package dto

import (
	"slices"
	"strings"

	"gitlab.com/mbugroup/lti-api.git/internal/entities"
	"gitlab.com/mbugroup/lti-api.git/internal/utils"
)

// === CONSTANTS ===
const (
	HPPGroupPengeluaran = "HPP dan Pengeluaran"
	HPPGroupBahanBaku   = "HPP dan Bahan Baku"
	HPPLabelOverhead    = "Pengeluaran Overhead"
	HPPLabelEkspedisi   = "Beban Ekspedisi"
	HPPSummaryLabel     = "HPP"

	PLSalesTypeChicken = "Penjualan Ayam Besar"
	PLSalesTypeEgg     = "Penjualan Telur"

	PLItemTypeSapronak  = "Pembelian Sapronak"
	PLItemTypeOverhead  = "Pengeluaran Overhead"
	PLItemTypeEkspedisi = "Beban Ekspedisi"

	PLSummaryLabelGrossProfit = "LABA RUGI BRUTTO"
	PLSummaryLabelSubTotal    = "SUB TOTAL"
	PLSummaryLabelNetProfit   = "LABA RUGI NETTO"

	PurchaseLabelPrefix = "Pembelian "
)

// === CONTEXT STRUCTS ===

type CalculationContext struct {
	TotalPopulation     float64
	TotalWeightProduced float64
	TotalEggWeightKg    float64
	TotalDepletion      float64
	TotalWeightSold     float64
	ActualPopulation    float64
}

type ClosingKeuanganInput struct {
	ProjectFlockCategory string
	PurchaseItems        []entities.PurchaseItem
	Budgets              []entities.ProjectBudget
	Realizations         []entities.ExpenseRealization
	DeliveryProducts     []entities.MarketingDeliveryProduct
	Chickins             []entities.ProjectChickin
	TotalWeightProduced  float64
	TotalEggWeightKg     float64
	TotalDepletion       float64
}

// === BASE METRICS ===

type FinancialMetrics struct {
	RpPerBird float64 `json:"rp_per_bird"`
	RpPerKg   float64 `json:"rp_per_kg"`
	Amount    float64 `json:"amount"`
}

type Comparison struct {
	Budgeting   FinancialMetrics `json:"budgeting"`
	Realization FinancialMetrics `json:"realization"`
}

// === HPP PURCHASES PACKAGE ===

type HppItem struct {
	Type string `json:"type"`
	Comparison
}

type HppGroup struct {
	GroupName string    `json:"group_name"`
	Data      []HppItem `json:"data"`
}

type SummaryHpp struct {
	Label            string            `json:"label"`
	Budgeting        FinancialMetrics  `json:"budgeting"`
	Realization      FinancialMetrics  `json:"realization"`
	EggBudgeting     *FinancialMetrics `json:"egg_budgeting,omitempty"`
	EggRealization   *FinancialMetrics `json:"egg_realization,omitempty"`
}

type HppPurchasesSection struct {
	Hpp        []HppGroup `json:"hpp"`
	SummaryHpp SummaryHpp `json:"summary_hpp"`
}

// === PROFIT LOSS PACKAGE ===

type PLItem struct {
	Type string `json:"type"`
	FinancialMetrics
}

type PLSummaryItem struct {
	Label string `json:"label"`
	FinancialMetrics
}

type PLSummaryGroup struct {
	GrossProfit PLSummaryItem `json:"gross_profit"`
	SubTotal    PLSummaryItem `json:"sub_total"`
	NetProfit   PLSummaryItem `json:"net_profit"`
}

type ProfitLossData struct {
	Penjualan []PLItem       `json:"penjualan"`
	Pembelian []PLItem       `json:"pembelian"`
	Overhead  PLItem         `json:"overhead"`
	Ekspedisi PLItem         `json:"ekspedisi"`
	Summary   PLSummaryGroup `json:"summary"`
}

type ProfitLossSection struct {
	Data ProfitLossData `json:"data"`
}

// === RESPONSE DTO (ROOT) ===

type ReportResponse struct {
	HppPurchases HppPurchasesSection `json:"hpp_purchases"`
	ProfitLoss   ProfitLossSection   `json:"profit_loss"`
}

// === MAPPER FUNCTIONS ===

func ToFinancialMetrics(rpPerBird, rpPerKg, amount float64) FinancialMetrics {
	return FinancialMetrics{
		RpPerBird: rpPerBird,
		RpPerKg:   rpPerKg,
		Amount:    amount,
	}
}

func ToComparison(budgeting, realization FinancialMetrics) Comparison {
	return Comparison{
		Budgeting:   budgeting,
		Realization: realization,
	}
}

// === HPP PENGELUARAN (from Purchase Items) ===

func getFlagLabel(flagType utils.FlagType) string {
	return PurchaseLabelPrefix + string(flagType)
}

func buildHppItemsByPurchaseFlags(purchaseItems []entities.PurchaseItem, ctx CalculationContext) []HppItem {
	flags := []utils.FlagType{
		utils.FlagDOC, utils.FlagPullet, utils.FlagLayer, utils.FlagPakan,
		utils.FlagPreStarter, utils.FlagStarter, utils.FlagFinisher,
		utils.FlagOVK, utils.FlagObat, utils.FlagVitamin, utils.FlagKimia,
	}

	items := []HppItem{}
	seenFlags := make(map[utils.FlagType]bool)

	for _, item := range purchaseItems {
		if item.Product == nil || len(item.Product.Flags) == 0 {
			continue
		}

		for _, flag := range item.Product.Flags {
			flagType := utils.FlagType(flag.Name)

			if slices.Contains(flags, flagType) && !seenFlags[flagType] {
				amount := sumPurchasesByFlag(purchaseItems, flagType)
				rpPerBird, rpPerKg := calculatePerUnitMetrics(amount, ctx.TotalPopulation, ctx.TotalWeightProduced)

				items = append(items, HppItem{
					Type: getFlagLabel(flagType),
					Comparison: ToComparison(
						ToFinancialMetrics(rpPerBird, rpPerKg, amount),
						ToFinancialMetrics(rpPerBird, rpPerKg, amount),
					),
				})
				seenFlags[flagType] = true
			}
		}
	}

	return items
}

// === HPP BAHAN BAKU (from ProjectBudget + ExpenseRealization) ===

func createHppOverheadItem(budgetAmount, realizationAmount float64, ctx CalculationContext) HppItem {
	budgetRpPerBird, budgetRpPerKg := calculatePerUnitMetrics(budgetAmount, ctx.TotalPopulation, ctx.TotalWeightProduced)
	realizationRpPerBird, realizationRpPerKg := calculatePerUnitMetrics(realizationAmount, ctx.TotalPopulation, ctx.TotalWeightProduced)

	return HppItem{
		Type: HPPLabelOverhead,
		Comparison: ToComparison(
			ToFinancialMetrics(budgetRpPerBird, budgetRpPerKg, budgetAmount),
			ToFinancialMetrics(realizationRpPerBird, realizationRpPerKg, realizationAmount),
		),
	}
}

func createHppEkspedisiItem(ekspedisiAmount float64, ctx CalculationContext) HppItem {
	ekspedisiRpPerBird, ekspedisiRpPerKg := calculatePerUnitMetrics(ekspedisiAmount, ctx.TotalPopulation, ctx.TotalWeightProduced)

	return HppItem{
		Type: HPPLabelEkspedisi,
		Comparison: ToComparison(
			ToFinancialMetrics(ekspedisiRpPerBird, ekspedisiRpPerKg, ekspedisiAmount),
			ToFinancialMetrics(ekspedisiRpPerBird, ekspedisiRpPerKg, ekspedisiAmount),
		),
	}
}

func ToHppBahanBakuGroup(budgets []entities.ProjectBudget, realizations []entities.ExpenseRealization, ctx CalculationContext) HppGroup {
	items := []HppItem{}

	budgetAmount := sumBudgetsByFilter(budgets, func(*entities.ProjectBudget) bool { return true })
	realizationAmount := getOperationalExpenses(realizations)

	if budgetAmount > 0 || realizationAmount > 0 {
		items = append(items, createHppOverheadItem(budgetAmount, realizationAmount, ctx))
	}

	ekspedisiAmount := sumRealizationsByFilter(realizations, filterRealizationByNonstockFlag(utils.FlagEkspedisi))
	items = append(items, createHppEkspedisiItem(ekspedisiAmount, ctx))

	return HppGroup{
		GroupName: HPPGroupBahanBaku,
		Data:      items,
	}
}

// === HPP SUMMARY ===

func ToSummaryHpp(label string, purchaseItems []entities.PurchaseItem, budgets []entities.ProjectBudget, realizations []entities.ExpenseRealization, projectFlockCategory string, ctx CalculationContext) SummaryHpp {
	purchaseTotal := sumPurchaseTotal(purchaseItems)
	budgetTotal := sumBudgetsByFilter(budgets, func(*entities.ProjectBudget) bool { return true })
	totalBudget := purchaseTotal + budgetTotal

	totalRealization := sumRealizationsByFilter(realizations, func(*entities.ExpenseRealization) bool { return true })

	budgetRpPerBird, budgetRpPerKg := calculatePerUnitMetrics(totalBudget, ctx.TotalPopulation, ctx.TotalWeightProduced)
	realizationRpPerBird, realizationRpPerKg := calculatePerUnitMetrics(totalRealization, ctx.TotalPopulation, ctx.TotalWeightProduced)

	summary := SummaryHpp{
		Label:       label,
		Budgeting:   ToFinancialMetrics(budgetRpPerBird, budgetRpPerKg, totalBudget),
		Realization: ToFinancialMetrics(realizationRpPerBird, realizationRpPerKg, totalRealization),
	}

	if projectFlockCategory == string(utils.ProjectFlockCategoryLaying) && ctx.TotalEggWeightKg > 0 {
		budgetEggRpPerKg, _ := calculatePerUnitMetrics(totalBudget, 0, ctx.TotalEggWeightKg)
		realizationEggRpPerKg, _ := calculatePerUnitMetrics(totalRealization, 0, ctx.TotalEggWeightKg)

		summary.EggBudgeting = &FinancialMetrics{
			RpPerBird: 0,
			RpPerKg:   budgetEggRpPerKg,
			Amount:    totalBudget,
		}
		summary.EggRealization = &FinancialMetrics{
			RpPerBird: 0,
			RpPerKg:   realizationEggRpPerKg,
			Amount:    totalRealization,
		}
	}

	return summary
}

func ToHppPurchasesSection(purchaseItems []entities.PurchaseItem, budgets []entities.ProjectBudget, realizations []entities.ExpenseRealization, projectFlockCategory string, ctx CalculationContext) HppPurchasesSection {
	hppGroups := []HppGroup{
		{
			GroupName: HPPGroupPengeluaran,
			Data:      buildHppItemsByPurchaseFlags(purchaseItems, ctx),
		},
		ToHppBahanBakuGroup(budgets, realizations, ctx),
	}

	summaryHpp := ToSummaryHpp(HPPSummaryLabel, purchaseItems, budgets, realizations, projectFlockCategory, ctx)

	return HppPurchasesSection{
		Hpp:        hppGroups,
		SummaryHpp: summaryHpp,
	}
}

// === PROFIT & LOSS ===

func ToPLItem(itemType string, metrics FinancialMetrics) PLItem {
	return PLItem{
		Type:             itemType,
		FinancialMetrics: metrics,
	}
}

func ToPLSummaryItem(label string, metrics FinancialMetrics) PLSummaryItem {
	return PLSummaryItem{
		Label:            label,
		FinancialMetrics: metrics,
	}
}

func createPLItemWithMetrics(itemType string, amount float64, ctx CalculationContext) PLItem {
	rpPerBird, rpPerKg := calculatePerUnitMetrics(amount, ctx.ActualPopulation, ctx.TotalWeightProduced)
	return ToPLItem(itemType, ToFinancialMetrics(rpPerBird, rpPerKg, amount))
}

func sumPLItems(items []PLItem) (totalAmount, totalPerBird float64) {
	for _, item := range items {
		totalAmount += item.Amount
		totalPerBird += item.RpPerBird
	}
	return
}

func createPenjualanItem(salesType string, amount float64, ctx CalculationContext) PLItem {
	rpPerBird, rpPerKg := calculatePerUnitMetrics(amount, ctx.ActualPopulation, ctx.TotalWeightSold)
	return ToPLItem(salesType, ToFinancialMetrics(rpPerBird, rpPerKg, amount))
}

func ToPenjualanItems(projectFlockCategory string, deliveryProducts []entities.MarketingDeliveryProduct, ctx CalculationContext) []PLItem {
	items := []PLItem{}

	categorized := categorizeDeliveriesBySalesType(deliveryProducts)

	if projectFlockCategory == string(utils.ProjectFlockCategoryLaying) {
		ayamAmount := sumDeliveriesByCategory(categorized[PLSalesTypeChicken])
		telurAmount := sumDeliveriesByCategory(categorized[PLSalesTypeEgg])

		items = append(items, createPenjualanItem(PLSalesTypeChicken, ayamAmount, ctx))
		items = append(items, createPenjualanItem(PLSalesTypeEgg, telurAmount, ctx))
	} else {
		ayamAmount := sumDeliveriesByCategory(categorized[PLSalesTypeChicken])
		items = append(items, createPenjualanItem(PLSalesTypeChicken, ayamAmount, ctx))
	}

	return items
}

func ToPembelianItems(purchases []entities.PurchaseItem, realizations []entities.ExpenseRealization, ctx CalculationContext) []PLItem {
	purchaseAmount := sumPurchaseTotal(purchases)

	return []PLItem{
		createPLItemWithMetrics(PLItemTypeSapronak, purchaseAmount, ctx),
	}
}

func ToOverheadItems(realizations []entities.ExpenseRealization, ctx CalculationContext) []PLItem {
	realizationAmount := getOperationalExpenses(realizations)
	return []PLItem{
		createPLItemWithMetrics(PLItemTypeOverhead, realizationAmount, ctx),
	}
}

func ToEkspedisiItems(realizations []entities.ExpenseRealization, ctx CalculationContext) []PLItem {
	amount := sumRealizationsByFilter(realizations, filterRealizationByNonstockFlag(utils.FlagEkspedisi))
	return []PLItem{
		createPLItemWithMetrics(PLItemTypeEkspedisi, amount, ctx),
	}
}

func ToPLSummaryGroup(penjualanItems, pembelianItems, overheadItems, ekspedisiItems []PLItem) PLSummaryGroup {
	totalPenjualan, totalPenjualanPerBird := sumPLItems(penjualanItems)
	totalPembelian, totalPembelianPerBird := sumPLItems(pembelianItems)
	totalOverhead, totalOverheadPerBird := sumPLItems(overheadItems)
	totalEkspedisi, totalEkspedisiPerBird := sumPLItems(ekspedisiItems)

	grossProfit := totalPenjualan - totalPembelian
	grossProfitPerBird := totalPenjualanPerBird - totalPembelianPerBird

	totalOtherExpenses := totalOverhead + totalEkspedisi
	totalOtherExpensesPerBird := totalOverheadPerBird + totalEkspedisiPerBird

	netProfit := grossProfit - totalOtherExpenses
	netProfitPerBird := grossProfitPerBird - totalOtherExpensesPerBird

	return PLSummaryGroup{
		GrossProfit: ToPLSummaryItem(PLSummaryLabelGrossProfit, ToFinancialMetrics(grossProfitPerBird, 0, grossProfit)),
		SubTotal:    ToPLSummaryItem(PLSummaryLabelSubTotal, ToFinancialMetrics(totalOtherExpensesPerBird, 0, totalOtherExpenses)),
		NetProfit:   ToPLSummaryItem(PLSummaryLabelNetProfit, ToFinancialMetrics(netProfitPerBird, 0, netProfit)),
	}
}

func ToProfitLossData(penjualanItems, pembelianItems, overheadItems, ekspedisiItems []PLItem) ProfitLossData {
	summary := ToPLSummaryGroup(penjualanItems, pembelianItems, overheadItems, ekspedisiItems)

	totalOverhead := aggregatePLItems(overheadItems, PLItemTypeOverhead)
	totalEkspedisi := aggregatePLItems(ekspedisiItems, PLItemTypeEkspedisi)

	return ProfitLossData{
		Penjualan: penjualanItems,
		Pembelian: pembelianItems,
		Overhead:  totalOverhead,
		Ekspedisi: totalEkspedisi,
		Summary:   summary,
	}
}

func ToProfitLossSection(penjualanItems, pembelianItems, overheadItems, ekspedisiItems []PLItem) ProfitLossSection {
	return ProfitLossSection{
		Data: ToProfitLossData(penjualanItems, pembelianItems, overheadItems, ekspedisiItems),
	}
}

func aggregatePLItems(items []PLItem, label string) PLItem {
	totalAmount, totalPerBird := sumPLItems(items)
	return ToPLItem(label, ToFinancialMetrics(totalPerBird, 0, totalAmount))
}

func ToReportResponse(hppPurchases HppPurchasesSection, profitLoss ProfitLossSection) ReportResponse {
	return ReportResponse{
		HppPurchases: hppPurchases,
		ProfitLoss:   profitLoss,
	}
}

func ToClosingKeuanganReport(input ClosingKeuanganInput) ReportResponse {
	var totalPopulation float64
	var totalWeightSold float64

	for _, chickin := range input.Chickins {
		totalPopulation += chickin.UsageQty
	}

	for _, delivery := range input.DeliveryProducts {
		totalWeightSold += delivery.TotalWeight
	}

	ctx := CalculationContext{
		TotalPopulation:     totalPopulation,
		TotalWeightProduced: input.TotalWeightProduced,
		TotalEggWeightKg:    input.TotalEggWeightKg,
		TotalDepletion:      input.TotalDepletion,
		TotalWeightSold:     totalWeightSold,
		ActualPopulation:    totalPopulation - input.TotalDepletion,
	}

	hppSection := ToHppPurchasesSection(input.PurchaseItems, input.Budgets, input.Realizations, input.ProjectFlockCategory, ctx)
	penjualanItems := ToPenjualanItems(input.ProjectFlockCategory, input.DeliveryProducts, ctx)
	pembelianItems := ToPembelianItems(input.PurchaseItems, input.Realizations, ctx)
	overheadItems := ToOverheadItems(input.Realizations, ctx)
	ekspedisiItems := ToEkspedisiItems(input.Realizations, ctx)
	plSection := ToProfitLossSection(penjualanItems, pembelianItems, overheadItems, ekspedisiItems)

	return ToReportResponse(hppSection, plSection)
}

// === HELPER FUNCTIONS ===

func calculatePerUnitMetrics(amount, totalPopulation, totalWeightSold float64) (rpPerBird, rpPerKg float64) {
	if totalPopulation > 0 {
		rpPerBird = amount / totalPopulation
	}
	if totalWeightSold > 0 {
		rpPerKg = amount / totalWeightSold
	}
	return rpPerBird, rpPerKg
}

func hasProductFlag(flags []entities.Flag, flagType utils.FlagType) bool {
	for _, flag := range flags {
		if strings.ToUpper(flag.Name) == string(flagType) {
			return true
		}
	}
	return false
}

func filterByPurchaseFlag(flagType utils.FlagType) func(*entities.PurchaseItem) bool {
	return func(item *entities.PurchaseItem) bool {
		if item.Product == nil || len(item.Product.Flags) == 0 {
			return false
		}
		return hasProductFlag(item.Product.Flags, flagType)
	}
}

func filterRealizationByNonstockFlag(flagType utils.FlagType) func(*entities.ExpenseRealization) bool {
	return func(realization *entities.ExpenseRealization) bool {
		if realization.ExpenseNonstock == nil || realization.ExpenseNonstock.Nonstock == nil {
			return false
		}
		return hasProductFlag(realization.ExpenseNonstock.Nonstock.Flags, flagType)
	}
}

func filterRealizationExceptFlag(flagType utils.FlagType) func(*entities.ExpenseRealization) bool {
	hasFlag := filterRealizationByNonstockFlag(flagType)
	return func(realization *entities.ExpenseRealization) bool {
		return !hasFlag(realization)
	}
}

func sumByFilter[T any](items []T, extractor func(*T) float64, filter func(*T) bool) float64 {
	amount := 0.0
	for i := range items {
		if filter(&items[i]) {
			amount += extractor(&items[i])
		}
	}
	return amount
}

func sumPurchasesByFilter(purchases []entities.PurchaseItem, filter func(*entities.PurchaseItem) bool) float64 {
	return sumByFilter(purchases, func(p *entities.PurchaseItem) float64 { return p.TotalPrice }, filter)
}

func sumPurchasesByFlag(purchases []entities.PurchaseItem, flagType utils.FlagType) float64 {
	return sumPurchasesByFilter(purchases, filterByPurchaseFlag(flagType))
}

func sumPurchaseTotal(purchases []entities.PurchaseItem) float64 {
	return sumByFilter(purchases, func(p *entities.PurchaseItem) float64 { return p.TotalPrice }, func(*entities.PurchaseItem) bool { return true })
}

func sumBudgetsByFilter(budgets []entities.ProjectBudget, filter func(*entities.ProjectBudget) bool) float64 {
	return sumByFilter(budgets, func(b *entities.ProjectBudget) float64 { return b.Price * b.Qty }, filter)
}

func sumRealizationsByFilter(realizations []entities.ExpenseRealization, filter func(*entities.ExpenseRealization) bool) float64 {
	return sumByFilter(realizations, func(r *entities.ExpenseRealization) float64 { return r.Price * r.Qty }, filter)
}

func getOperationalExpenses(realizations []entities.ExpenseRealization) float64 {
	return sumRealizationsByFilter(realizations, filterRealizationExceptFlag(utils.FlagEkspedisi))
}

func isChickenProductFlag(flagType utils.FlagType) bool {
	switch flagType {
	case utils.FlagDOC, utils.FlagPullet, utils.FlagLayer,
		utils.FlagAyamAfkir, utils.FlagAyamCulling, utils.FlagAyamMati:
		return true
	}
	return false
}

func isEggProductFlag(flagType utils.FlagType) bool {
	switch flagType {
	case utils.FlagTelur, utils.FlagTelurUtuh, utils.FlagTelurPecah,
		utils.FlagTelurPutih, utils.FlagTelurRetak:
		return true
	}
	return false
}

func getSalesTypeFromProductFlags(product *entities.Product) string {
	if product == nil || len(product.Flags) == 0 {
		return PLSalesTypeChicken
	}

	for _, flag := range product.Flags {
		flagType := utils.FlagType(strings.ToUpper(flag.Name))

		if isEggProductFlag(flagType) {
			return PLSalesTypeEgg
		}
		if isChickenProductFlag(flagType) {
			return PLSalesTypeChicken
		}
	}

	return PLSalesTypeChicken
}

func categorizeDeliveriesBySalesType(deliveries []entities.MarketingDeliveryProduct) map[string][]entities.MarketingDeliveryProduct {
	categorized := make(map[string][]entities.MarketingDeliveryProduct)

	for _, delivery := range deliveries {
		product := delivery.MarketingProduct.ProductWarehouse.Product
		salesType := getSalesTypeFromProductFlags(&product)

		categorized[salesType] = append(categorized[salesType], delivery)
	}

	return categorized
}

func sumDeliveriesByCategory(deliveries []entities.MarketingDeliveryProduct) float64 {
	amount := 0.0
	for _, delivery := range deliveries {
		amount += delivery.TotalPrice
	}
	return amount
}