package parsing

import (
	"net"
	"net/url"

	"github.com/go-gost/core/admission"
	"github.com/go-gost/core/auth"
	"github.com/go-gost/core/bypass"
	"github.com/go-gost/core/chain"
	"github.com/go-gost/core/hosts"
	"github.com/go-gost/core/logger"
	"github.com/go-gost/core/recorder"
	"github.com/go-gost/core/resolver"
	admission_impl "github.com/go-gost/x/admission"
	auth_impl "github.com/go-gost/x/auth"
	bypass_impl "github.com/go-gost/x/bypass"
	"github.com/go-gost/x/config"
	hosts_impl "github.com/go-gost/x/hosts"
	"github.com/go-gost/x/internal/loader"
	recorder_impl "github.com/go-gost/x/recorder"
	"github.com/go-gost/x/registry"
	resolver_impl "github.com/go-gost/x/resolver"
)

func ParseAuther(cfg *config.AutherConfig) auth.Authenticator {
	if cfg == nil {
		return nil
	}

	m := make(map[string]string)

	for _, user := range cfg.Auths {
		if user.Username == "" {
			continue
		}
		m[user.Username] = user.Password
	}

	opts := []auth_impl.Option{
		auth_impl.AuthsPeriodOption(m),
		auth_impl.ReloadPeriodOption(cfg.Reload),
		auth_impl.LoggerOption(logger.Default().WithFields(map[string]any{
			"kind":   "auther",
			"auther": cfg.Name,
		})),
	}
	if cfg.File != nil && cfg.File.Path != "" {
		opts = append(opts, auth_impl.FileLoaderOption(loader.FileLoader(cfg.File.Path)))
	}
	if cfg.Redis != nil && cfg.Redis.Addr != "" {
		opts = append(opts, auth_impl.RedisLoaderOption(loader.RedisHashLoader(
			cfg.Redis.Addr,
			loader.DBRedisLoaderOption(cfg.Redis.DB),
			loader.PasswordRedisLoaderOption(cfg.Redis.Password),
			loader.KeyRedisLoaderOption(cfg.Redis.Key),
		)))
	}

	return auth_impl.NewAuthenticator(opts...)
}

func ParseAutherFromAuth(au *config.AuthConfig) auth.Authenticator {
	if au == nil || au.Username == "" {
		return nil
	}
	return auth_impl.NewAuthenticator(
		auth_impl.AuthsPeriodOption(
			map[string]string{
				au.Username: au.Password,
			},
		))
}

func parseAuth(cfg *config.AuthConfig) *url.Userinfo {
	if cfg == nil || cfg.Username == "" {
		return nil
	}

	if cfg.Password == "" {
		return url.User(cfg.Username)
	}
	return url.UserPassword(cfg.Username, cfg.Password)
}

func parseSelector(cfg *config.SelectorConfig) chain.Selector {
	if cfg == nil {
		return nil
	}

	var strategy chain.Strategy
	switch cfg.Strategy {
	case "round", "rr":
		strategy = chain.RoundRobinStrategy()
	case "random", "rand":
		strategy = chain.RandomStrategy()
	case "fifo", "ha":
		strategy = chain.FIFOStrategy()
	default:
		strategy = chain.RoundRobinStrategy()
	}

	return chain.NewSelector(
		strategy,
		chain.InvalidFilter(),
		chain.FailFilter(cfg.MaxFails, cfg.FailTimeout),
	)
}

func ParseAdmission(cfg *config.AdmissionConfig) admission.Admission {
	if cfg == nil {
		return nil
	}
	opts := []admission_impl.Option{
		admission_impl.MatchersOption(cfg.Matchers),
		admission_impl.ReverseOption(cfg.Reverse),
		admission_impl.ReloadPeriodOption(cfg.Reload),
		admission_impl.LoggerOption(logger.Default().WithFields(map[string]any{
			"kind":      "admission",
			"admission": cfg.Name,
		})),
	}
	if cfg.File != nil && cfg.File.Path != "" {
		opts = append(opts, admission_impl.FileLoaderOption(loader.FileLoader(cfg.File.Path)))
	}
	if cfg.Redis != nil && cfg.Redis.Addr != "" {
		opts = append(opts, admission_impl.RedisLoaderOption(loader.RedisSetLoader(
			cfg.Redis.Addr,
			loader.DBRedisLoaderOption(cfg.Redis.DB),
			loader.PasswordRedisLoaderOption(cfg.Redis.Password),
			loader.KeyRedisLoaderOption(cfg.Redis.Key),
		)))
	}
	return admission_impl.NewAdmission(opts...)
}

func ParseBypass(cfg *config.BypassConfig) bypass.Bypass {
	if cfg == nil {
		return nil
	}

	opts := []bypass_impl.Option{
		bypass_impl.MatchersOption(cfg.Matchers),
		bypass_impl.ReverseOption(cfg.Reverse),
		bypass_impl.ReloadPeriodOption(cfg.Reload),
		bypass_impl.LoggerOption(logger.Default().WithFields(map[string]any{
			"kind":   "bypass",
			"bypass": cfg.Name,
		})),
	}
	if cfg.File != nil && cfg.File.Path != "" {
		opts = append(opts, bypass_impl.FileLoaderOption(loader.FileLoader(cfg.File.Path)))
	}
	if cfg.Redis != nil && cfg.Redis.Addr != "" {
		opts = append(opts, bypass_impl.RedisLoaderOption(loader.RedisSetLoader(
			cfg.Redis.Addr,
			loader.DBRedisLoaderOption(cfg.Redis.DB),
			loader.PasswordRedisLoaderOption(cfg.Redis.Password),
			loader.KeyRedisLoaderOption(cfg.Redis.Key),
		)))
	}
	return bypass_impl.NewBypass(opts...)
}

func ParseResolver(cfg *config.ResolverConfig) (resolver.Resolver, error) {
	if cfg == nil {
		return nil, nil
	}
	var nameservers []resolver_impl.NameServer
	for _, server := range cfg.Nameservers {
		nameservers = append(nameservers, resolver_impl.NameServer{
			Addr:     server.Addr,
			Chain:    registry.ChainRegistry().Get(server.Chain),
			TTL:      server.TTL,
			Timeout:  server.Timeout,
			ClientIP: net.ParseIP(server.ClientIP),
			Prefer:   server.Prefer,
			Hostname: server.Hostname,
		})
	}

	return resolver_impl.NewResolver(
		nameservers,
		resolver_impl.LoggerResolverOption(
			logger.Default().WithFields(map[string]any{
				"kind":     "resolver",
				"resolver": cfg.Name,
			}),
		),
	)
}

func ParseHosts(cfg *config.HostsConfig) hosts.HostMapper {
	if cfg == nil || len(cfg.Mappings) == 0 {
		return nil
	}
	hosts := hosts_impl.NewHosts()
	hosts.Logger = logger.Default().WithFields(map[string]any{
		"kind":  "hosts",
		"hosts": cfg.Name,
	})

	for _, host := range cfg.Mappings {
		if host.IP == "" || host.Hostname == "" {
			continue
		}

		ip := net.ParseIP(host.IP)
		if ip == nil {
			continue
		}
		hosts.Map(ip, host.Hostname, host.Aliases...)
	}
	return hosts
}

func ParseRecorder(cfg *config.RecorderConfig) (r recorder.Recorder) {
	if cfg == nil {
		return nil
	}

	if cfg.File != nil && cfg.File.Path != "" {
		return recorder_impl.FileRecorder(cfg.File.Path,
			recorder_impl.SepRecorderOption(cfg.File.Sep))
	}

	if cfg.Redis != nil &&
		cfg.Redis.Addr != "" &&
		cfg.Redis.Key != "" {
		switch cfg.Redis.Type {
		case "list": // redis list
			return recorder_impl.RedisListRecorder(cfg.Redis.Addr,
				recorder_impl.DBRedisRecorderOption(cfg.Redis.DB),
				recorder_impl.KeyRedisRecorderOption(cfg.Redis.Key),
				recorder_impl.PasswordRedisRecorderOption(cfg.Redis.Password),
			)
		default: // redis set
			return recorder_impl.RedisSetRecorder(cfg.Redis.Addr,
				recorder_impl.DBRedisRecorderOption(cfg.Redis.DB),
				recorder_impl.KeyRedisRecorderOption(cfg.Redis.Key),
				recorder_impl.PasswordRedisRecorderOption(cfg.Redis.Password),
			)
		}
	}

	return
}