/* =============================================================================
 * B07_wf4_DesignDetail_UI_Page.ts
 * 로그인 후 07: 4차 워크플로우 (상세 설계) — 독립형 2D CAD 임베드
 *
 * B07_wf4_DesignDetail/openwebcad를 프로젝트 소유 B07 CAD 앱으로 빌드하여
 * /b07-cad 경로로 서빙한다. 업무 도면은 추후 same-origin postMessage로
 * JSON만 전달하며 DXF/DWG 파싱은 이 브라우저 앱에서 수행하지 않는다.
 *
 * 레이아웃 (사용자 지시): 사이드 패널 빈 상태 유지 + 상세 영역 CAD 화면.
 * 제약 준수 (frontend.md §2 3단 레이아웃): createWorkflowLayout 재사용.
 * ========================================================================== */

import "./B07_wf4_DesignDetail_UI_Style.css";
import { ui_locales, currentLanguageIndex } from "@ui/ui_template_locale";
import {
  createButton,
  hideLoadingOverlay,
  showLoadingOverlay,
  showToast,
} from "@ui/ui_template_elements";
import { createWorkflowLayout } from "@ui/ui_template_workflow_layout";
import { CURRENT_PROJECT_ID_KEY } from "@config/config_frontend";
import { workflowSteps } from "../A00_Common/b_page_scaffold";
import {
  fetchWorkflowState,
  goToWorkflowStage,
  WORKFLOW_STEP_ROUTES,
  type WorkflowState,
} from "../A00_Common/b_workflow_nav";
import {
  confirmDesignDrawing,
  fetchDesignDrawing,
  fetchDesignDrawingList,
  invalidateDesignDrawing,
  type CadDrawing,
  type DesignDrawingItem,
} from "./B07_wf4_DesignDetail_Api_Fetch";

/** B07 독립형 CAD 정적 경로 (main.py 마운트, dev는 vite proxy 위임) */
const B07_CAD_APP_URL = "/b07-cad/index.html";

/** locale 헬퍼 */
function L(key: keyof typeof ui_locales): string {
  return ui_locales[key][currentLanguageIndex];
}

const CAD_LOAD_MESSAGE = "aislo:b07:load-drawing";
const CAD_READY_MESSAGE = "aislo:b07:drawing-ready";
const CAD_LOADED_MESSAGE = "aislo:b07:drawing-loaded";
const CAD_ERROR_MESSAGE = "aislo:b07:drawing-error";
const CAD_CHANGED_MESSAGE = "aislo:b07:drawing-changed";
const CAD_SAVE_REQUEST_MESSAGE = "aislo:b07:save-request";
const CAD_SAVE_RESPONSE_MESSAGE = "aislo:b07:save-response";

/** B06 확정 산출물 기반 도면 목록 패널. */
function buildDrawingSidePanel(
  drawings: DesignDrawingItem[],
  onSelect: (drawing: DesignDrawingItem, button: HTMLButtonElement) => Promise<void>,
  errorMessage?: string,
): HTMLDivElement {
  const panel = document.createElement("div");
  panel.className = "b07-drawing-list";
  const heading = document.createElement("div");
  heading.className = "b07-drawing-list__heading";
  const title = document.createElement("strong");
  title.textContent = "설계 도면";
  const count = document.createElement("span");
  count.textContent = `${drawings.length}건`;
  heading.append(title, count);
  panel.append(heading);

  if (errorMessage || drawings.length === 0) {
    const empty = document.createElement("p");
    empty.className = "b07-drawing-list__empty";
    empty.textContent = errorMessage ?? "확정된 종·횡단 도면이 없습니다.";
    panel.append(empty);
    return panel;
  }

  const groups: [string, DesignDrawingItem[]][] = [
    ["종단도", drawings.filter((item) => item.kind === "longitudinal")],
    ["횡단도", drawings.filter((item) => item.kind === "cross")],
  ];
  for (const [label, items] of groups) {
    if (!items.length) continue;
    const section = document.createElement("section");
    section.className = "b07-drawing-group";
    const sectionTitle = document.createElement("h3");
    sectionTitle.textContent = `${label} ${items.length}`;
    section.append(sectionTitle);
    for (const drawing of items) {
      const button = document.createElement("button");
      button.type = "button";
      button.className = "b07-drawing-button";
      button.dataset.drawingId = drawing.id;
      button.dataset.confirmed = String(drawing.confirmed);
      const name = document.createElement("span");
      name.textContent = drawing.label;
      const kind = document.createElement("small");
      kind.textContent = drawing.confirmed
        ? "확정"
        : drawing.kind === "longitudinal"
          ? "PROFILE"
          : "SECTION";
      button.append(name, kind);
      button.addEventListener("click", () => void onSelect(drawing, button));
      section.append(button);
    }
    panel.append(section);
  }
  return panel;
}

/* -----------------------------------------------------------------------------
 * 페이지 진입점
 * -------------------------------------------------------------------------- */
export async function renderB07DesignDetail(root: HTMLElement): Promise<void> {
  const projectId = localStorage.getItem(CURRENT_PROJECT_ID_KEY);
  let workflowState: WorkflowState | undefined;
  let drawings: DesignDrawingItem[] = [];
  let drawingError: string | undefined;
  if (projectId) {
    const [workflowResult, drawingResult] = await Promise.allSettled([
      fetchWorkflowState(projectId),
      fetchDesignDrawingList(projectId),
    ]);
    if (workflowResult.status === "fulfilled") workflowState = workflowResult.value;
    if (drawingResult.status === "fulfilled") drawings = drawingResult.value.drawings;
    else
      drawingError =
        drawingResult.reason instanceof Error
          ? drawingResult.reason.message
          : "도면 목록을 불러오지 못했습니다.";
  }

  const cadHost = document.createElement("div");
  cadHost.className = "b07-cad-host";
  const frame = document.createElement("iframe");
  frame.className = "b07-cad-frame";
  frame.src = B07_CAD_APP_URL;
  frame.title = L("B07_Design_Title");
  const license = document.createElement("a");
  license.className = "b07-cad-license";
  license.href = "/b07-cad/THIRD_PARTY_LICENSES.txt";
  license.target = "_blank";
  license.rel = "noreferrer";
  license.textContent = "Drawing engine based on OpenWebCAD · MIT License";
  cadHost.append(frame, license);

  let cadReady = false;
  let pendingDrawing: CadDrawing | undefined;
  let currentDrawing: DesignDrawingItem | undefined;
  let currentButton: HTMLButtonElement | undefined;
  let currentConfirmed = false;
  let allDrawingsConfirmed = drawings.length > 0 && drawings.every((item) => item.confirmed);
  let resolveSave: ((drawing: CadDrawing) => void) | undefined;
  const confirmButton = createButton({
    label: "현재 도면 확정",
    variant: "filled",
    onClick: () => void confirmCurrentDrawing(),
  });
  confirmButton.disabled = true;
  const sendDrawing = (drawing: CadDrawing) => {
    pendingDrawing = drawing;
    if (!cadReady) return;
    frame.contentWindow?.postMessage({ type: CAD_LOAD_MESSAGE, drawing }, window.location.origin);
    pendingDrawing = undefined;
  };
  const selectDrawing = async (drawing: DesignDrawingItem, button: HTMLButtonElement) => {
    if (!projectId) return;
    const buttons = button
      .closest(".b07-drawing-list")
      ?.querySelectorAll<HTMLButtonElement>(".b07-drawing-button");
    buttons?.forEach((item) => {
      item.disabled = true;
      item.dataset.active = String(item === button);
    });
    button.dataset.loading = "true";
    cadHost.dataset.loading = "true";
    try {
      const response = await fetchDesignDrawing(projectId, drawing.id);
      currentDrawing = drawing;
      currentButton = button;
      currentConfirmed = response.confirmed;
      confirmButton.disabled = response.confirmed;
      sendDrawing(response.drawing);
    } catch (error) {
      cadHost.dataset.loading = "false";
      cadHost.dataset.error =
        error instanceof Error ? error.message : "CAD 도면을 불러오지 못했습니다.";
    } finally {
      button.dataset.loading = "false";
      buttons?.forEach((item) => {
        item.disabled = false;
      });
    }
  };

  const requestCadDrawing = (): Promise<CadDrawing> =>
    new Promise((resolve, reject) => {
      resolveSave = resolve;
      frame.contentWindow?.postMessage({ type: CAD_SAVE_REQUEST_MESSAGE }, window.location.origin);
      window.setTimeout(() => {
        if (!resolveSave) return;
        resolveSave = undefined;
        reject(new Error("CAD 저장 응답 시간이 초과되었습니다."));
      }, 5000);
    });

  async function confirmCurrentDrawing(): Promise<void> {
    if (!projectId || !currentDrawing) return;
    showLoadingOverlay();
    try {
      const drawing = await requestCadDrawing();
      const result = await confirmDesignDrawing(projectId, currentDrawing.id, drawing);
      currentConfirmed = true;
      currentDrawing.confirmed = true;
      confirmButton.disabled = true;
      if (currentButton) {
        currentButton.dataset.confirmed = "true";
        const status = currentButton.querySelector("small");
        if (status) status.textContent = "확정";
      }
      showToast("현재 도면을 확정하고 저장했습니다.", "success");
      if (result.all_confirmed) {
        allDrawingsConfirmed = true;
        goToWorkflowStage(projectId, WORKFLOW_STEP_ROUTES[5]);
      }
    } catch (error) {
      showToast(
        error instanceof Error ? error.message : "현재 도면을 확정하지 못했습니다.",
        "error",
      );
    } finally {
      hideLoadingOverlay();
    }
  }

  const invalidateCurrentDrawing = async () => {
    if (!projectId || !currentDrawing) return;
    const wasConfirmed = currentConfirmed;
    currentConfirmed = false;
    allDrawingsConfirmed = false;
    currentDrawing.confirmed = false;
    confirmButton.disabled = false;
    if (currentButton) {
      currentButton.dataset.confirmed = "false";
      const status = currentButton.querySelector("small");
      if (status)
        status.textContent = currentDrawing.kind === "longitudinal" ? "PROFILE" : "SECTION";
    }
    if (wasConfirmed) {
      try {
        await invalidateDesignDrawing(projectId, currentDrawing.id);
      } catch (error) {
        showToast(
          error instanceof Error ? error.message : "도면 확정 상태를 되돌리지 못했습니다.",
          "error",
        );
      }
    }
  };

  window.addEventListener("message", (event: MessageEvent<unknown>) => {
    if (event.origin !== window.location.origin || event.source !== frame.contentWindow) return;
    const message = event.data as {
      type?: string;
      detail?: string;
      drawing?: CadDrawing;
    };
    if (message.type === CAD_READY_MESSAGE) {
      cadReady = true;
      if (pendingDrawing) sendDrawing(pendingDrawing);
    } else if (message.type === CAD_LOADED_MESSAGE) {
      cadHost.dataset.loading = "false";
    } else if (message.type === CAD_ERROR_MESSAGE) {
      cadHost.dataset.error = message.detail ?? "CAD 도면을 표시하지 못했습니다.";
    } else if (message.type === CAD_CHANGED_MESSAGE) {
      void invalidateCurrentDrawing();
    } else if (message.type === CAD_SAVE_RESPONSE_MESSAGE && message.drawing && resolveSave) {
      const resolve = resolveSave;
      resolveSave = undefined;
      resolve(message.drawing);
    }
  });

  const drawingPanel = buildDrawingSidePanel(drawings, selectDrawing, drawingError);
  const confirmActions = document.createElement("div");
  confirmActions.className = "b07-drawing-actions";
  confirmActions.append(confirmButton);
  drawingPanel.append(confirmActions);

  const layout = createWorkflowLayout({
    title: L("B07_Design_Title"),
    steps: workflowSteps(),
    activeStep: 4,
    leftPanel: drawingPanel,
    mainContent: cadHost,
    stages: workflowState?.stages,
    currentStage: workflowState?.current_stage,
    routes: WORKFLOW_STEP_ROUTES,
    onStepClick: (stepIndex) => {
      if (!projectId) return;
      if (stepIndex > 4 && !allDrawingsConfirmed) {
        showToast("모든 설계 도면을 확정한 뒤 다음 단계로 이동할 수 있습니다.", "warning");
        return;
      }
      goToWorkflowStage(projectId, WORKFLOW_STEP_ROUTES[stepIndex]);
    },
  });
  layout.root.classList.add("b07-design-layout");
  root.replaceChildren(layout.root);
}