package identity

import (
	"context"
	"encoding/hex"
	"log/slog"
	"net/http"
	"time"

	"git.asio.asia/nixevol/NixMsg/internal/app/port"
	"git.asio.asia/nixevol/NixMsg/internal/auth"
	"git.asio.asia/nixevol/NixMsg/internal/protocol"
	"git.asio.asia/nixevol/NixMsg/internal/store"
)

const (
	grantKindPassword = "password"
	grantKindReply    = "reply"
)

// Config 是身份服务依赖（注册 + self + 对话密码）。
type Config struct {
	DB     *store.DB
	Hash   auth.HashPool
	Locks  auth.LoginLocks
	Logger *slog.Logger
	Now    func() time.Time
	// ClientIP 仅注册 HTTP 用。
	ClientIP func(*http.Request) string

	// Sessions 签发会话令牌；改登录密码必填。
	Sessions auth.SessionTokens
	// MaxScheduleSeconds 限制 self.update 的 default_delay_ms。
	MaxScheduleSeconds int64
	// ConnControl 可选：logout 后踢线；未接线时为 nil。
	ConnControl port.ConnControl
}

// App 实现 identity.Service（含 I1 注册与 I2 self/对话密码）。
type App struct {
	handler            *RegisterHandler
	db                 *store.DB
	hash               auth.HashPool
	locks              auth.LoginLocks
	sessions           auth.SessionTokens
	maxScheduleSeconds int64
	connCtrl           port.ConnControl
	nowFn              func() time.Time
}

// New 构造完整身份服务。
func New(cfg Config) *App {
	if cfg.Logger == nil {
		cfg.Logger = slog.Default()
	}
	if cfg.Now == nil {
		cfg.Now = time.Now
	}
	if cfg.ClientIP == nil {
		cfg.ClientIP = clientIPFromRemoteAddr
	}
	if cfg.Sessions == nil {
		cfg.Sessions = auth.NewStubSessionTokens()
	}
	if cfg.Locks == nil {
		cfg.Locks = auth.NewStubLoginLocks()
	}
	h := NewRegisterHandler(RegisterConfig{
		DB:       cfg.DB,
		Hash:     cfg.Hash,
		Locks:    cfg.Locks,
		Logger:   cfg.Logger,
		Now:      cfg.Now,
		ClientIP: cfg.ClientIP,
	})
	return &App{
		handler:            h,
		db:                 cfg.DB,
		hash:               cfg.Hash,
		locks:              cfg.Locks,
		sessions:           cfg.Sessions,
		maxScheduleSeconds: cfg.MaxScheduleSeconds,
		connCtrl:           cfg.ConnControl,
		nowFn:              cfg.Now,
	}
}

// NewServer 兼容 I1：用注册配置构造 Service（会话令牌用 Stub）。
func NewServer(cfg RegisterConfig) *App {
	return New(Config{
		DB:       cfg.DB,
		Hash:     cfg.Hash,
		Locks:    cfg.Locks,
		Logger:   cfg.Logger,
		Now:      cfg.Now,
		ClientIP: cfg.ClientIP,
		Sessions: auth.NewStubSessionTokens(),
	})
}

func (a *App) now() time.Time { return a.nowFn() }

// Handler 返回可挂载的注册 HTTP 处理器。
func (a *App) Handler() http.Handler { return a.handler }

// Register 实现自助注册。
func (a *App) Register(ctx context.Context, req RegisterRequest) (RegisterResult, error) {
	preq := &protocol.RegisterRequest{
		RegistrationCode: req.RegistrationCode,
		ID:               req.ID,
		LoginPassword:    req.LoginPassword,
		Name:             req.Name,
		TalkPassword:     req.TalkPassword,
	}
	ip := req.RemoteIP
	if ip == "" {
		ip = "0.0.0.0"
	}
	result, apiErr := a.handler.register(ctx, preq, ip)
	if apiErr != nil {
		return RegisterResult{}, apiErr
	}
	return result, nil
}

func encodeSessionHash(hash []byte) string {
	return hex.EncodeToString(hash)
}

var _ Service = (*App)(nil)
var _ http.Handler = (*RegisterHandler)(nil)