package config

import (
	"fmt"
	"time"

	"github.com/spf13/viper"
)

type Config struct {
	Env       string                  `mapstructure:"env"`
	Server    ServerConfig            `mapstructure:"server"`
	Databases map[string]DatabaseConf `mapstructure:"databases"`
	Docker    DockerConfig            `mapstructure:"docker"`
	Auth      AuthConfig              `mapstructure:"auth"`
	RateLimit RateLimitConfig         `mapstructure:"rate_limit"`
}

type ServerConfig struct {
	Transport string `mapstructure:"transport"` // stdio | sse
	Addr      string `mapstructure:"addr"`       // :8080 for SSE mode
}

type DatabaseConf struct {
	Driver string `mapstructure:"driver"` // postgres | mysql
	DSN    string `mapstructure:"dsn"`
}

type DockerConfig struct {
	Enabled          bool                  `mapstructure:"enabled"`
	Host             string                `mapstructure:"host"` // unix:///var/run/docker.sock
	ContainerPattern string                `mapstructure:"container_pattern"`
	MaxLogBytes      int64                 `mapstructure:"max_log_bytes"`
	MaxLogLines      int                   `mapstructure:"max_log_lines"`
	MaxLogSince      time.Duration         `mapstructure:"max_log_since"`
}

type AuthConfig struct {
	Enabled    bool              `mapstructure:"enabled"`
	APIKeys    map[string]string `mapstructure:"api_keys"`  // key → description
	JWTSecret  string            `mapstructure:"jwt_secret"`
}

type RateLimitConfig struct {
	Enabled bool    `mapstructure:"enabled"`
	Rate    float64 `mapstructure:"rate"`   // 每秒允许的请求数
	Burst   int     `mapstructure:"burst"`  // 突发允许数
}

func Load(env string) (*Config, error) {
	v := viper.New()

	v.SetConfigName(env)  // dev.yaml / staging.yaml / prod.yaml
	v.SetConfigType("yaml")
	v.AddConfigPath("./config")
	v.AddConfigPath(".")
	v.AddConfigPath("/config")

	v.SetEnvPrefix("OPS_MCP")
	v.AutomaticEnv()

	if err := v.ReadInConfig(); err != nil {
		return nil, fmt.Errorf("read config: %w", err)
	}

	// 设置默认值
	v.SetDefault("server.transport", "stdio")
	v.SetDefault("server.addr", ":8080")
	v.SetDefault("docker.max_log_bytes", 1024*1024)
	v.SetDefault("docker.max_log_lines", 500)
	v.SetDefault("docker.max_log_since", "1h")
	v.SetDefault("rate_limit.rate", 10.0)
	v.SetDefault("rate_limit.burst", 20)

	var cfg Config
	if err := v.Unmarshal(&cfg); err != nil {
		return nil, fmt.Errorf("unmarshal config: %w", err)
	}

	return &cfg, nil
}