package config

import (
	"log/slog"
	"os"
	"strconv"
	"strings"
	"time"
)

type Config struct {
	AppEnv             string
	AppPublicURL       string
	AppTimezone        string
	HTTPAddr           string
	LogLevel           slog.Level
	DatabaseURL        string
	SuperAdminEmail    string
	SuperAdminPassword string
	JWTSecret          string
	AccessTokenTTL     time.Duration
	RefreshTokenTTL    time.Duration
	CORSAllowedOrigins []string
	CalendarProvider   string
	CalendarAPIBaseURL string
	CalendarAPIKey     string
	CalendarCacheTTL   time.Duration
	UploadMaxSizeMB    int
	UploadAllowedMIMEs []string
	StorageDriver      string
	StorageLocalPath   string
	SMTPHost           string
	SMTPPort           string
	SMTPUser           string
	SMTPPassword       string
	SMTPFromEmail      string
	SMTPFromName       string
}

func Load() Config {
	return Config{
		AppEnv:             env("APP_ENV", "development"),
		AppPublicURL:       env("APP_PUBLIC_URL", "http://localhost:5173"),
		AppTimezone:        env("APP_TIMEZONE", "America/Sao_Paulo"),
		HTTPAddr:           env("HTTP_ADDR", ":8080"),
		LogLevel:           logLevel(env("LOG_LEVEL", "info")),
		DatabaseURL:        env("DATABASE_URL", "postgres://mira:mira@localhost:5432/mira?sslmode=disable"),
		SuperAdminEmail:    env("SUPER_ADMIN_EMAIL", ""),
		SuperAdminPassword: env("SUPER_ADMIN_PASSWORD", ""),
		JWTSecret:          env("JWT_SECRET", ""),
		AccessTokenTTL:     minutes("JWT_ACCESS_TOKEN_TTL_MINUTES", 480),
		RefreshTokenTTL:    hours("JWT_REFRESH_TOKEN_TTL_DAYS", 7*24),
		CORSAllowedOrigins: list("CORS_ALLOWED_ORIGINS", "http://localhost:5173"),
		CalendarProvider:   env("CALENDAR_PROVIDER", "brasilapi"),
		CalendarAPIBaseURL: env("CALENDAR_API_BASE_URL", "https://brasilapi.com.br"),
		CalendarAPIKey:     env("CALENDAR_API_KEY", ""),
		CalendarCacheTTL:   hours("CALENDAR_CACHE_TTL_HOURS", 24),
		UploadMaxSizeMB:    integer("UPLOAD_MAX_SIZE_MB", 10),
		UploadAllowedMIMEs: list("UPLOAD_ALLOWED_MIME_TYPES", "image/jpeg,image/png,image/webp,application/pdf,application/msword,application/vnd.openxmlformats-officedocument.wordprocessingml.document"),
		StorageDriver:      env("STORAGE_DRIVER", "local"),
		StorageLocalPath:   env("STORAGE_LOCAL_PATH", "/var/lib/mira/uploads"),
		SMTPHost:           env("SMTP_HOST", ""),
		SMTPPort:           env("SMTP_PORT", "587"),
		SMTPUser:           env("SMTP_USER", ""),
		SMTPPassword:       envAlias("SMTP_PASS", "SMTP_PASSWORD", ""),
		SMTPFromEmail:      envAlias("MAIL_FROM", "SMTP_FROM_EMAIL", ""),
		SMTPFromName:       env("SMTP_FROM_NAME", "Mira"),
	}
}

func env(key, fallback string) string {
	value := strings.TrimSpace(os.Getenv(key))
	if value == "" {
		return fallback
	}
	return value
}

func envAlias(primary string, secondary string, fallback string) string {
	value := strings.TrimSpace(os.Getenv(primary))
	if value != "" {
		return value
	}
	return env(secondary, fallback)
}

func list(key, fallback string) []string {
	raw := env(key, fallback)
	parts := strings.Split(raw, ",")
	values := make([]string, 0, len(parts))
	for _, part := range parts {
		value := strings.TrimSpace(part)
		if value != "" {
			values = append(values, value)
		}
	}
	return values
}

func integer(key string, fallback int) int {
	value, err := strconv.Atoi(env(key, ""))
	if err != nil {
		return fallback
	}
	return value
}

func minutes(key string, fallback int) time.Duration {
	return time.Duration(integer(key, fallback)) * time.Minute
}

func hours(key string, fallback int) time.Duration {
	return time.Duration(integer(key, fallback)) * time.Hour
}

func logLevel(value string) slog.Level {
	switch strings.ToLower(value) {
	case "debug":
		return slog.LevelDebug
	case "warn":
		return slog.LevelWarn
	case "error":
		return slog.LevelError
	default:
		return slog.LevelInfo
	}
}