package main

import (
	"os"
	"strconv"
	"strings"
	"time"
)

type config struct {
	Port                            string
	WebDir                          string
	AppBaseURL                      string
	MCPResourceURL                  string
	CorsOrigins                     []string
	DatabaseURL                     string
	MinIOEndpoint                   string
	MinIOBucket                     string
	MinIOAccessKey                  string
	MinIOSecretKey                  string
	AssetEncryptionEnabled          bool
	AuthDisabled                    bool
	KeycloakIssuer                  string
	KeycloakIssuerInternal          string
	KeycloakAudience                string
	StripeSecretKey                 string
	StripeAPIBaseURL                string
	StripeWebhookSecret             string
	StripeWebhookTolerance          time.Duration
	StripeAllowedPriceIDs           []string
	StripeCheckoutSuccessURL        string
	StripeCheckoutCancelURL         string
	BillingEventRetentionDays       int
	EntitlementHistoryRetentionDays int
	EducationalRecordRetentionDays  int
	DefaultTrialDays                int
	DefaultFreeDays                 int
	KeycloakThemeDeployEnabled      bool
	NotificationProvider            string
	SendGridAPIKey                  string
	SendGridFromEmail               string
	SendGridAPIBaseURL              string
	ShutdownTimeout                 time.Duration
}

func loadConfig() config {
	return config{
		Port:                            getEnv("PORT", "8080"),
		WebDir:                          strings.TrimSpace(getEnv("WEB_DIR", "")),
		AppBaseURL:                      strings.TrimRight(getEnv("APP_BASE_URL", "http://localhost:5173"), "/"),
		MCPResourceURL:                  strings.TrimRight(getEnv("MCP_RESOURCE_URL", "http://localhost:8080/api/mcp"), "/"),
		CorsOrigins:                     parseList(getEnv("CORS_ALLOWED_ORIGINS", "*")),
		DatabaseURL:                     getEnv("DATABASE_URL", "postgres://cms:cms@postgres:5432/cms?sslmode=disable"),
		MinIOEndpoint:                   getEnv("MINIO_ENDPOINT", ""),
		MinIOBucket:                     getEnv("MINIO_BUCKET", ""),
		MinIOAccessKey:                  getEnv("MINIO_ACCESS_KEY", ""),
		MinIOSecretKey:                  getEnv("MINIO_SECRET_KEY", ""),
		AssetEncryptionEnabled:          getEnvBool("ASSET_ENCRYPTION_ENABLED", false),
		AuthDisabled:                    getEnvBool("AUTH_DISABLED", false),
		KeycloakIssuer:                  getEnv("KEYCLOAK_ISSUER", "http://localhost:8081/realms/cms"),
		KeycloakIssuerInternal:          getEnv("KEYCLOAK_ISSUER_INTERNAL", "http://keycloak:8080/realms/cms"),
		KeycloakAudience:                getEnv("KEYCLOAK_AUDIENCE", "cms-backend"),
		StripeSecretKey:                 getEnv("STRIPE_SECRET_KEY", ""),
		StripeAPIBaseURL:                getEnv("STRIPE_API_BASE_URL", "https://api.stripe.com"),
		StripeWebhookSecret:             getEnv("STRIPE_WEBHOOK_SECRET", ""),
		StripeWebhookTolerance:          time.Duration(getEnvInt("STRIPE_WEBHOOK_TOLERANCE_SECONDS", 300)) * time.Second,
		StripeAllowedPriceIDs:           parseOptionalList(getEnv("STRIPE_ALLOWED_PRICE_IDS", "")),
		StripeCheckoutSuccessURL:        getEnv("STRIPE_CHECKOUT_SUCCESS_URL", "http://localhost:5173/learn/billing?checkout=success"),
		StripeCheckoutCancelURL:         getEnv("STRIPE_CHECKOUT_CANCEL_URL", "http://localhost:5173/learn/billing?checkout=cancel"),
		BillingEventRetentionDays:       getEnvInt("BILLING_EVENT_RETENTION_DAYS", 365),
		EntitlementHistoryRetentionDays: getEnvInt("ENTITLEMENT_HISTORY_RETENTION_DAYS", 730),
		EducationalRecordRetentionDays:  getEnvInt("EDUCATIONAL_RECORD_RETENTION_DAYS", 2555),
		DefaultTrialDays:                getEnvInt("DEFAULT_TRIAL_DAYS", 14),
		DefaultFreeDays:                 getEnvInt("DEFAULT_FREE_ACCESS_DAYS", 3650),
		KeycloakThemeDeployEnabled:      getEnvBool("KEYCLOAK_THEME_DEPLOY_ENABLED", true),
		NotificationProvider:            strings.ToLower(getEnv("NOTIFICATION_PROVIDER", "noop")),
		SendGridAPIKey:                  getEnv("SENDGRID_API_KEY", ""),
		SendGridFromEmail:               getEnv("SENDGRID_FROM_EMAIL", ""),
		SendGridAPIBaseURL:              getEnv("SENDGRID_API_BASE_URL", "https://api.sendgrid.com"),
		ShutdownTimeout:                 time.Duration(getEnvInt("SHUTDOWN_TIMEOUT_SECONDS", 10)) * time.Second,
	}
}

func getEnv(key, fallback string) string {
	value, ok := os.LookupEnv(key)
	if !ok || strings.TrimSpace(value) == "" {
		return fallback
	}
	return value
}

func getEnvInt(key string, fallback int) int {
	raw := strings.TrimSpace(getEnv(key, ""))
	if raw == "" {
		return fallback
	}
	value, err := strconv.Atoi(raw)
	if err != nil {
		return fallback
	}
	return value
}

func getEnvBool(key string, fallback bool) bool {
	raw := strings.TrimSpace(strings.ToLower(getEnv(key, "")))
	if raw == "" {
		return fallback
	}
	return raw == "1" || raw == "true" || raw == "yes" || raw == "on"
}

func parseList(raw string) []string {
	if strings.TrimSpace(raw) == "" {
		return []string{"*"}
	}
	parts := strings.Split(raw, ",")
	out := make([]string, 0, len(parts))
	for _, part := range parts {
		item := strings.TrimSpace(part)
		if item != "" {
			out = append(out, item)
		}
	}
	if len(out) == 0 {
		return []string{"*"}
	}
	return out
}

func parseOptionalList(raw string) []string {
	if strings.TrimSpace(raw) == "" {
		return []string{}
	}
	parts := strings.Split(raw, ",")
	out := make([]string, 0, len(parts))
	for _, part := range parts {
		item := strings.TrimSpace(part)
		if item != "" {
			out = append(out, item)
		}
	}
	return out
}