// Package database provides database factory for creating the appropriate backend.
package database

import (
	"fmt"
	"os"
	"path/filepath"

	"tyto/internal/config"
)

// New creates a new database connection based on configuration.
func New(cfg *config.DatabaseConfig) (Database, error) {
	retention := DefaultRetentionConfig()

	// Override retention from config if provided
	if cfg.Retention.RawRetention > 0 {
		retention.RawRetention = cfg.Retention.RawRetention
	}
	if cfg.Retention.OneMinuteRetention > 0 {
		retention.OneMinuteRetention = cfg.Retention.OneMinuteRetention
	}
	if cfg.Retention.FiveMinuteRetention > 0 {
		retention.FiveMinuteRetention = cfg.Retention.FiveMinuteRetention
	}
	if cfg.Retention.HourlyRetention > 0 {
		retention.HourlyRetention = cfg.Retention.HourlyRetention
	}

	switch cfg.Type {
	case "sqlite", "":
		return newSQLiteFromConfig(cfg, retention)
	case "postgres", "postgresql":
		return newPostgresFromConfig(cfg, retention)
	default:
		return nil, fmt.Errorf("unsupported database type: %s", cfg.Type)
	}
}

func newSQLiteFromConfig(cfg *config.DatabaseConfig, retention RetentionConfig) (*SQLiteDB, error) {
	path := cfg.Path
	if path == "" {
		path = "tyto.db"
	}

	// Ensure directory exists
	dir := filepath.Dir(path)
	if dir != "" && dir != "." {
		if err := os.MkdirAll(dir, 0755); err != nil {
			return nil, fmt.Errorf("create database directory: %w", err)
		}
	}

	db, err := NewSQLiteDB(path, retention)
	if err != nil {
		return nil, err
	}

	// Run migrations
	if err := db.Migrate(); err != nil {
		db.Close()
		return nil, fmt.Errorf("migrate: %w", err)
	}

	return db, nil
}

func newPostgresFromConfig(cfg *config.DatabaseConfig, retention RetentionConfig) (*PostgresDB, error) {
	connStr := cfg.ConnectionString
	if connStr == "" {
		// Build connection string from individual fields
		connStr = fmt.Sprintf(
			"host=%s port=%d user=%s password=%s dbname=%s sslmode=%s",
			cfg.Host, cfg.Port, cfg.User, cfg.Password, cfg.Database, cfg.SSLMode,
		)
	}

	db, err := NewPostgresDB(connStr, retention)
	if err != nil {
		return nil, err
	}

	// Run migrations
	if err := db.Migrate(); err != nil {
		db.Close()
		return nil, fmt.Errorf("migrate: %w", err)
	}

	return db, nil
}