package http

import (
	"net/http"
	"strconv"
	"strings"
	"time"
	"unicode/utf8"

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

type TarifKerjasamaPaginationResponse struct {
	CurrentPage  int                                `json:"current_page"`
	Data         []repository.TarifKerjasamaSummary `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"`
}

type TarifKerjasamaResponse struct {
	Success bool   `json:"success"`
	Status  string `json:"status"`
	Message string `json:"message"`
	Data    any    `json:"data"`
}

func (h Handler) ListTarifKerjasama(w http.ResponseWriter, r *http.Request) {
	params, message := parseTarifKerjasamaListParams(r)
	if message != "" {
		writeTarifKerjasamaValidationError(w, message)
		return
	}

	page, err := h.tarifRepository(r.Context()).ListTarifKerjasama(r.Context(), params)
	if err != nil {
		writeTarifKerjasamaInternalError(w)
		return
	}

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

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

func (h Handler) GetTarifKerjasama(w http.ResponseWriter, r *http.Request) {
	id, params, message := parseTarifKerjasamaDetailParams(r)
	if message != "" {
		writeTarifKerjasamaValidationError(w, message)
		return
	}

	detail, err := h.tarifRepository(r.Context()).GetTarifKerjasama(r.Context(), id, params)
	if err != nil {
		writeTarifKerjasamaInternalError(w)
		return
	}
	if detail == nil {
		WriteJSON(w, http.StatusNotFound, TarifKerjasamaResponse{
			Success: false, Status: "tarif_kerjasama_not_found",
			Message: "Master tarif kerja sama tidak ditemukan", Data: nil,
		})
		return
	}

	WriteJSON(w, http.StatusOK, TarifKerjasamaResponse{
		Success: true, Status: "tarif_kerjasama_found",
		Message: "Data tarif kerja sama berhasil diambil", Data: detail,
	})
}

func parseTarifKerjasamaListParams(r *http.Request) (repository.TarifKerjasamaListParams, string) {
	query := r.URL.Query()
	params := repository.TarifKerjasamaListParams{
		Search:       strings.TrimSpace(query.Get("search")),
		PerusahaanID: strings.TrimSpace(query.Get("perusahaan_id")),
		Page:         1, PerPage: 15,
	}
	if utf8.RuneCountInString(params.Search) > 255 {
		return params, "The search may not be greater than 255 characters."
	}
	if utf8.RuneCountInString(params.PerusahaanID) > 50 {
		return params, "The perusahaan id may not be greater than 50 characters."
	}
	if raw, exists := firstQueryValue(r, "tarif_id"); exists && raw != "" {
		value, err := positiveInt64(raw)
		if err != nil {
			return params, "The tarif id must be a positive integer."
		}
		params.TarifID = &value
	}
	if raw, exists := firstQueryValue(r, "page"); exists && raw != "" {
		value, err := strconv.Atoi(raw)
		if err != nil || value < 1 {
			return params, "The page must be at least 1."
		}
		params.Page = value
	}
	if raw, exists := firstQueryValue(r, "per_page"); exists && raw != "" {
		value, err := strconv.Atoi(raw)
		if err != nil || value < 1 || value > 100 {
			return params, "The per page must be between 1 and 100."
		}
		params.PerPage = value
	}

	return params, ""
}

func parseTarifKerjasamaDetailParams(r *http.Request) (int64, repository.TarifKerjasamaDetailParams, string) {
	params := repository.TarifKerjasamaDetailParams{Active: "N"}
	id, err := positiveInt64(strings.TrimSpace(r.PathValue("id")))
	if err != nil {
		return 0, params, "The id must be a positive integer."
	}
	if raw, exists := firstQueryValue(r, "group_tarif_id"); exists && raw != "" {
		value, err := positiveInt64(raw)
		if err != nil {
			return 0, params, "The group tarif id must be a positive integer."
		}
		params.GroupTarifID = &value
	}
	if raw, exists := firstQueryValue(r, "active"); exists && raw != "" {
		if raw != "N" && raw != "Y" {
			return 0, params, "The selected active is invalid."
		}
		params.Active = raw
	}
	params.EffectiveDate = strings.TrimSpace(r.URL.Query().Get("effective_date"))
	if params.EffectiveDate != "" {
		if _, err := time.Parse("2006-01-02", params.EffectiveDate); err != nil {
			return 0, params, "The effective date does not match the format Y-m-d."
		}
	}

	return id, params, ""
}

func positiveInt64(raw string) (int64, error) {
	value, err := strconv.ParseInt(strings.TrimSpace(raw), 10, 64)
	if err != nil || value < 1 {
		return 0, strconv.ErrSyntax
	}
	return value, nil
}

func writeTarifKerjasamaValidationError(w http.ResponseWriter, message string) {
	WriteJSON(w, http.StatusUnprocessableEntity, TarifKerjasamaResponse{
		Success: false, Status: "validation_error", Message: message, Data: nil,
	})
}

func writeTarifKerjasamaInternalError(w http.ResponseWriter) {
	WriteJSON(w, http.StatusInternalServerError, Response{
		Success: false, Message: "internal server error", Data: nil,
	})
}