package config

import (
	"fmt"
	"os"

	"gopkg.in/yaml.v3"
)

// LogConfig holds logging configuration values.
type LogConfig struct {
	Level        string `yaml:"level"`         // debug, info, warn, error (default: info)
	Encoding     string `yaml:"encoding"`      // json, console (default: json)
	OutputStdout *bool  `yaml:"output_stdout"` // 输出到终端 (default: true)
	FilePath     string `yaml:"file_path"`     // log file path (for rotation)
	MaxSize      int    `yaml:"max_size"`      // MB per file (default: 100)
	MaxBackups   int    `yaml:"max_backups"`   // retained files (default: 5)
	MaxAge       int    `yaml:"max_age"`       // days to retain (default: 30)
	Compress     bool   `yaml:"compress"`      // gzip old files (default: true)
	GormLevel    string `yaml:"gorm_level"`    // GORM SQL log level (default: warn)
}

// MinioConfig holds MinIO object storage configuration values.
type MinioConfig struct {
	Endpoint     string `yaml:"endpoint"`       // MinIO server address
	AccessKey    string `yaml:"access_key"`     // access key
	SecretKey    string `yaml:"secret_key"`     // secret key
	Bucket       string `yaml:"bucket"`         // bucket name
	UseSSL       bool   `yaml:"use_ssl"`        // use TLS connection
	ChunkSize    int64  `yaml:"chunk_size"`     // upload chunk size in bytes (default: 16MB)
	MaxFileSize  int64  `yaml:"max_file_size"`  // max file size in bytes (default: 50GB)
	MinChunkSize int64  `yaml:"min_chunk_size"` // minimum chunk size in bytes (default: 5MB)
	SessionTTL   int    `yaml:"session_ttl"`    // session TTL in hours (default: 48)
}

// Config holds all application configuration values.
type Config struct {
	ServerPort      string      `yaml:"server_port"`
	SlurmAPIURL     string      `yaml:"slurm_api_url"`
	SlurmUserName   string      `yaml:"slurm_user_name"`
	SlurmJWTKeyPath string      `yaml:"slurm_jwt_key_path"`
	MySQLDSN        string      `yaml:"mysql_dsn"`
	WorkDirBase     string      `yaml:"work_dir_base"` // base directory for job work dirs
	Log             LogConfig   `yaml:"log"`
	Minio           MinioConfig `yaml:"minio"`
}

// Load reads a YAML configuration file and returns a parsed Config.
// If path is empty, it defaults to "./config.yaml".
func Load(path string) (*Config, error) {
	if path == "" {
		path = "./config.yaml"
	}

	data, err := os.ReadFile(path)
	if err != nil {
		return nil, fmt.Errorf("read config file %s: %w", path, err)
	}

	var cfg Config
	if err := yaml.Unmarshal(data, &cfg); err != nil {
		return nil, fmt.Errorf("parse config file %s: %w", path, err)
	}

	if cfg.Minio.ChunkSize == 0 {
		cfg.Minio.ChunkSize = 16 << 20 // 16MB
	}
	if cfg.Minio.MaxFileSize == 0 {
		cfg.Minio.MaxFileSize = 50 << 30 // 50GB
	}
	if cfg.Minio.MinChunkSize == 0 {
		cfg.Minio.MinChunkSize = 5 << 20 // 5MB
	}
	if cfg.Minio.SessionTTL == 0 {
		cfg.Minio.SessionTTL = 48
	}

	return &cfg, nil
}