package config

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

type Config struct {
	AppHost              string
	AppPort              string
	BearerToken          string
	DBSettingsToken      string
	DBMaxOpenConns       int
	DBMaxIdleConns       int
	DBConnMaxLifetime    time.Duration
	ManagementDBHost     string
	ManagementDBPort     string
	ManagementDBDatabase string
	ManagementDBUsername string
	ManagementDBPassword string
	DBCredentialSecret   string
}

func Load(path string) (Config, error) {
	if err := loadDotEnv(path); err != nil {
		return Config{}, err
	}

	cfg := Config{
		AppHost:              env("APP_HOST", "0.0.0.0"),
		AppPort:              env("APP_PORT", "8080"),
		BearerToken:          env("CPONE_BEARER_TOKEN", ""),
		DBSettingsToken:      env("CPONE_DATABASE_SETTINGS_TOKEN", env("CPONE_BEARER_TOKEN", "")),
		DBMaxOpenConns:       envInt("DB_MAX_OPEN_CONNS", 25),
		DBMaxIdleConns:       envInt("DB_MAX_IDLE_CONNS", 25),
		DBConnMaxLifetime:    time.Duration(envInt("DB_CONN_MAX_LIFETIME_MINUTES", 5)) * time.Minute,
		ManagementDBHost:     env("CPONE_DB_HOST", "127.0.0.1"),
		ManagementDBPort:     env("CPONE_DB_PORT", "3306"),
		ManagementDBDatabase: env("CPONE_DB_DATABASE", "cpone_middleware"),
		ManagementDBUsername: env("CPONE_DB_USERNAME", "root"),
		ManagementDBPassword: env("CPONE_DB_PASSWORD", ""),
		DBCredentialSecret:   env("CPONE_DATABASE_CREDENTIAL_KEY", env("CPONE_DATABASE_SETTINGS_TOKEN", env("CPONE_BEARER_TOKEN", ""))),
	}

	if cfg.BearerToken == "" {
		return Config{}, fmt.Errorf("CPONE_BEARER_TOKEN wajib diisi")
	}
	if cfg.ManagementDBDatabase == "" {
		return Config{}, fmt.Errorf("CPONE_DB_DATABASE wajib diisi")
	}

	return cfg, nil
}

func (c Config) Addr() string {
	return c.AppHost + ":" + c.AppPort
}

func loadDotEnv(path string) error {
	file, err := os.Open(path)
	if err != nil {
		if os.IsNotExist(err) {
			return nil
		}
		return err
	}
	defer file.Close()

	scanner := bufio.NewScanner(file)
	for scanner.Scan() {
		line := strings.TrimSpace(scanner.Text())
		if line == "" || strings.HasPrefix(line, "#") {
			continue
		}

		key, value, ok := strings.Cut(line, "=")
		if !ok {
			continue
		}

		key = strings.TrimSpace(key)
		value = strings.TrimSpace(value)
		value = strings.Trim(value, `"'`)

		if key != "" {
			if _, alreadySet := os.LookupEnv(key); !alreadySet {
				_ = os.Setenv(key, value)
			}
		}
	}

	return scanner.Err()
}

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

func envInt(key string, fallback int) int {
	value := os.Getenv(key)
	if value == "" {
		return fallback
	}

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

	return parsed
}