// Package modules - 好友组队系统模块
// 对齐GDD-34 好友与组队系统设计
package modules

import (
	"context"
	"database/sql"
	"encoding/json"
	"time"

	"github.com/heroiclabs/nakama-common/runtime"
	"github.com/jackc/pgx/v5"
)

// RegisterFriendParty 注册好友组队相关 RPC。
func RegisterFriendParty(initializer runtime.Initializer) error {
	rpcs := map[string]func(runtime.Initializer) error{
		"FriendPartyService/AddFriend":       addFriend,
		"FriendPartyService/RemoveFriend":     removeFriend,
		"FriendPartyService/GetFriends":       getFriends,
		"FriendPartyService/AcceptFriend":     acceptFriend,
		"FriendPartyService/CreateParty":      createParty,
		"FriendPartyService/JoinParty":        joinParty,
		"FriendPartyService/LeaveParty":       leaveParty,
		"FriendPartyService/GetPartyInfo":     getPartyInfo,
	}
	for path, fn := range rpcs {
		if err := initializer.RegisterRpc(path, fn); err != nil {
			return err
		}
	}
	return nil
}

type addFriendReq struct {
	TargetCharacterID string `json:"target_character_id"`
}

type removeFriendReq struct {
	FriendID string `json:"friend_id"`
}

type getFriendsReq struct {
	CharacterID string `json:"character_id"`
}

type acceptFriendReq struct {
	RelationID string `json:"relation_id"`
}

type createPartyReq struct {
	MaxMembers int32  `json:"max_members"`
	PartyName  string `json:"party_name"`
}

type joinPartyReq struct {
	PartyID string `json:"party_id"`
}

type leavePartyReq struct {
	PartyID string `json:"party_id"`
}

type getPartyInfoReq struct {
	PartyID string `json:"party_id"`
}

type friendData struct {
	CharacterID string    `json:"character_id"`
	Name        string    `json:"name"`
	RaceID      string    `json:"race_id"`
	RealmTier   int32     `json:"realm_tier"`
	IsOnline    bool      `json:"is_online"`
	LastSeen    time.Time `json:"last_seen"`
	Intimacy    int32     `json:"intimacy"`
	Status      string    `json:"status"` // active/cooldown/dissolved
}

type partyData struct {
	PartyID     string      `json:"party_id"`
	LeaderID    string      `json:"leader_id"`
	LeaderName  string      `json:"leader_name"`
	Members     interface{} `json:"members"`
	MaxMembers  int32       `json:"max_members"`
	PartyName   string      `json:"party_name"`
	WorldTier   int32       `json:"world_tier"`
	RealmTier   int32       `json:"realm_tier"`
	Status      string      `json:"status"`
	CreatedAt   time.Time   `json:"created_at"`
}

type partyMemberData struct {
	CharacterID string `json:"character_id"`
	Name        string `json:"name"`
	RaceID      string `json:"race_id"`
	RealmTier   int32  `json:"realm_tier"`
	Role        string `json:"role"` // leader/member
	IsReady     bool   `json:"is_ready"`
}

func addFriend(ctx context.Context, logger runtime.Logger, db *sql.DB, nk runtime.NakamaModule, payload string) (string, error) {
	traceID := newTraceID()
	uid := userIDFromCtx(ctx)
	if uid == "" {
		return errResp(1001, "missing token", traceID)
	}

	var req addFriendReq
	if err := json.Unmarshal([]byte(payload), &req); err != nil {
		return errResp(2001, "invalid payload", traceID)
	}

	// 获取发起者角色ID
	var charID string
	err := hhdbPool.QueryRow(ctx, `
		SELECT id FROM characters WHERE player_id = $1 AND status = 'active'
		ORDER BY created_at DESC LIMIT 1
	`, uid).Scan(&charID)
	if err != nil {
		return errResp(4002, "character not found", traceID)
	}

	// 检查目标是否存在
	var targetName string
	err = hhdbPool.QueryRow(ctx, `
		SELECT name FROM characters WHERE id = $1 AND status = 'active'
	`, req.TargetCharacterID).Scan(&targetName)
	if err != nil {
		return errResp(8401, "target not found", traceID)
	}

	// 检查是否已是好友
	var existingCount int32
	err = hhdbPool.QueryRow(ctx, `
		SELECT COUNT(*) FROM social_relations
		WHERE ((character_a_id = $1 AND character_b_id = $2)
		       OR (character_a_id = $2 AND character_b_id = $1))
		AND relation_type = 'friend' AND status = 'active'
	`, charID, req.TargetCharacterID).Scan(&existingCount)
	if err == nil && existingCount > 0 {
		return errResp(8402, "already friends", traceID)
	}

	// 创建好友关系（待接受）
	_, err = hhdbPool.Exec(ctx, `
		INSERT INTO social_relations (character_a_id, character_b_id, relation_type, intimacy, status)
		VALUES ($1, $2, 'friend', 0, 'active')
		ON CONFLICT DO NOTHING
	`, charID, req.TargetCharacterID)
	if err != nil {
		logger.Error("add friend failed: %v", err)
		return errResp(9002, "internal error", traceID)
	}

	// 发送通知给目标玩家
	_, err = nk.NotificationsSend(ctx, []runtime.NotificationRequest{
		{
			Code:      3001,
			Content:   map[string]interface{}{"type": "friend_request", "from_id": charID},
			Persistent: true,
			Subject:   "好友请求",
		},
	}, []string{req.TargetCharacterID})
	if err != nil {
		logger.Error("send friend notification failed: %v", err)
	}

	return okResp(map[string]interface{}{
		"success":     true,
		"target_name": targetName,
		"message":     "好友请求已发送",
	}, traceID)
}

func removeFriend(ctx context.Context, logger runtime.Logger, db *sql.DB, nk runtime.NakamaModule, payload string) (string, error) {
	traceID := newTraceID()
	uid := userIDFromCtx(ctx)
	if uid == "" {
		return errResp(1001, "missing token", traceID)
	}

	var req removeFriendReq
	if err := json.Unmarshal([]byte(payload), &req); err != nil {
		return errResp(2001, "invalid payload", traceID)
	}

	// 获取角色ID
	var charID string
	err := hhdbPool.QueryRow(ctx, `
		SELECT id FROM characters WHERE player_id = $1 AND status = 'active'
		ORDER BY created_at DESC LIMIT 1
	`, uid).Scan(&charID)
	if err != nil {
		return errResp(4002, "character not found", traceID)
	}

	// 删除好友关系
	_, err = hhdbPool.Exec(ctx, `
		UPDATE social_relations
		SET status = 'dissolved', dissolved_at = NOW()
		WHERE ((character_a_id = $1 AND character_b_id = $2)
		       OR (character_a_id = $2 AND character_b_id = $1))
		AND relation_type = 'friend' AND status = 'active'
	`, charID, req.FriendID)
	if err != nil {
		logger.Error("remove friend failed: %v", err)
		return errResp(9002, "internal error", traceID)
	}

	return okResp(map[string]interface{}{
		"success": true,
		"message": "好友已删除",
	}, traceID)
}

func getFriends(ctx context.Context, logger runtime.Logger, db *sql.DB, nk runtime.NakamaModule, payload string) (string, error) {
	traceID := newTraceID()
	uid := userIDFromCtx(ctx)
	if uid == "" {
		return errResp(1001, "missing token", traceID)
	}

	var req getFriendsReq
	if err := json.Unmarshal([]byte(payload), &req); err != nil {
		return errResp(2001, "invalid payload", traceID)
	}

	// 查询好友列表
	rows, err := hhdbPool.Query(ctx, `
		SELECT c.id, c.name, c.race_id, c.realm_tier, c.last_online_at, sr.intimacy, sr.status
		FROM social_relations sr
		JOIN characters c ON (
			CASE WHEN sr.character_a_id = $1 THEN sr.character_b_id
			     ELSE sr.character_a_id END
		) = c.id
		WHERE (sr.character_a_id = $1 OR sr.character_b_id = $1)
		AND sr.relation_type = 'friend' AND sr.status = 'active'
		ORDER BY sr.intimacy DESC
	`, req.CharacterID)
	if err != nil {
		logger.Error("get friends failed: %v", err)
		return errResp(9002, "internal error", traceID)
	}
	defer rows.Close()

	var friends []friendData
	for rows.Next() {
		var f friendData
		if err := rows.Scan(&f.CharacterID, &f.Name, &f.RaceID, &f.RealmTier,
			&f.LastSeen, &f.Intimacy, &f.Status); err != nil {
			continue
		}
		// 简单判断在线状态（5分钟内有活动）
		f.IsOnline = time.Since(f.LastSeen) < 5*time.Minute
		friends = append(friends, f)
	}

	return okResp(map[string]interface{}{
		"friends": friends,
		"count":   len(friends),
	}, traceID)
}

func acceptFriend(ctx context.Context, logger runtime.Logger, db *sql.DB, nk runtime.NakamaModule, payload string) (string, error) {
	traceID := newTraceID()
	uid := userIDFromCtx(ctx)
	if uid == "" {
		return errResp(1001, "missing token", traceID)
	}

	var req acceptFriendReq
	if err := json.Unmarshal([]byte(payload), &req); err != nil {
		return errResp(2001, "invalid payload", traceID)
	}

	// 简化版：接受好友请求
	logger.Info("Accept friend request: relation_id=%s", req.RelationID)

	return okResp(map[string]interface{}{
		"success": true,
		"message": "好友请求已接受",
	}, traceID)
}

func createParty(ctx context.Context, logger runtime.Logger, db *sql.DB, nk runtime.NakamaModule, payload string) (string, error) {
	traceID := newTraceID()
	uid := userIDFromCtx(ctx)
	if uid == "" {
		return errResp(1001, "missing token", traceID)
	}

	var req createPartyReq
	if err := json.Unmarshal([]byte(payload), &req); err != nil {
		return errResp(2001, "invalid payload", traceID)
	}

	// 获取队长角色ID
	var charID string
	var charName string
	var worldTier, realmTier int32
	err := hhdbPool.QueryRow(ctx, `
		SELECT id, name, world_tier, realm_tier
		FROM characters WHERE player_id = $1 AND status = 'active'
		ORDER BY created_at DESC LIMIT 1
	`, uid).Scan(&charID, &charName, &worldTier, &realmTier)
	if err != nil {
		return errResp(4002, "character not found", traceID)
	}

	// 创建队伍（简化版，实际应存储到数据库）
	partyID := genUUID()

	return okResp(partyData{
		PartyID:    partyID,
		LeaderID:   charID,
		LeaderName: charName,
		MaxMembers: req.MaxMembers,
		PartyName:  req.PartyName,
		WorldTier:  worldTier,
		RealmTier:  realmTier,
		Status:     "forming",
		CreatedAt:  time.Now(),
	}, traceID)
}

func joinParty(ctx context.Context, logger runtime.Logger, db *sql.DB, nk runtime.NakamaModule, payload string) (string, error) {
	traceID := newTraceID()
	uid := userIDFromCtx(ctx)
	if uid == "" {
		return errResp(1001, "missing token", traceID)
	}

	var req joinPartyReq
	if err := json.Unmarshal([]byte(payload), &req); err != nil {
		return errResp(2001, "invalid payload", traceID)
	}

	// 获取角色信息
	var charID string
	var charName string
	var worldTier, realmTier int32
	err := hhdbPool.QueryRow(ctx, `
		SELECT id, name, world_tier, realm_tier
		FROM characters WHERE player_id = $1 AND status = 'active'
		ORDER BY created_at DESC LIMIT 1
	`, uid).Scan(&charID, &charName, &worldTier, &realmTier)
	if err != nil {
		return errResp(4002, "character not found", traceID)
	}

	// 简化版：加入队伍
	logger.Info("Join party: party=%s player=%s", req.PartyID, charName)

	return okResp(map[string]interface{}{
		"success":      true,
		"party_id":     req.PartyID,
		"character_id": charID,
		"character_name": charName,
		"message":      "成功加入队伍",
	}, traceID)
}

func leaveParty(ctx context.Context, logger runtime.Logger, db *sql.DB, nk runtime.NakamaModule, payload string) (string, error) {
	traceID := newTraceID()
	uid := userIDFromCtx(ctx)
	if uid == "" {
		return errResp(1001, "missing token", traceID)
	}

	var req leavePartyReq
	if err := json.Unmarshal([]byte(payload), &req); err != nil {
		return errResp(2001, "invalid payload", traceID)
	}

	// 简化版：离开队伍
	logger.Info("Leave party: party=%s", req.PartyID)

	return okResp(map[string]interface{}{
		"success": true,
		"message": "已离开队伍",
	}, traceID)
}

func getPartyInfo(ctx context.Context, logger runtime.Logger, db *sql.DB, nk runtime.NakamaModule, payload string) (string, error) {
	traceID := newTraceID()

	var req getPartyInfoReq
	if err := json.Unmarshal([]byte(payload), &req); err != nil {
		return errResp(2001, "invalid payload", traceID)
	}

	// 简化版：返回队伍信息
	return okResp(map[string]interface{}{
		"party_id":   req.PartyID,
		"members":    []partyMemberData{},
		"max_members": 5,
		"status":     "forming",
	}, traceID)
}