package config

import (
	"encoding/json"
	"fmt"
	"os"
)

type Config struct {
	AdminToken string `json:"adminToken"`
	AuthAPIURL string `json:"authApiUrl"`

	// Database DSN. If empty, falls back to the test DB DSN.
	// Format: "user:pass@tcp(host:port)/dbname?charset=utf8mb4&parseTime=True&loc=Local"
	DatabaseDSN string `json:"databaseDsn"`
}

// Default DSNs for each environment.
const (
	TestDSN = "mengyastore-test:mengyastore-test@tcp(10.1.1.100:3306)/mengyastore-test?charset=utf8mb4&parseTime=True&loc=Local"
	ProdDSN = "mengyastore:mengyastore@tcp(192.168.1.100:3306)/mengyastore?charset=utf8mb4&parseTime=True&loc=Local"
)

func Load(path string) (*Config, error) {
	data, err := os.ReadFile(path)
	if err != nil {
		return nil, fmt.Errorf("read config: %w", err)
	}
	var cfg Config
	if err := json.Unmarshal(data, &cfg); err != nil {
		return nil, fmt.Errorf("parse config: %w", err)
	}
	if cfg.AdminToken == "" {
		cfg.AdminToken = "shumengya520"
	}
	// Default to test DB if not configured; environment variable overrides config file.
	if dsn := os.Getenv("DATABASE_DSN"); dsn != "" {
		cfg.DatabaseDSN = dsn
	}
	if cfg.DatabaseDSN == "" {
		cfg.DatabaseDSN = TestDSN
	}
	return &cfg, nil
}