package service

import (
	"context"
	"fmt"
	"log"
	"math/rand"

	pb "lunar-tear/server/gen/proto"
	"lunar-tear/server/internal/gametime"
	"lunar-tear/server/internal/masterdata"
	"lunar-tear/server/internal/store"
	"lunar-tear/server/internal/userdata"
)

const partsMaxLevel = int32(15)

var partsDiffTables = []string{
	"IUserParts",
	"IUserConsumableItem",
}

type PartsServiceServer struct {
	pb.UnimplementedPartsServiceServer
	users    store.UserRepository
	sessions store.SessionRepository
	catalog  *masterdata.PartsCatalog
	config   *masterdata.GameConfig
}

func NewPartsServiceServer(users store.UserRepository, sessions store.SessionRepository, catalog *masterdata.PartsCatalog, config *masterdata.GameConfig) *PartsServiceServer {
	return &PartsServiceServer{users: users, sessions: sessions, catalog: catalog, config: config}
}

func (s *PartsServiceServer) Sell(ctx context.Context, req *pb.PartsSellRequest) (*pb.PartsSellResponse, error) {
	log.Printf("[PartsService] Sell: %d part(s)", len(req.UserPartsUuid))

	userId := currentUserId(ctx, s.users, s.sessions)

	oldUser, _ := s.users.SnapshotUser(userId)
	tracker := userdata.NewDeleteTracker().
		Track("IUserParts", oldUser, userdata.SortedPartsRecords, []string{"userId", "userPartsUuid"})

	snapshot, err := s.users.UpdateUser(userId, func(user *store.UserState) {
		totalGold := int32(0)
		for _, uuid := range req.UserPartsUuid {
			part, ok := user.Parts[uuid]
			if !ok {
				log.Printf("[PartsService] Sell: uuid=%s not found, skipping", uuid)
				continue
			}
			if part.IsProtected {
				log.Printf("[PartsService] Sell: uuid=%s is protected, skipping", uuid)
				continue
			}

			partDef, ok := s.catalog.PartsById[part.PartsId]
			if !ok {
				log.Printf("[PartsService] Sell: partsId=%d not in catalog, skipping", part.PartsId)
				continue
			}

			sellFunc, ok := s.catalog.SellPriceByRarity[partDef.RarityType]
			if !ok {
				log.Printf("[PartsService] Sell: no sell price func for rarity=%d, skipping", partDef.RarityType)
				continue
			}

			gold := sellFunc.Evaluate(part.Level)
			totalGold += gold
			delete(user.Parts, uuid)
			log.Printf("[PartsService] Sell: uuid=%s partsId=%d level=%d -> %d gold", uuid, part.PartsId, part.Level, gold)
		}

		if totalGold > 0 {
			user.ConsumableItems[s.config.ConsumableItemIdForGold] += totalGold
			log.Printf("[PartsService] Sell: total gold +%d", totalGold)
		}
	})
	if err != nil {
		return nil, fmt.Errorf("parts sell: %w", err)
	}

	tables := userdata.SelectTables(userdata.FullClientTableMap(snapshot), partsDiffTables)
	diff := tracker.Apply(snapshot, tables)

	return &pb.PartsSellResponse{
		DiffUserData: diff,
	}, nil
}

func (s *PartsServiceServer) Enhance(ctx context.Context, req *pb.PartsEnhanceRequest) (*pb.PartsEnhanceResponse, error) {
	log.Printf("[PartsService] Enhance: uuid=%s", req.UserPartsUuid)

	userId := currentUserId(ctx, s.users, s.sessions)
	nowMillis := gametime.NowMillis()

	isSuccess := false

	snapshot, err := s.users.UpdateUser(userId, func(user *store.UserState) {
		part, ok := user.Parts[req.UserPartsUuid]
		if !ok {
			log.Printf("[PartsService] Enhance: part uuid=%s not found", req.UserPartsUuid)
			return
		}

		if part.Level >= partsMaxLevel {
			log.Printf("[PartsService] Enhance: part uuid=%s already at max level %d", req.UserPartsUuid, part.Level)
			return
		}

		partDef, ok := s.catalog.PartsById[part.PartsId]
		if !ok {
			log.Printf("[PartsService] Enhance: part master id=%d not found", part.PartsId)
			return
		}

		rarity, ok := s.catalog.RarityByRarityType[partDef.RarityType]
		if !ok {
			log.Printf("[PartsService] Enhance: rarity type=%d not found", partDef.RarityType)
			return
		}

		goldCost := int32(0)
		if prices, ok := s.catalog.PriceByGroupAndLevel[rarity.PartsLevelUpPriceGroupId]; ok {
			goldCost = prices[part.Level]
		}

		currentGold := user.ConsumableItems[s.config.ConsumableItemIdForGold]
		if currentGold < goldCost {
			log.Printf("[PartsService] Enhance: insufficient gold have=%d need=%d", currentGold, goldCost)
			return
		}

		user.ConsumableItems[s.config.ConsumableItemIdForGold] -= goldCost

		successRate := int32(1000)
		if rates, ok := s.catalog.RateByGroupAndLevel[rarity.PartsLevelUpRateGroupId]; ok {
			if r, ok := rates[part.Level]; ok {
				successRate = r
			}
		}

		if rand.Intn(1000) < int(successRate) {
			part.Level++
			isSuccess = true
			log.Printf("[PartsService] Enhance: SUCCESS partsId=%d level %d -> %d (rate=%d‰, cost=%d gold)",
				part.PartsId, part.Level-1, part.Level, successRate, goldCost)
		} else {
			log.Printf("[PartsService] Enhance: FAIL partsId=%d stays level %d (rate=%d‰, cost=%d gold)",
				part.PartsId, part.Level, successRate, goldCost)
		}

		part.LatestVersion = nowMillis
		user.Parts[req.UserPartsUuid] = part
	})
	if err != nil {
		return nil, fmt.Errorf("parts enhance: %w", err)
	}

	tables := userdata.FullClientTableMap(snapshot)
	diff := userdata.BuildDiffFromTables(userdata.SelectTables(tables, partsDiffTables))

	return &pb.PartsEnhanceResponse{
		IsSuccess:    isSuccess,
		DiffUserData: diff,
	}, nil
}

func (s *PartsServiceServer) ReplacePreset(ctx context.Context, req *pb.PartsReplacePresetRequest) (*pb.PartsReplacePresetResponse, error) {
	log.Printf("[PartsService] ReplacePreset: preset=%d uuids=[%s, %s, %s]",
		req.UserPartsPresetNumber, req.UserPartsUuid01, req.UserPartsUuid02, req.UserPartsUuid03)

	userId := currentUserId(ctx, s.users, s.sessions)
	nowMillis := gametime.NowMillis()

	snapshot, err := s.users.UpdateUser(userId, func(user *store.UserState) {
		preset := user.PartsPresets[req.UserPartsPresetNumber]
		preset.UserPartsPresetNumber = req.UserPartsPresetNumber
		preset.UserPartsUuid01 = req.UserPartsUuid01
		preset.UserPartsUuid02 = req.UserPartsUuid02
		preset.UserPartsUuid03 = req.UserPartsUuid03
		preset.LatestVersion = nowMillis
		user.PartsPresets[req.UserPartsPresetNumber] = preset
	})
	if err != nil {
		return nil, fmt.Errorf("parts replace preset: %w", err)
	}

	tables := userdata.FullClientTableMap(snapshot)
	diff := userdata.BuildDiffFromTables(userdata.SelectTables(tables, []string{"IUserPartsPreset"}))

	return &pb.PartsReplacePresetResponse{
		DiffUserData: diff,
	}, nil
}