package handler

import (
	"net/http"
	"spend-sparrow/internal/handler/middleware"
	"spend-sparrow/internal/service"
	tr "spend-sparrow/internal/template/transaction_recurring"
	t "spend-sparrow/internal/template/treasurechest"
	"spend-sparrow/internal/types"
	"spend-sparrow/internal/utils"

	"github.com/a-h/templ"
	"github.com/google/uuid"
)

type TreasureChest interface {
	Handle(router *http.ServeMux)
}

type TreasureChestImpl struct {
	s                    service.TreasureChest
	transactionRecurring service.TransactionRecurring
	r                    *Render
}

func NewTreasureChest(s service.TreasureChest, transactionRecurring service.TransactionRecurring, r *Render) TreasureChest {
	return TreasureChestImpl{
		s:                    s,
		transactionRecurring: transactionRecurring,
		r:                    r,
	}
}

func (h TreasureChestImpl) Handle(r *http.ServeMux) {
	r.Handle("GET /treasurechest", h.handleTreasureChestPage())
	r.Handle("GET /treasurechest/{id}", h.handleTreasureChestItemComp())
	r.Handle("POST /treasurechest/{id}", h.handleUpdateTreasureChest())
	r.Handle("DELETE /treasurechest/{id}", h.handleDeleteTreasureChest())
}

func (h TreasureChestImpl) handleTreasureChestPage() http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		user := middleware.GetUser(r)
		if user == nil {
			utils.DoRedirect(w, r, "/auth/signin")
			return
		}

		treasureChests, err := h.s.GetAll(user)
		if err != nil {
			handleError(w, r, err)
			return
		}

		transactionsRecurring, err := h.transactionRecurring.GetAll(user)
		if err != nil {
			handleError(w, r, err)
			return
		}

		monthlySums := h.calculateMonthlySums(treasureChests, transactionsRecurring)

		comp := t.TreasureChest(treasureChests, monthlySums)
		h.r.RenderLayout(r, w, comp, user)
	}
}

func (h TreasureChestImpl) handleTreasureChestItemComp() http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		user := middleware.GetUser(r)
		if user == nil {
			utils.DoRedirect(w, r, "/auth/signin")
			return
		}

		treasureChests, err := h.s.GetAll(user)
		if err != nil {
			handleError(w, r, err)
			return
		}

		id := r.PathValue("id")
		if id == "new" {
			comp := t.EditTreasureChest(nil, treasureChests, nil)
			h.r.Render(r, w, comp)
			return
		}

		treasureChest, err := h.s.Get(user, id)
		if err != nil {
			handleError(w, r, err)
			return
		}

		transactionsRecurring, err := h.transactionRecurring.GetAllByTreasureChest(user, treasureChest.Id.String())
		if err != nil {
			handleError(w, r, err)
			return
		}
		transactionsRec := tr.TransactionRecurringItems(transactionsRecurring, "", "", treasureChest.Id.String())

		var comp templ.Component
		if r.URL.Query().Get("edit") == "true" {
			comp = t.EditTreasureChest(treasureChest, treasureChests, transactionsRec)
		} else {
			monthlySums := h.calculateMonthlySums(treasureChests, transactionsRecurring)
			comp = t.TreasureChestItem(treasureChest, monthlySums)
		}
		h.r.Render(r, w, comp)
	}
}

func (h TreasureChestImpl) handleUpdateTreasureChest() http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		user := middleware.GetUser(r)
		if user == nil {
			utils.DoRedirect(w, r, "/auth/signin")
			return
		}

		var (
			treasureChest *types.TreasureChest
			err           error
		)
		id := r.PathValue("id")
		parentId := r.FormValue("parent-id")
		name := r.FormValue("name")
		if id == "new" {
			treasureChest, err = h.s.Add(user, parentId, name)
			if err != nil {
				handleError(w, r, err)
				return
			}
		} else {
			treasureChest, err = h.s.Update(user, id, parentId, name)
			if err != nil {
				handleError(w, r, err)
				return
			}
		}

		transactionsRecurring, err := h.transactionRecurring.GetAllByTreasureChest(user, treasureChest.Id.String())
		if err != nil {
			handleError(w, r, err)
			return
		}

		treasureChests := make([]*types.TreasureChest, 1)
		treasureChests[0] = treasureChest
		monthlySums := h.calculateMonthlySums(treasureChests, transactionsRecurring)
		comp := t.TreasureChestItem(treasureChest, monthlySums)
		h.r.Render(r, w, comp)
	}
}

func (h TreasureChestImpl) handleDeleteTreasureChest() http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		user := middleware.GetUser(r)
		if user == nil {
			utils.DoRedirect(w, r, "/auth/signin")
			return
		}

		id := r.PathValue("id")

		err := h.s.Delete(user, id)
		if err != nil {
			handleError(w, r, err)
			return
		}
	}
}

func (h TreasureChestImpl) calculateMonthlySums(
	treasureChests []*types.TreasureChest,
	transactionsRecurring []*types.TransactionRecurring,
) map[uuid.UUID]int64 {
	monthlySums := make(map[uuid.UUID]int64)
	for _, tc := range treasureChests {
		monthlySums[tc.Id] = 0
	}
	for _, t := range transactionsRecurring {
		if t.TreasureChestId != nil && t.Value > 0 && t.IntervalMonths > 0 {
			monthlySums[*t.TreasureChestId] += t.Value / t.IntervalMonths
		}
	}
	return monthlySums
}