use config::{Config, ConfigError, Environment, File};
use serde::Deserialize;
use std::path::PathBuf;

#[derive(Debug, Clone, Deserialize)]
pub struct Settings {
    // Application settings
    pub app_name: String,
    pub port: u16,
    pub api_v1_prefix: String,
    
    // Database settings
    pub database_url: String,
    pub database_url_supabase: Option<String>,
    
    // Authentication
    pub secret_key: String,
    pub access_token_expire_minutes: u64,
    
    // Gacha probabilities (percentages)
    pub prob_normal: f64,
    pub prob_rare: f64,
    pub prob_super_rare: f64,
    pub prob_kira: f64,
    pub prob_unique: f64,
    
    // atproto settings
    pub atproto_pds_url: Option<String>,
    pub atproto_handle: Option<String>,
    
    // External data
    pub card_master_url: String,
    
    // File paths
    pub config_dir: PathBuf,
}

impl Settings {
    pub fn new() -> Result<Self, ConfigError> {
        let config_dir = dirs::home_dir()
            .unwrap_or_else(|| PathBuf::from("."))
            .join(".config")
            .join("syui")
            .join("ai")
            .join("card");

        // Ensure config directory exists
        if !config_dir.exists() {
            std::fs::create_dir_all(&config_dir)
                .map_err(|e| ConfigError::Message(format!("Failed to create config directory: {}", e)))?;
        }

        let mut builder = Config::builder()
            // Default values
            .set_default("app_name", "ai.card")?
            .set_default("port", 8000)?
            .set_default("api_v1_prefix", "/api/v1")?
            
            // Database defaults
            .set_default("database_url", format!("sqlite://{}?mode=rwc", config_dir.join("aicard.db").display()))?
            
            // Authentication defaults
            .set_default("secret_key", "your-secret-key-change-in-production")?
            .set_default("access_token_expire_minutes", 1440)? // 24 hours
            
            // Gacha probability defaults (matching Python implementation)
            .set_default("prob_normal", 99.789)?
            .set_default("prob_rare", 0.1)?
            .set_default("prob_super_rare", 0.01)?
            .set_default("prob_kira", 0.1)?
            .set_default("prob_unique", 0.0001)?
            
            // External data source
            .set_default("card_master_url", "https://git.syui.ai/ai/ai/raw/branch/main/ai.json")?;

        // Load from config file if it exists
        let config_file = config_dir.join("config.toml");
        if config_file.exists() {
            builder = builder.add_source(File::from(config_file));
        }

        // Override with environment variables (AI_CARD_ prefix)
        builder = builder.add_source(Environment::with_prefix("AI_CARD").separator("_"));

        let mut settings: Settings = builder.build()?.try_deserialize()?;
        
        // Set the config directory path
        settings.config_dir = config_dir;

        Ok(settings)
    }

    /// Get the gacha configuration for the gacha service
    pub fn gacha_config(&self) -> GachaConfig {
        GachaConfig {
            prob_normal: self.prob_normal,
            prob_rare: self.prob_rare,
            prob_super_rare: self.prob_super_rare,
            prob_kira: self.prob_kira,
            prob_unique: self.prob_unique,
        }
    }
}

#[derive(Debug, Clone)]
pub struct GachaConfig {
    pub prob_normal: f64,
    pub prob_rare: f64,
    pub prob_super_rare: f64,
    pub prob_kira: f64,
    pub prob_unique: f64,
}

impl GachaConfig {
    /// Calculate cumulative probabilities for rarity determination
    pub fn cumulative_probabilities(&self, is_paid: bool) -> Vec<(f64, crate::models::CardRarity)> {
        let multiplier = if is_paid { 2.0 } else { 1.0 };
        
        vec![
            (self.prob_unique * multiplier, crate::models::CardRarity::Unique),
            (self.prob_kira * multiplier, crate::models::CardRarity::Kira),
            (self.prob_super_rare * multiplier, crate::models::CardRarity::SuperRare),
            (self.prob_rare * multiplier, crate::models::CardRarity::Rare),
            (self.prob_normal, crate::models::CardRarity::Normal),
        ]
    }
}