package config

import (
	"database/sql"
	"fmt"
	"jiggablend/internal/database"
	"log"
	"os"
	"strconv"
)

// Config keys stored in database
const (
	KeyGoogleClientID       = "google_client_id"
	KeyGoogleClientSecret   = "google_client_secret"
	KeyGoogleRedirectURL    = "google_redirect_url"
	KeyDiscordClientID      = "discord_client_id"
	KeyDiscordClientSecret  = "discord_client_secret"
	KeyDiscordRedirectURL   = "discord_redirect_url"
	KeyEnableLocalAuth      = "enable_local_auth"
	KeyFixedAPIKey          = "fixed_api_key"
	KeyRegistrationEnabled  = "registration_enabled"
	KeyProductionMode       = "production_mode"
	KeyAllowedOrigins       = "allowed_origins"
)

// Config manages application configuration stored in the database
type Config struct {
	db *database.DB
}

// NewConfig creates a new config manager
func NewConfig(db *database.DB) *Config {
	return &Config{db: db}
}

// InitializeFromEnv loads configuration from environment variables on first run
// Environment variables take precedence only if the config key doesn't exist in the database
// This allows first-run setup via env vars, then subsequent runs use database values
func (c *Config) InitializeFromEnv() error {
	envMappings := []struct {
		envKey    string
		configKey string
		sensitive bool
	}{
		{"GOOGLE_CLIENT_ID", KeyGoogleClientID, false},
		{"GOOGLE_CLIENT_SECRET", KeyGoogleClientSecret, true},
		{"GOOGLE_REDIRECT_URL", KeyGoogleRedirectURL, false},
		{"DISCORD_CLIENT_ID", KeyDiscordClientID, false},
		{"DISCORD_CLIENT_SECRET", KeyDiscordClientSecret, true},
		{"DISCORD_REDIRECT_URL", KeyDiscordRedirectURL, false},
		{"ENABLE_LOCAL_AUTH", KeyEnableLocalAuth, false},
		{"FIXED_API_KEY", KeyFixedAPIKey, true},
		{"PRODUCTION", KeyProductionMode, false},
		{"ALLOWED_ORIGINS", KeyAllowedOrigins, false},
	}

	for _, mapping := range envMappings {
		envValue := os.Getenv(mapping.envKey)
		if envValue == "" {
			continue
		}

		// Check if config already exists in database
		exists, err := c.Exists(mapping.configKey)
		if err != nil {
			return fmt.Errorf("failed to check config %s: %w", mapping.configKey, err)
		}

		if !exists {
			// Store env value in database
			if err := c.Set(mapping.configKey, envValue); err != nil {
				return fmt.Errorf("failed to store config %s: %w", mapping.configKey, err)
			}
			if mapping.sensitive {
				log.Printf("Stored config from env: %s = [REDACTED]", mapping.configKey)
			} else {
				log.Printf("Stored config from env: %s = %s", mapping.configKey, envValue)
			}
		}
	}

	return nil
}

// Get retrieves a config value from the database
func (c *Config) Get(key string) (string, error) {
	var value string
	err := c.db.With(func(conn *sql.DB) error {
		return conn.QueryRow("SELECT value FROM settings WHERE key = ?", key).Scan(&value)
	})
	if err == sql.ErrNoRows {
		return "", nil
	}
	if err != nil {
		return "", fmt.Errorf("failed to get config %s: %w", key, err)
	}
	return value, nil
}

// GetWithDefault retrieves a config value or returns a default if not set
func (c *Config) GetWithDefault(key, defaultValue string) string {
	value, err := c.Get(key)
	if err != nil || value == "" {
		return defaultValue
	}
	return value
}

// GetBool retrieves a boolean config value
func (c *Config) GetBool(key string) (bool, error) {
	value, err := c.Get(key)
	if err != nil {
		return false, err
	}
	return value == "true" || value == "1", nil
}

// GetBoolWithDefault retrieves a boolean config value or returns a default
func (c *Config) GetBoolWithDefault(key string, defaultValue bool) bool {
	value, err := c.GetBool(key)
	if err != nil {
		return defaultValue
	}
	// If the key doesn't exist, Get returns empty string which becomes false
	// Check if key exists to distinguish between "false" and "not set"
	exists, _ := c.Exists(key)
	if !exists {
		return defaultValue
	}
	return value
}

// GetInt retrieves an integer config value
func (c *Config) GetInt(key string) (int, error) {
	value, err := c.Get(key)
	if err != nil {
		return 0, err
	}
	if value == "" {
		return 0, nil
	}
	return strconv.Atoi(value)
}

// GetIntWithDefault retrieves an integer config value or returns a default
func (c *Config) GetIntWithDefault(key string, defaultValue int) int {
	value, err := c.GetInt(key)
	if err != nil {
		return defaultValue
	}
	exists, _ := c.Exists(key)
	if !exists {
		return defaultValue
	}
	return value
}

// Set stores a config value in the database
func (c *Config) Set(key, value string) error {
	// Use upsert pattern
	exists, err := c.Exists(key)
	if err != nil {
		return err
	}

	err = c.db.With(func(conn *sql.DB) error {
	if exists {
			_, err = conn.Exec(
			"UPDATE settings SET value = ?, updated_at = CURRENT_TIMESTAMP WHERE key = ?",
			value, key,
		)
	} else {
			_, err = conn.Exec(
			"INSERT INTO settings (key, value, updated_at) VALUES (?, ?, CURRENT_TIMESTAMP)",
			key, value,
		)
	}
		return err
	})

	if err != nil {
		return fmt.Errorf("failed to set config %s: %w", key, err)
	}
	return nil
}

// SetBool stores a boolean config value
func (c *Config) SetBool(key string, value bool) error {
	strValue := "false"
	if value {
		strValue = "true"
	}
	return c.Set(key, strValue)
}

// SetInt stores an integer config value
func (c *Config) SetInt(key string, value int) error {
	return c.Set(key, strconv.Itoa(value))
}

// Delete removes a config value from the database
func (c *Config) Delete(key string) error {
	err := c.db.With(func(conn *sql.DB) error {
		_, err := conn.Exec("DELETE FROM settings WHERE key = ?", key)
		return err
	})
	if err != nil {
		return fmt.Errorf("failed to delete config %s: %w", key, err)
	}
	return nil
}

// Exists checks if a config key exists in the database
func (c *Config) Exists(key string) (bool, error) {
	var exists bool
	err := c.db.With(func(conn *sql.DB) error {
		return conn.QueryRow("SELECT EXISTS(SELECT 1 FROM settings WHERE key = ?)", key).Scan(&exists)
	})
	if err != nil {
		return false, fmt.Errorf("failed to check config existence %s: %w", key, err)
	}
	return exists, nil
}

// GetAll returns all config values (for debugging/admin purposes)
func (c *Config) GetAll() (map[string]string, error) {
	var result map[string]string
	err := c.db.With(func(conn *sql.DB) error {
		rows, err := conn.Query("SELECT key, value FROM settings")
	if err != nil {
			return fmt.Errorf("failed to get all config: %w", err)
	}
	defer rows.Close()

		result = make(map[string]string)
	for rows.Next() {
		var key, value string
		if err := rows.Scan(&key, &value); err != nil {
				return fmt.Errorf("failed to scan config row: %w", err)
		}
		result[key] = value
		}
		return nil
	})
	if err != nil {
		return nil, err
	}
	return result, nil
}

// --- Convenience methods for specific config values ---

// GoogleClientID returns the Google OAuth client ID
func (c *Config) GoogleClientID() string {
	return c.GetWithDefault(KeyGoogleClientID, "")
}

// GoogleClientSecret returns the Google OAuth client secret
func (c *Config) GoogleClientSecret() string {
	return c.GetWithDefault(KeyGoogleClientSecret, "")
}

// GoogleRedirectURL returns the Google OAuth redirect URL
func (c *Config) GoogleRedirectURL() string {
	return c.GetWithDefault(KeyGoogleRedirectURL, "")
}

// DiscordClientID returns the Discord OAuth client ID
func (c *Config) DiscordClientID() string {
	return c.GetWithDefault(KeyDiscordClientID, "")
}

// DiscordClientSecret returns the Discord OAuth client secret
func (c *Config) DiscordClientSecret() string {
	return c.GetWithDefault(KeyDiscordClientSecret, "")
}

// DiscordRedirectURL returns the Discord OAuth redirect URL
func (c *Config) DiscordRedirectURL() string {
	return c.GetWithDefault(KeyDiscordRedirectURL, "")
}

// IsLocalAuthEnabled returns whether local authentication is enabled
func (c *Config) IsLocalAuthEnabled() bool {
	return c.GetBoolWithDefault(KeyEnableLocalAuth, false)
}

// FixedAPIKey returns the fixed API key for testing
func (c *Config) FixedAPIKey() string {
	return c.GetWithDefault(KeyFixedAPIKey, "")
}

// IsProductionMode returns whether production mode is enabled
func (c *Config) IsProductionMode() bool {
	return c.GetBoolWithDefault(KeyProductionMode, false)
}

// AllowedOrigins returns the allowed CORS origins
func (c *Config) AllowedOrigins() string {
	return c.GetWithDefault(KeyAllowedOrigins, "")
}