/**
 * upload.js — Загрузка и импорт фотографий через drag-and-drop или file picker
 */

import { apiFetch } from "./api.js";
import { getState, setBusy } from "./state.js";
import { setJobStatus, isHeicFile, ACCEPTED_TYPES, MAX_FILE_SIZE } from "./ui.js";
import { refreshHistory } from "./history-tree.js";

export async function importPhoto(file) {
  const form = new FormData();
  form.append("photo", file, file.name);

  const data = await apiFetch("/api/history/import", {
    method: "POST",
    body: form,
    cache: "no-store",
  });

  return data.version;
}

export async function handleFiles(fileList) {
  const files = Array.from(fileList || []).filter((file) => {
    const fileType = String(file.type || "").toLowerCase();

    if (!ACCEPTED_TYPES.has(fileType) && !isHeicFile(file)) {
      setJobStatus("error", "Поддерживаются только фотографии JPEG, PNG, WebP или HEIC.");
      return false;
    }

    if (file.size > MAX_FILE_SIZE) {
      setJobStatus("error", "Файл слишком большой. Максимальный размер — 25 МБ.");
      return false;
    }

    return true;
  });

  if (files.length === 0) return;

  setBusy(true);

  for (let i = 0; i < files.length; i++) {
    const file = files[i];

    setJobStatus(
      "progress",
      files.length > 1
        ? `Загрузка ${i + 1} из ${files.length}…`
        : "Загружаем фотографию в историю…"
    );

    try {
      await importPhoto(file);
    } catch (error) {
      setBusy(false);
      setJobStatus(
        "error",
        error instanceof Error ? error.message : "Не удалось загрузить фотографию."
      );
      return;
    }
  }

  await refreshHistory(true);
  setJobStatus("idle", "");
  setBusy(false);
}

export function initUpload() {
  const dropZone = document.querySelector("#drop-zone");
  const photoInput = document.querySelector("#photo-input");

  if (dropZone && photoInput) {
    dropZone.addEventListener("click", () => {
      const state = getState();
      if (!state.isBusy) {
        photoInput.click();
      }
    });

    dropZone.addEventListener("keydown", (event) => {
      if (event.key === "Enter" || event.key === " ") {
        event.preventDefault();
        const state = getState();
        if (!state.isBusy) {
          photoInput.click();
        }
      }
    });

    photoInput.addEventListener("change", (event) => {
      handleFiles(event.target.files);
      photoInput.value = "";
    });

    const preventDefaults = (e) => {
      e.preventDefault();
      e.stopPropagation();
    };

    ["dragenter", "dragover", "dragleave", "drop"].forEach((evt) => {
      dropZone.addEventListener(evt, preventDefaults, false);
      document.body.addEventListener(evt, preventDefaults, false);
    });

    ["dragenter", "dragover"].forEach((evt) => {
      dropZone.addEventListener(evt, () => dropZone.classList.add("dragover"), false);
    });

    ["dragleave", "drop"].forEach((evt) => {
      dropZone.addEventListener(evt, () => dropZone.classList.remove("dragover"), false);
    });

    dropZone.addEventListener("drop", (event) => {
      const state = getState();
      if (!state.isBusy && event.dataTransfer?.files) {
        handleFiles(event.dataTransfer.files);
      }
    });
  }
}