package config

import (
	"fmt"
	"os"

	"gopkg.in/yaml.v3"
)

type Config struct {
	Server     ServerConfig     `yaml:"server"`
	Database   DatabaseConfig   `yaml:"database"`
	JWT        JWTConfig        `yaml:"jwt"`
	Controller ControllerConfig `yaml:"controller"`
	Agent      AgentConfig      `yaml:"agent"`
	Relay      RelayConfig      `yaml:"relay"`
	CORS       CORSConfig       `yaml:"cors"`
	RateLimit  RateLimitConfig  `yaml:"rate_limit"`
	Logging    LoggingConfig    `yaml:"logging"`
	Env        EnvConfig        `yaml:"env"`
}

type ServerConfig struct {
	Port int `yaml:"port"`
}

func (s *ServerConfig) Addr() string {
	return fmt.Sprintf(":%d", s.Port)
}

type DatabaseConfig struct {
	Driver     string       `yaml:"driver"`
	AutoMigrate bool        `yaml:"auto_migrate"`
	InitData   bool         `yaml:"init_data"`
	SQLite     SQLiteConfig `yaml:"sqlite"`
	MySQL      MySQLConfig  `yaml:"mysql"`
}

type SQLiteConfig struct {
	Path string `yaml:"path"`
}

type MySQLConfig struct {
	Host         string `yaml:"host"`
	Port         int    `yaml:"port"`
	Username     string `yaml:"username"`
	Password     string `yaml:"password"`
	Database     string `yaml:"database"`
	Charset      string `yaml:"charset"`
	MaxIdleConns int    `yaml:"max_idle_conns"`
	MaxOpenConns int    `yaml:"max_open_conns"`
}

type JWTConfig struct {
	Secret      string `yaml:"secret"`
	ExpireHours int    `yaml:"expire_hours"`
}

type ControllerConfig struct {
	ListenPort     int    `yaml:"listen_port"`
	PublicEndpoint string `yaml:"public_endpoint"`
	PlanetID       string `yaml:"planet_id"`
}

type AgentConfig struct {
	ControllerURL string   `yaml:"controller_url"`
	ListenPort    int      `yaml:"listen_port"`
	TAPName       string   `yaml:"tap_name"`
	TAPMTU        int      `yaml:"tap_mtu"`
	NetworkID     uint32   `yaml:"network_id"`
	PSK           string   `yaml:"psk"`
	StaticPeers   []string `yaml:"static_peers"`
}

type RelayConfig struct {
	ListenPort int    `yaml:"listen_port"`
	Realm      string `yaml:"realm"`
}

type CORSConfig struct {
	AllowedOrigins []string `yaml:"allowed_origins"`
}

type RateLimitConfig struct {
	Enabled           bool  `yaml:"enabled"`
	RequestsPerSecond int   `yaml:"requests_per_second"`
	BurstSize         int   `yaml:"burst_size"`
}

type LoggingConfig struct {
	Level  string `yaml:"level"`
	Format string `yaml:"format"`
}

type EnvConfig struct {
	Name string `yaml:"name"`
}

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 := yaml.Unmarshal(data, &cfg); err != nil {
		return nil, fmt.Errorf("parse config: %w", err)
	}
	setDefaults(&cfg)
	return &cfg, nil
}

func setDefaults(cfg *Config) {
	if cfg.Server.Port == 0 {
		cfg.Server.Port = 10001
	}
	if cfg.Controller.ListenPort == 0 {
		cfg.Controller.ListenPort = 9993
	}
	if cfg.Agent.TAPName == "" {
		cfg.Agent.TAPName = "zeromesh0"
	}
	if cfg.Agent.TAPMTU == 0 {
		cfg.Agent.TAPMTU = 2800
	}
	if cfg.JWT.ExpireHours == 0 {
		cfg.JWT.ExpireHours = 720
	}
	if cfg.Logging.Level == "" {
		cfg.Logging.Level = "info"
	}
	if cfg.Env.Name == "" {
		cfg.Env.Name = "dev"
	}
}

func (d *DatabaseConfig) BuildDSN() string {
	if d.Driver == "mysql" {
		return fmt.Sprintf("%s:%s@tcp(%s:%d)/%s?charset=%s&parseTime=True&loc=Local",
			d.MySQL.Username, d.MySQL.Password, d.MySQL.Host, d.MySQL.Port, d.MySQL.Database, d.MySQL.Charset)
	}
	return ""
}