import {
  AllCommunityModule,
  ModuleRegistry,
  createGrid,
} from "ag-grid-community";
import "ag-grid-community/styles/ag-grid.css";
import "ag-grid-community/styles/ag-theme-quartz.css";

ModuleRegistry.registerModules([AllCommunityModule]);

const DEFAULT_SELECTOR = "[data-portfolio-list-panel]";
const DEFAULT_PAGE_SIZE = 5;

function toDate(value) {
  if (!value) {
    return null;
  }

  const date = new Date(value);
  return Number.isNaN(date.getTime()) ? null : date;
}

function formatDate(value) {
  const date = toDate(value);
  if (!date) {
    return "";
  }

  return new Intl.DateTimeFormat("ko-KR", {
    year: "numeric",
    month: "2-digit",
    day: "2-digit",
  }).format(date);
}

function formatRelativeDate(value) {
  const date = toDate(value);
  if (!date) {
    return "";
  }

  const diffMs = Date.now() - date.getTime();
  if (diffMs < 0) {
    return formatDate(value);
  }

  const diffMinutes = Math.floor(diffMs / 60000);
  if (diffMinutes < 1) {
    return "방금 전";
  }

  if (diffMinutes < 60) {
    return `${diffMinutes}분 전`;
  }

  const diffHours = Math.floor(diffMinutes / 60);
  if (diffHours < 24) {
    return `${diffHours}시간 전`;
  }

  return formatDate(value);
}

function getPostUrl(portfolioIdntfNo) {
  return `/portfolio/${encodeURIComponent(portfolioIdntfNo)}`;
}

function createTitleCell(params) {
  const link = document.createElement("a");
  link.className = "portfolio-post-title-link";
  link.href = getPostUrl(params.data.portfolioIdntfNo);
  link.textContent = params.value || "";
  link.title = params.value || "";
  return link;
}

function createPageButton(label, options = {}) {
  const button = document.createElement("button");
  button.type = "button";
  button.className = "portfolio-post-page-button";
  button.textContent = label;

  if (options.active) {
    button.classList.add("is-active");
    button.setAttribute("aria-current", "page");
  }

  if (options.disabled) {
    button.disabled = true;
  }

  if (typeof options.onClick === "function") {
    button.addEventListener("click", options.onClick);
  }

  return button;
}

function renderPagination(gridApi, paginationElement) {
  if (!gridApi || !paginationElement) {
    return;
  }

  const totalPages = gridApi.paginationGetTotalPages();
  const currentPage = gridApi.paginationGetCurrentPage();
  paginationElement.replaceChildren();

  if (totalPages <= 0) {
    return;
  }

  const maxVisiblePages = 10;
  const currentPageGroup = Math.floor(currentPage / maxVisiblePages);
  const startPage = currentPageGroup * maxVisiblePages;
  const endPage = Math.min(startPage + maxVisiblePages, totalPages);

  if (startPage > 0) {
    paginationElement.appendChild(
      createPageButton("이전", {
        onClick: () => gridApi.paginationGoToPage(startPage - 1),
      }),
    );
  }

  for (let page = startPage; page < endPage; page += 1) {
    paginationElement.appendChild(
      createPageButton(String(page + 1), {
        active: page === currentPage,
        onClick: () => gridApi.paginationGoToPage(page),
      }),
    );
  }

  if (endPage < totalPages) {
    paginationElement.appendChild(
      createPageButton("다음 >", {
        onClick: () => gridApi.paginationGoToPage(endPage),
      }),
    );
  }
}

function createGridOptions(rows, currentId, paginationElement) {
  return {
    rowData: rows,
    columnDefs: [
      {
        field: "title",
        headerName: "글 제목",
        flex: 1,
        minWidth: 260,
        cellRenderer: createTitleCell,
      },
      {
        field: "viewCount",
        headerName: "조회수",
        width: 96,
        type: "numericColumn",
        headerClass: "portfolio-post-number-header",
        cellClass: "portfolio-post-number-cell",
      },
      {
        field: "registeredAt",
        headerName: "작성일",
        width: 132,
        valueFormatter: (params) => formatRelativeDate(params.value),
        headerClass: "portfolio-post-date-header",
        cellClass: "portfolio-post-date-cell",
      },
    ],
    defaultColDef: {
      sortable: true,
      resizable: false,
      suppressMovable: true,
    },
    domLayout: "autoHeight",
    headerHeight: 34,
    rowHeight: 40,
    pagination: true,
    paginationPageSize: DEFAULT_PAGE_SIZE,
    suppressPaginationPanel: true,
    suppressCellFocus: true,
    suppressDragLeaveHidesColumns: true,
    suppressHorizontalScroll: true,
    getRowId: (params) => params.data.portfolioIdntfNo,
    getRowClass: (params) =>
      params.data.portfolioIdntfNo === currentId ? "ag-row-current-post" : "",
    onGridReady: (params) => renderPagination(params.api, paginationElement),
    onPaginationChanged: (event) => renderPagination(event.api, paginationElement),
    localeText: {
      page: "페이지",
      more: "더 보기",
      to: "-",
      of: "/",
      next: "다음",
      last: "마지막",
      first: "처음",
      previous: "이전",
      loadingOoo: "불러오는 중...",
      noRowsToShow: "등록된 글이 없습니다.",
      pageSizeSelectorLabel: "줄 보기",
    },
  };
}

async function fetchPortfolioItems(listUrl) {
  const response = await fetch(listUrl, {
    headers: {
      Accept: "application/json",
    },
    credentials: "same-origin",
  });

  if (!response.ok) {
    throw new Error("포트폴리오 목록을 불러오지 못했습니다.");
  }

  const rows = await response.json();
  return Array.isArray(rows) ? rows : [];
}

function initPortfolioListPanel(selector = DEFAULT_SELECTOR) {
  const panel = document.querySelector(selector);
  if (!panel) {
    return null;
  }

  const toggleButton = panel.querySelector("[data-portfolio-list-toggle]");
  const body = panel.querySelector("[data-portfolio-list-body]");
  const gridElement = panel.querySelector("[data-portfolio-list-grid]");
  const paginationElement = panel.querySelector("[data-portfolio-pagination]");
  const pageSizeSelect = panel.querySelector("[data-portfolio-page-size]");
  const countElement = panel.querySelector(".portfolio-post-list-summary span");
  const listUrl = panel.dataset.listUrl;
  const currentId = panel.dataset.currentId || "";
  const initialOpen = panel.dataset.initialOpen === "true";

  if (!toggleButton || !body || !gridElement || !paginationElement || !listUrl) {
    return null;
  }

  let isOpen = false;
  let rowsPromise = null;
  let gridApi = null;

  const loadRows = () => {
    rowsPromise ||= fetchPortfolioItems(listUrl);
    return rowsPromise;
  };

  const renderRows = async () => {
    const rows = await loadRows();

    if (countElement) {
      countElement.textContent = `${rows.length}개의 글`;
    }

    if (!gridApi) {
      gridApi = createGrid(
        gridElement,
        createGridOptions(rows, currentId, paginationElement),
      );
      renderPagination(gridApi, paginationElement);
      return;
    }

    gridApi.setGridOption("rowData", rows);
    renderPagination(gridApi, paginationElement);
  };

  const setOpen = async (nextOpen) => {
    isOpen = nextOpen;
    toggleButton.textContent = isOpen ? "목록닫기" : "목록열기";
    toggleButton.setAttribute("aria-expanded", String(isOpen));
    body.hidden = !isOpen;

    if (!isOpen) {
      return;
    }

    toggleButton.disabled = true;
    try {
      await renderRows();
    } catch (error) {
      window.alert(error.message || "포트폴리오 목록을 불러오지 못했습니다.");
      setOpen(false);
    } finally {
      toggleButton.disabled = false;
    }
  };

  toggleButton.addEventListener("click", () => {
    void setOpen(!isOpen);
  });

  pageSizeSelect?.addEventListener("change", () => {
    if (!gridApi) {
      return;
    }

    gridApi.setGridOption(
      "paginationPageSize",
      Number.parseInt(pageSizeSelect.value, 10) || DEFAULT_PAGE_SIZE,
    );
    gridApi.paginationGoToPage(0);
    renderPagination(gridApi, paginationElement);
  });

  void setOpen(initialOpen);

  return {
    open: () => setOpen(true),
    close: () => setOpen(false),
    reload: async () => {
      rowsPromise = null;
      await renderRows();
    },
  };
}

document.addEventListener("DOMContentLoaded", () => {
  initPortfolioListPanel();
});

export { initPortfolioListPanel };