream_first_track INTEGER DEFAULT 0", []);
        let _ = conn.execute("ALTER TABLE audio_settings ADD COLUMN stream_buffer_seconds INTEGER DEFAULT 3", []);

        Ok(Self { conn })
    }

    pub fn get_settings(&self) -> Result<AudioSettings, String> {
        self.conn
            .query_row(
                "SELECT output_device, exclusive_mode, dac_passthrough, preferred_sample_rate, backend_type, alsa_plugin, alsa_hardware_volume, stream_first_track, stream_buffer_seconds FROM audio_settings WHERE id = 1",
                [],
                |row| {
                    // Parse backend_type from JSON string
                    let backend_type: Option<AudioBackendType> = row
                        .get::<_, Option<String>>(4)?
                        .and_then(|s| serde_json::from_str(&s).ok());

                    // Parse alsa_plugin from JSON string
                    let alsa_plugin: Option<AlsaPlugin> = row
                        .get::<_, Option<String>>(5)?
                        .and_then(|s| serde_json::from_str(&s).ok());

                    Ok(AudioSettings {
                        output_device: row.get(0)?,
                        exclusive_mode: row.get::<_, i64>(1)? != 0,
                        dac_passthrough: row.get::<_, i64>(2)? != 0,
                        preferred_sample_rate: row.get(3)?,
                        backend_type,
                        alsa_plugin,
                        alsa_hardware_volume: row.get::<_, Option<i64>>(6)?.unwrap_or(0) != 0,
                        stream_first_track: row.get::<_, Option<i64>>(7)?.unwrap_or(0) != 0,
                        stream_buffer_seconds: row.get::<_, Option<i64>>(8)?.unwrap_or(3) as u8,
                    })
                },
            )
            .map_err(|e| format!("Failed to get audio settings: {}", e))
    }

    pub fn set_output_device(&self, device: Option<&str>) -> Result<(), String> {
        self.conn
            .execute(
                "UPDATE audio_settings SET output_device = ?1 WHERE id = 1",
                params![device],
            )
            .map_err(|e| format!("Failed to set output device: {}", e))?;
        Ok(())
    }

    pub fn set_exclusive_mode(&self, enabled: bool) -> Result<(), String> {
        self.conn
            .execute(
                "UPDATE audio_settings SET exclusive_mode = ?1 WHERE id = 1",
                params![enabled as i64],
            )
            .map_err(|e| format!("Failed to set exclusive mode: {}", e))?;
        Ok(())
    }

    pub fn set_dac_passthrough(&self, enabled: bool) -> Result<(), String> {
        self.conn
            .execute(
                "UPDATE audio_settings SET dac_passthrough = ?1 WHERE id = 1",
                params![enabled as i64],
            )
            .map_err(|e| format!("Failed to set DAC passthrough: {}", e))?;
        Ok(())
    }

    pub fn set_sample_rate(&self, rate: Option<u32>) -> Result<(), String> {
        self.conn
            .execute(
                "UPDATE audio_settings SET preferred_sample_rate = ?1 WHERE id = 1",
                params![rate.map(|r| r as i64)],
            )
            .map_err(|e| format!("Failed to set sample rate: {}", e))?;
        Ok(())
    }

    pub fn set_backend_type(&self, backend: Option<AudioBackendType>) -> Result<(), String> {
        let backend_json = backend
            .map(|b| serde_json::to_string(&b))
            .transpose()
            .map_err(|e| format!("Failed to serialize backend type: {}", e))?;

        self.conn
            .execute(
                "UPDATE audio_settings SET backend_type = ?1 WHERE id = 1",
                params![backend_json],
            )
            .map_err(|e| format!("Failed to set backend type: {}", e))?;
        Ok(())
    }

    pub fn set_alsa_plugin(&self, plugin: Option<AlsaPlugin>) -> Result<(), String> {
        let plugin_json = plugin
            .map(|p| serde_json::to_string(&p))
            .transpose()
            .map_err(|e| format!("Failed to serialize ALSA plugin: {}", e))?;

        self.conn
            .execute(
                "UPDATE audio_settings SET alsa_plugin = ?1 WHERE id = 1",
                params![plugin_json],
            )
            .map_err(|e| format!("Failed to set ALSA plugin: {}", e))?;
        Ok(())
    }

    pub fn set_alsa_hardware_volume(&self, enabled: bool) -> Result<(), String> {
        self.conn
            .execute(
                "UPDATE audio_settings SET alsa_hardware_volume = ?1 WHERE id = 1",
                params![enabled as i64],
            )
            .map_err(|e| format!("Failed to set ALSA hardware volume: {}", e))?;
        Ok(())
    }

    pub fn set_stream_first_track(&self, enabled: bool) -> Result<(), String> {
        self.conn
            .execute(
                "UPDATE audio_settings SET stream_first_track = ?1 WHERE id = 1",
                params![enabled as i64],
            )
            .map_err(|e| format!("Failed to set stream first track: {}", e))?;
        Ok(())
    }

    pub fn set_stream_buffer_seconds(&self, seconds: u8) -> Result<(), String> {
        // Clamp to valid range 1-10
        let clamped = seconds.clamp(1, 10);
        self.conn
            .execute(
                "UPDATE audio_settings SET stream_buffer_seconds = ?1 WHERE id = 1",
                params![clamped as i64],
            )
            .map_err(|e| format!("Failed to set stream buffer seconds: {}", e))?;
        Ok(())
    }
}

/// Thread-safe wrapper
pub struct AudioSettingsState {
    pub store: Arc<Mutex<AudioSettingsStore>>,
}

impl AudioSettingsState {
    pub fn new() -> Result<Self, String> {
        Ok(Self {
            store: Arc::new(Mutex::new(AudioSettingsStore::new()?)),
        })
    }
}

// Tauri commands
#[tauri::command]
pub fn get_audio_settings(
    state: tauri::State<'_, AudioSettingsState>,
) -> Result<AudioSettings, String> {
    let store = state.store.lock().map_err(|e| format!("Lock error: {}", e))?;
    store.get_settings()
}

#[tauri::command]
pub fn set_audio_output_device(
    state: tauri::State<'_, AudioSettingsState>,
    device: Option<String>,
) -> Result<(), String> {
    let store = state.store.lock().map_err(|e| format!("Lock error: {}", e))?;
    store.set_output_device(device.as_deref())
}

#[tauri::command]
pub fn set_audio_exclusive_mode(
    state: tauri::State<'_, AudioSettingsState>,
    enabled: bool,
) -> Result<(), String> {
    let store = state.store.lock().map_err(|e| format!("Lock error: {}", e))?;
    store.set_exclusive_mode(enabled)
}

#[tauri::command]
pub fn set_audio_dac_passthrough(
    state: tauri::State<'_, AudioSettingsState>,
    enabled: bool,
) -> Result<(), String> {
    let store = state.store.lock().map_err(|e| format!("Lock error: {}", e))?;
    store.set_dac_passthrough(enabled)
}

#[tauri::command]
pub fn set_audio_sample_rate(
    state: tauri::State<'_, AudioSettingsState>,
    rate: Option<u32>,
) -> Result<(), String> {
    let store = state.store.lock().map_err(|e| format!("Lock error: {}", e))?;
    store.set_sample_rate(rate)
}

#[tauri::command]
pub fn set_audio_backend_type(
    state: tauri::State<'_, AudioSettingsState>,
    backend_type: Option<AudioBackendType>,
) -> Result<(), String> {
    let store = state.store.lock().map_err(|e| format!("Lock error: {}", e))?;
    store.set_backend_type(backend_type)
}

#[tauri::command]
pub fn set_audio_alsa_plugin(
    state: tauri::State<'_, AudioSettingsState>,
    plugin: Option<AlsaPlugin>,
) -> Result<(), String> {
    let store = state.store.lock().map_err(|e| format!("Lock error: {}", e))?;
    store.set_alsa_plugin(plugin)
}

#[tauri::command]
pub fn set_audio_alsa_hardware_volume(
    state: tauri::State<'_, AudioSettingsState>,
    enabled: bool,
) -> Result<(), String> {
    let store = state.store.lock().map_err(|e| format!("Lock error: {}", e))?;
    store.set_alsa_hardware_volume(enabled)
}

#[tauri::command]
pub fn set_audio_stream_first_track(
    state: tauri::State<'_, AudioSettingsState>,
    enabled: bool,
) -> Result<(), String> {
    let store = state.store.lock().map_err(|e| format!("Lock error: {}", e))?;
    store.set_stream_first_track(enabled)
}

#[tauri::command]
pub fn set_audio_stream_buffer_seconds(
    state: tauri::State<'_, AudioSettingsState>,
    seconds: u8,
) -> Result<(), String> {
    let store = state.store.lock().map_err(|e| format!("Lock error: {}", e))?;
    store.set_stream_buffer_seconds(seconds)
}