package config

import (
	"fmt"
	"os"
	"strconv"
)

// Config holds all application configuration
type Config struct {
	// API Keys
	PlanToEatAPIKey   string
	PlanToEatSession  string // Session cookie for web scraping
	TrelloAPIKey      string
	TrelloToken       string

	// Google Calendar
	GoogleCredentialsFile string
	GoogleCalendarID      string

	// Google Tasks (real 3-legged OAuth -- service-account auth cannot see a
	// user's personal task lists, see NewGoogleTasksClient's doc comment)
	GoogleTasksListID       string
	GoogleOAuthClientID     string
	GoogleOAuthClientSecret string
	// GoogleOAuthRedirectURL must exactly match an "Authorized redirect URI"
	// on the OAuth 2.0 Client ID in Google Cloud Console -- kept as its own
	// explicit var rather than derived from WebAuthnOrigin (which isn't set
	// in production; passkeys aren't configured either) so there's exactly
	// one place that has to match Console, not two things that have to
	// agree with each other.
	GoogleOAuthRedirectURL string

	// Paths
	DatabasePath string
	MigrationDir string
	TemplateDir  string
	StaticDir    string
	DocsDir      string // root of superpowers spec/plan docs, served read-only at /docs

	// Server
	Port            string
	CacheTTLMinutes int
	Debug           bool

	// Display
	Timezone string // IANA timezone name (e.g., "Pacific/Honolulu")

	// WebAuthn
	WebAuthnRPID   string // Relying Party ID (domain, e.g., "doot.terst.org")
	WebAuthnOrigin string // Expected origin (e.g., "https://doot.terst.org")

	// Widget API
	WidgetToken string // Static bearer token for /api/widget (WIDGET_TOKEN env var)

	// Claudomator
	ClaudomatorURL string // URL of Claudomator service

	// Service gateway — additional upstream services proxied through doot's auth layer
	PlaygroundURL string // URL of playground demo service (optional)
	ScoutURL      string // URL of scout listing feed service (optional)
	HawaiiURL     string // URL of Hawaii county data dashboard (optional)
}

// Load reads configuration from environment variables
func Load() (*Config, error) {
	cfg := &Config{
		// API Keys
		PlanToEatAPIKey:  os.Getenv("PLANTOEAT_API_KEY"),
		PlanToEatSession: os.Getenv("PLANTOEAT_SESSION"),
		TrelloAPIKey:     os.Getenv("TRELLO_API_KEY"),
		TrelloToken:      os.Getenv("TRELLO_TOKEN"),

		// Google Calendar
		GoogleCredentialsFile: os.Getenv("GOOGLE_CREDENTIALS_FILE"),
		GoogleCalendarID:      getEnvWithDefault("GOOGLE_CALENDAR_ID", "primary"),

		// Google Tasks
		GoogleTasksListID:       getEnvWithDefault("GOOGLE_TASKS_LIST_ID", "@default"),
		GoogleOAuthClientID:     os.Getenv("GOOGLE_OAUTH_CLIENT_ID"),
		GoogleOAuthClientSecret: os.Getenv("GOOGLE_OAUTH_CLIENT_SECRET"),
		GoogleOAuthRedirectURL:  getEnvWithDefault("GOOGLE_OAUTH_REDIRECT_URL", "https://doot.terst.org/settings/google-tasks/callback"),

		// Paths
		DatabasePath: getEnvWithDefault("DATABASE_PATH", "./dashboard.db"),
		MigrationDir: getEnvWithDefault("MIGRATION_DIR", "migrations"),
		TemplateDir:  getEnvWithDefault("TEMPLATE_DIR", "web/templates"),
		StaticDir:    getEnvWithDefault("STATIC_DIR", "web/static"),
		DocsDir:      getEnvWithDefault("DOCS_DIR", "docs/superpowers"),

		// Server
		Port:            getEnvWithDefault("PORT", "8080"),
		CacheTTLMinutes: getEnvAsInt("CACHE_TTL_MINUTES", 5),
		Debug:           getEnvAsBool("DEBUG", false),

		// Display
		Timezone: getEnvWithDefault("TIMEZONE", "Pacific/Honolulu"),

		// WebAuthn
		WebAuthnRPID:   os.Getenv("WEBAUTHN_RP_ID"),
		WebAuthnOrigin: os.Getenv("WEBAUTHN_ORIGIN"),

		// Widget API
		WidgetToken: os.Getenv("WIDGET_TOKEN"),

		// Claudomator
		ClaudomatorURL: getEnvWithDefault("CLAUDOMATOR_URL", "http://127.0.0.1:8484"),

		// Service gateway
		PlaygroundURL: os.Getenv("PLAYGROUND_URL"),
		ScoutURL:      os.Getenv("SCOUT_URL"),
		HawaiiURL:     os.Getenv("HAWAII_URL"),
	}

	// Validate required fields
	if err := cfg.Validate(); err != nil {
		return nil, err
	}

	return cfg, nil
}

// Validate checks that required configuration is present
func (c *Config) Validate() error {
	if c.TrelloAPIKey == "" {
		return fmt.Errorf("TRELLO_API_KEY is required")
	}

	if c.TrelloToken == "" {
		return fmt.Errorf("TRELLO_TOKEN is required")
	}

	return nil
}

// HasPlanToEat checks if PlanToEat is configured (API key or session)
func (c *Config) HasPlanToEat() bool {
	return c.PlanToEatAPIKey != "" || c.PlanToEatSession != ""
}

// HasPlanToEatSession checks if PlanToEat session cookie is configured
func (c *Config) HasPlanToEatSession() bool {
	return c.PlanToEatSession != ""
}

// HasTrello checks if Trello is configured
func (c *Config) HasTrello() bool {
	return c.TrelloAPIKey != "" && c.TrelloToken != ""
}

// HasGoogleCalendar checks if Google Calendar is configured
func (c *Config) HasGoogleCalendar() bool {
	return c.GoogleCredentialsFile != ""
}

// HasGoogleTasks checks if Google Tasks OAuth is configured (client ID and
// secret from Google Cloud Console) -- doesn't mean a user has actually
// connected yet, that's the oauth_tokens row, checked separately.
func (c *Config) HasGoogleTasks() bool {
	return c.GoogleOAuthClientID != "" && c.GoogleOAuthClientSecret != ""
}

// getEnvWithDefault returns environment variable value or default if not set
func getEnvWithDefault(key, defaultValue string) string {
	if value := os.Getenv(key); value != "" {
		return value
	}
	return defaultValue
}

// getEnvAsInt returns environment variable as int or default if not set or invalid
func getEnvAsInt(key string, defaultValue int) int {
	valueStr := os.Getenv(key)
	if valueStr == "" {
		return defaultValue
	}

	value, err := strconv.Atoi(valueStr)
	if err != nil {
		return defaultValue
	}

	return value
}

// getEnvAsBool returns environment variable as bool or default if not set
func getEnvAsBool(key string, defaultValue bool) bool {
	valueStr := os.Getenv(key)
	if valueStr == "" {
		return defaultValue
	}

	value, err := strconv.ParseBool(valueStr)
	if err != nil {
		return defaultValue
	}

	return value
}