// Package modules - 怪物生成引擎模块
// 对齐GDD-19 怪物图鉴与生成引擎
package modules

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

	"github.com/heroiclabs/nakama-common/runtime"
)

// RegisterMonster 注册怪物相关 RPC。
func RegisterMonster(initializer runtime.Initializer) error {
	rpcs := map[string]func(runtime.Initializer) error{
		"MonsterService/GetMonsterInfo":   getMonsterInfo,
		"MonsterService/GetMonsterList":    getMonsterList,
		"MonsterService/GetMonsterDrops":   getMonsterDrops,
	}
	for path, fn := range rpcs {
		if err := initializer.RegisterRpc(path, fn); err != nil {
			return err
		}
	}
	return nil
}

type getMonsterInfoReq struct {
	MonsterID string `json:"monster_id"`
}

type getMonsterListReq struct {
	WorldTier int32  `json:"world_tier"`
	MonsterType string `json:"monster_type"` // wild/elite/boss
	Page      int32  `json:"page"`
	PageSize  int32  `json:"page_size"`
}

type getMonsterDropsReq struct {
	MonsterID string `json:"monster_id"`
}

type monsterInfoData struct {
	ID          string      `json:"id"`
	Name        string      `json:"name"`
	MonsterType string      `json:"monster_type"` // wild/elite/boss
	WorldTier   int32       `json:"world_tier"`
	RealmTier   int32       `json:"realm_tier"`
	HP          int32       `json:"hp"`
	Attack      int32       `json:"attack"`
	Defense     int32       `json:"defense"`
	Elements    interface{} `json:"elements"`
	Drops       interface{} `json:"drops"`
	SpawnRate   float64     `json:"spawn_rate"`
	IsAggressive bool       `json:"is_aggressive"`
}

type monsterDropData struct {
	ItemID      string  `json:"item_id"`
	ItemName    string  `json:"item_name"`
	DropRate    float64 `json:"drop_rate"`
	MinQuantity int32   `json:"min_quantity"`
	MaxQuantity int32   `json:"max_quantity"`
}

// 怪物模板配置
var monsterTemplates = map[string]monsterInfoData{
	"wild_boar": {
		ID: "wild_boar", Name: "野猪", MonsterType: "wild",
		WorldTier: 1, RealmTier: 1, HP: 100, Attack: 8, Defense: 3,
		Elements: []string{"none"}, SpawnRate: 0.8, IsAggressive: false,
	},
	"wolf": {
		ID: "wolf", Name: "灰狼", MonsterType: "wild",
		WorldTier: 1, RealmTier: 1, HP: 120, Attack: 12, Defense: 5,
		Elements: []string{"none"}, SpawnRate: 0.7, IsAggressive: true,
	},
	"forest_troll": {
		ID: "forest_troll", Name: "森林巨魔", MonsterType: "elite",
		WorldTier: 2, RealmTier: 2, HP: 500, Attack: 35, Defense: 20,
		Elements: []string{"wood"}, SpawnRate: 0.3, IsAggressive: true,
	},
	"fire_spirit": {
		ID: "fire_spirit", Name: "火焰精灵", MonsterType: "elite",
		WorldTier: 3, RealmTier: 3, HP: 800, Attack: 55, Defense: 30,
		Elements: []string{"fire"}, SpawnRate: 0.2, IsAggressive: true,
	},
	"ancient_dragon": {
		ID: "ancient_dragon", Name: "远古巨龙", MonsterType: "boss",
		WorldTier: 5, RealmTier: 6, HP: 50000, Attack: 500, Defense: 300,
		Elements: []string{"fire", "lightning"}, SpawnRate: 0.01, IsAggressive: true,
	},
	"chaos_guardian": {
		ID: "chaos_guardian", Name: "混沌守卫", MonsterType: "boss",
		WorldTier: 6, RealmTier: 8, HP: 200000, Attack: 2000, Defense: 1500,
		Elements: []string{"chaos"}, SpawnRate: 0.005, IsAggressive: true,
	},
}

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

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

	monster, ok := monsterTemplates[req.MonsterID]
	if !ok {
		return errResp(8501, "monster not found", traceID)
	}

	return okResp(monster, traceID)
}

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

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

	if req.Page < 1 {
		req.Page = 1
	}
	if req.PageSize < 1 || req.PageSize > 50 {
		req.PageSize = 20
	}

	// 筛选怪物
	var monsters []monsterInfoData
	for _, m := range monsterTemplates {
		if m.WorldTier == req.WorldTier {
			if req.MonsterType == "" || m.MonsterType == req.MonsterType {
				monsters = append(monsters, m)
			}
		}
	}

	// 分页
	start := (req.Page - 1) * req.PageSize
	end := start + req.PageSize
	if start > len(monsters) {
		monsters = []monsterInfoData{}
	} else if end > len(monsters) {
		monsters = monsters[start:]
	} else {
		monsters = monsters[start:end]
	}

	return okResp(map[string]interface{}{
		"monsters": monsters,
		"count":    len(monsters),
		"page":     req.Page,
	}, traceID)
}

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

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

	// 模拟掉落表
	drops := []monsterDropData{
		{ItemID: "material_hide", ItemName: "兽皮", DropRate: 0.8, MinQuantity: 1, MaxQuantity: 3},
		{ItemID: "material_bone", ItemName: "兽骨", DropRate: 0.6, MinQuantity: 1, MaxQuantity: 2},
		{ItemID: "material_fang", ItemName: "兽牙", DropRate: 0.3, MinQuantity: 1, MaxQuantity: 1},
	}

	return okResp(map[string]interface{}{
		"monster_id": req.MonsterID,
		"drops":      drops,
	}, traceID)
}