package http

import (
	"errors"
	"net/http"
	"net/url"
	"strconv"
	"strings"

	"primaya-api/cpone-middleware/internal/repository"
)

const periodeTarifLayananPerPage = 20

type PeriodeTarifLayananPaginationResponse struct {
	CurrentPage  int                              `json:"current_page"`
	Data         []repository.PeriodeTarifLayanan `json:"data"`
	FirstPageURL string                           `json:"first_page_url"`
	From         *int                             `json:"from"`
	LastPage     int                              `json:"last_page"`
	LastPageURL  string                           `json:"last_page_url"`
	Links        map[string]any                   `json:"links"`
	NextPageURL  *string                          `json:"next_page_url"`
	Total        int                              `json:"total"`
	PerPage      int                              `json:"per_page"`
}

func (h Handler) ListPeriodeTarifLayanan(w http.ResponseWriter, r *http.Request) {
	rawID := strings.TrimSpace(r.PathValue("periodeTarifID"))
	if rawID == "" {
		rawID = strings.TrimSpace(r.PathValue("PeriodeTarifID"))
	}
	periodeTarifID, err := strconv.ParseInt(rawID, 10, 64)
	if err != nil || periodeTarifID < 1 {
		WriteJSON(w, http.StatusUnprocessableEntity, Response{
			Success: false,
			Message: "PeriodeTarifID harus berupa angka positif",
			Data:    nil,
		})
		return
	}

	pageNumber := periodeTarifLayananPageNumber(r)
	search := strings.TrimSpace(r.URL.Query().Get("search"))
	page, err := h.periodeTarifDetailRepository(r.Context()).ListPeriodeTarifLayanan(r.Context(), repository.PeriodeTarifLayananListParams{
		PeriodeTarifID: periodeTarifID,
		Page:           pageNumber,
		PerPage:        periodeTarifLayananPerPage,
		Search:         search,
	})
	if errors.Is(err, repository.ErrTarifTableNotFound) {
		WriteJSON(w, http.StatusNotFound, Response{
			Success: false,
			Message: "Tabel tarif tidak ditemukan: harga_layanan_" + strconv.FormatInt(periodeTarifID, 10),
			Data:    nil,
		})
		return
	}
	if err != nil {
		WriteJSON(w, http.StatusInternalServerError, Response{
			Success: false,
			Message: "internal server error",
			Data:    nil,
		})
		return
	}

	if page.Items == nil {
		page.Items = []repository.PeriodeTarifLayanan{}
	}

	lastPage := (page.Total + periodeTarifLayananPerPage - 1) / periodeTarifLayananPerPage
	if lastPage < 1 {
		lastPage = 1
	}
	var from *int
	if len(page.Items) > 0 {
		value := (pageNumber-1)*periodeTarifLayananPerPage + 1
		from = &value
	}
	var nextPageURL *string
	if pageNumber < lastPage {
		value := periodeTarifLayananPageURL(r, pageNumber+1)
		nextPageURL = &value
	}

	WriteJSON(w, http.StatusOK, PeriodeTarifLayananPaginationResponse{
		CurrentPage: pageNumber, Data: page.Items, FirstPageURL: "", From: from,
		LastPage: lastPage, LastPageURL: "", Links: map[string]any{},
		NextPageURL: nextPageURL, Total: page.Total, PerPage: periodeTarifLayananPerPage,
	})
}

func periodeTarifLayananPageNumber(r *http.Request) int {
	page, err := strconv.Atoi(r.URL.Query().Get("page"))
	if err != nil || page < 1 {
		return 1
	}
	return page
}

func periodeTarifLayananPageURL(r *http.Request, page int) string {
	scheme := "http"
	if r.TLS != nil {
		scheme = "https"
	}
	if forwarded := r.Header.Get("X-Forwarded-Proto"); forwarded != "" {
		scheme = strings.TrimSpace(strings.Split(forwarded, ",")[0])
	}
	host := r.Host
	if host == "" {
		host = "localhost"
	}
	query := r.URL.Query()
	query.Set("page", strconv.Itoa(page))
	query.Set("per_page", strconv.Itoa(periodeTarifLayananPerPage))
	return (&url.URL{Scheme: scheme, Host: host, Path: r.URL.Path, RawQuery: query.Encode()}).String()
}