package backend

import (
	"log/slog"
	"maps"
	"net/http"
	"slices"
	"strconv"
	"time"

	"github.com/go-chi/chi/v5"
)

const maxLogsPerPage = 5

var sortedLogs []*logData

type homeData struct {
	*data
	Logs        []*logData
	PagesNumber int
	CurrentPage int
}

func (h *homeData) SetData(d *data) {
	h.data = d
}

func HandleHome(r *chi.Mux) {
	r.Get("/", func(w http.ResponseWriter, r *http.Request) {
		rawPage := r.URL.Query().Get("page")
		page := 1
		if rawPage != "" {
			var err error
			page, err = strconv.Atoi(rawPage)
			if err != nil || page < 1 {
				slog.Warn("invalid page number", "rawPage", rawPage)
				w.WriteHeader(http.StatusBadRequest)
				return
			}
		}
		d := new(homeData)
		d.data = new(data)
		if sortedLogs == nil {
			sortLogs()
		}
		d.CurrentPage = page
		d.PagesNumber = len(sortedLogs)/maxLogsPerPage + 1
		if d.PagesNumber < page {
			http.NotFoundHandler().ServeHTTP(w, r)
			return
		}
		d.Logs = sortedLogs[(page-1)*maxLogsPerPage : min(page*maxLogsPerPage, len(sortedLogs))]
		d.handleGeneric(w, r, "home", d)
	})
}

func sortLogs() {
	sortedLogs = slices.SortedFunc(maps.Values(logs), func(l *logData, l2 *logData) int {
		lt := l.pubDate.AsTime(time.UTC)
		l2t := l2.pubDate.AsTime(time.UTC)
		// we want it reversed
		if lt.Before(l2t) {
			return 1
		} else if lt.After(l2t) {
			return -1
		}
		return 0
	})
}