package gameserver

import (
	"fmt"
	"math/rand/v2"
	"sort"

	"gac-hkrpg-go/internal/common"
	pb "gac-hkrpg-go/protocol/proto"
	"google.golang.org/protobuf/proto"
)

// cwGenerateSupplyOffer follows the Supply option factory in the reference
// executable identified in docs/cw-route-continuation-audit.md. The protocol
// envelope comes from the native capture; role and equipment IDs must also be
// present in this client's captured data.
func cwGenerateSupplyOffer(c *common.CurrencyWarsCatalog, run *pb.MPIMAEMCEFH) (*pb.IAKEDFLIOFD, error) {
	stage, _ := cwStage(run)
	if stage == nil || stage.DCAHJELNJNP == 0 {
		return nil, fmt.Errorf("CW Supply chapter missing")
	}
	runtime, err := cwBonfireRuntime(c, run)
	if err != nil {
		return nil, err
	}
	return cwGenerateSupplyOfferWithRules(c, run, runtime.Rules)
}

func cwGenerateSupplyOfferWithRules(c *common.CurrencyWarsCatalog, run *pb.MPIMAEMCEFH, rules map[string]uint32) (*pb.IAKEDFLIOFD, error) {
	stage, _ := cwStage(run)
	if stage == nil || stage.DCAHJELNJNP == 0 {
		return nil, fmt.Errorf("CW Supply chapter missing")
	}
	// Box modifies a different part of the selection flow; do not silently
	// grant an ordinary selection if the corresponding action is not mapped.
	if rules["SupplyBox"] != 0 {
		return nil, fmt.Errorf("CW SupplyBox action is not mapped")
	}
	count, err := c.IntegerRule("GridFight_BaseSupplyRoleNum")
	// gfFxHProjectRunState projects ExtraSupplyOption into the field added by
	// gfPendingFillSupplyOptions to the Client's captured base count.
	if err != nil || count <= 0 || uint64(count)+uint64(rules["ExtraSupplyOption"]) > uint64(len(c.CapturedRoles)) {
		return nil, fmt.Errorf("CW Supply option count invalid")
	}
	count += int64(rules["ExtraSupplyOption"])
	star := rules["SupplyStar"]
	if star == 0 {
		star = 1
	} // gfPendingSupplyOf clamps this rule to one.
	category := "Basic"
	if rules["SupplyEmblems"] != 0 {
		category = "Emblem"
	} else if stage.DCAHJELNJNP >= 3 {
		category = "Craftable"
	}
	recipes, err := common.LoadCurrencyWarsOrbRecipes()
	if err != nil {
		return nil, err
	}
	gear, err := common.LoadCurrencyWarsEquipment(c)
	if err != nil {
		return nil, err
	}
	var equipment []uint32
	for _, item := range recipes.Equipment {
		if item.Category == category {
			if _, ok := gear[item.ID]; ok {
				equipment = append(equipment, item.ID)
			}
		}
	}
	if len(equipment) == 0 {
		return nil, fmt.Errorf("CW Supply equipment category %s is empty", category)
	}
	sort.Slice(equipment, func(i, j int) bool { return equipment[i] < equipment[j] })
	pool, err := c.NewCapturedCardPool()
	if err != nil {
		return nil, err
	}
	byRarity := make(map[uint32][]uint32)
	for id, item := range pool.Roles {
		if item.Disabled || item.Remaining == 0 {
			continue
		}
		if _, err := c.CapturedRoleVariant(id, star); err != nil {
			continue
		}
		byRarity[item.Rarity] = append(byRarity[item.Rarity], id)
	}
	for _, ids := range byRarity {
		sort.Slice(ids, func(i, j int) bool { return ids[i] < ids[j] })
	}
	entries, err := cwNodeTransitions(c)
	if err != nil {
		return nil, err
	}
	var offer *pb.IAKEDFLIOFD
	for _, entry := range entries {
		pending := new(pb.CHCHAJIANIM)
		if err := proto.Unmarshal(entry.RoundWire, pending); err != nil {
			return nil, err
		}
		if captured := pending.GetFIKAGBAEOAP(); captured != nil {
			candidate := proto.Clone(captured).(*pb.IAKEDFLIOFD)
			candidate.MFBAKLCBPCJ = nil
			if offer != nil && !proto.Equal(offer, candidate) {
				return nil, fmt.Errorf("CW Supply envelopes differ")
			}
			offer = candidate
		}
	}
	if offer == nil {
		return nil, fmt.Errorf("CW Supply envelope not captured")
	}
	used := map[uint32]bool{}
	for i := int64(0); i < int64(count); i++ {
		var id uint32
		for attempt := 0; attempt < 8; attempt++ {
			rarity := rules["SupplyRarity"]
			if rarity == 0 {
				rarity = min(uint32(rand.IntN(int(stage.DCAHJELNJNP+2)))+1, uint32(5))
			}
			// gfPoolRandomRoleFiltered searches the requested rarity first,
			// then neighbouring rarity buckets at increasing distance.
			for distance := uint32(0); distance < 5 && id == 0; distance++ {
				for _, candidate := range []int64{int64(rarity) - int64(distance), int64(rarity) + int64(distance)} {
					if candidate < 1 || candidate > 5 {
						continue
					}
					ids := byRarity[uint32(candidate)]
					if len(ids) != 0 {
						id = ids[rand.IntN(len(ids))]
						break
					}
				}
			}
			if id != 0 && !used[id] {
				break
			}
			id = 0
		}
		if id == 0 {
			continue
		}
		used[id] = true
		item := equipment[rand.IntN(len(equipment))]
		offer.MFBAKLCBPCJ = append(offer.MFBAKLCBPCJ, &pb.NBGDEFLFLMI{RoleId: id, OPPFPECOBEF: &pb.BCCONKJHDJL{FKKGLFOHGGA: pb.MJJIFGINJAJ_MJJIFGINJAJ_BDPIMPJOJBK, FNLMKJLKLFH: id, Num: 1, DisplayValue: &pb.AOHKKFHDALO{NEBNJDMFELO: &pb.AOHKKFHDALO_RoleStar{RoleStar: star}}}, GridFightItemList: []uint32{item}, DHLBEFLOOPM: []*pb.BCCONKJHDJL{{FKKGLFOHGGA: pb.MJJIFGINJAJ_MJJIFGINJAJ_NLFCABFPJHD, FNLMKJLKLFH: item, Num: 1}}})
	}
	if offer.DAEMEBCKHIK == 0 || uint64(len(offer.MFBAKLCBPCJ)) < uint64(offer.DAEMEBCKHIK) {
		return nil, fmt.Errorf("CW Supply has too few valid role options")
	}
	chance, item := rules["SupplyEquipChance"], rules["SupplyEquip"]
	if chance > 100 {
		return nil, fmt.Errorf("CW Supply equipment chance invalid")
	}
	if chance != 0 && item != 0 && stage.DCAHJELNJNP >= rules["SupplyEquipChapter"] {
		if _, ok := gear[item]; !ok {
			return nil, fmt.Errorf("CW Supply bonus equipment %d is not captured", item)
		}
		if uint32(rand.IntN(100)) < chance {
			choice := offer.MFBAKLCBPCJ[rand.IntN(len(offer.MFBAKLCBPCJ))]
			choice.GridFightItemList[0] = item
			choice.DHLBEFLOOPM[0].FNLMKJLKLFH = item
		}
	}
	return offer, nil
}