/* =============================================================================
 * B04_wf1_Surface_UI_Page.ts
 * 로그인 후 04: 1차 워크플로우 (지표면 모델 분석)
 *
 * 3단 레이아웃 (frontend.md §2):
 *   상단: 페이지 타이틀 + 진행 단계 스텝바 (createWorkflowShell)
 *   좌측: 입력 파일 ID + 지면 필터/지표면 표현 선택 + 실행 옵션 폼
 *   우측: 생성된 지표면 모델 목록 그리드
 *
 * 이벤트 핸들러 명명 (frontend.md §4): onB04_Surface_[기능]_[액션]
 * 텍스트는 ui_template_locale에 선(先) 등록 후 참조 (frontend.md §3).
 * ========================================================================== */

import { CURRENT_PROJECT_ID_KEY } from "@config/config_frontend";
import { currentLanguageIndex, ui_locales } from "@ui/ui_template_locale";
import {
  createButton,
  createInputField,
  createTag,
  createWorkflowShell,
  hideLoadingOverlay,
  showLoadingOverlay,
  showToast,
} from "@ui/ui_template_elements";
import { workflowSteps } from "../A00_Common/b_page_scaffold";
import {
  analyzeSurface,
  listSurfaceModels,
  type SurfaceModelSummary,
} from "./B04_wf1_Surface_Api_Fetch";
import "./B04_wf1_Surface_UI_Style.css";

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

/** 선택 가능한 지면 필터 (config_system.SURFACE_MODEL_SOURCE_FILTERS + ransac) */
const SOURCE_FILTERS = ["grid_min_z", "csf", "pmf", "ransac"] as const;
/** 선택 가능한 지표면 표현 (config_system.SURFACE_MODEL_PRECOMPUTE) */
const MODEL_METHODS = ["tin", "dtm", "nurbs", "implicit", "meshfree"] as const;

/** 체크박스 그룹 하나 생성 (라벨 + 항목들). 선택 값 Set을 반환. */
function buildCheckboxGroup(
  legend: string,
  values: readonly string[],
  defaults: readonly string[],
): { root: HTMLElement; selected: Set<string> } {
  const selected = new Set<string>(defaults);
  const root = document.createElement("fieldset");
  root.className = "b04-surface__group";
  const legendEl = document.createElement("legend");
  legendEl.className = "b04-surface__group-legend";
  legendEl.textContent = legend;
  root.append(legendEl);

  for (const value of values) {
    const item = document.createElement("label");
    item.className = "b04-surface__check";
    const box = document.createElement("input");
    box.type = "checkbox";
    box.value = value;
    box.checked = selected.has(value);
    box.addEventListener("change", () => {
      if (box.checked) selected.add(value);
      else selected.delete(value);
    });
    const text = document.createElement("span");
    text.textContent = value;
    item.append(box, text);
    root.append(item);
  }
  return { root, selected };
}

export function renderB04Surface(root: HTMLElement): void {
  const shell = createWorkflowShell({
    title: L("B04_Surface_Title"),
    steps: workflowSteps(),
    activeStep: 0,
  });

  /* ---- 좌측 입력 패널 ---- */
  const inputFileField = createInputField({
    label: L("B04_Surface_Field_InputId"),
    type: "number",
    min: 1,
    placeholder: L("B04_Surface_Field_InputId_Placeholder"),
  });

  const filterGroup = buildCheckboxGroup(L("B04_Surface_Group_Filters"), SOURCE_FILTERS, [
    "grid_min_z",
    "csf",
    "pmf",
  ]);
  const methodGroup = buildCheckboxGroup(L("B04_Surface_Group_Methods"), MODEL_METHODS, [
    "dtm",
    "tin",
  ]);

  const forceLabel = document.createElement("label");
  forceLabel.className = "b04-surface__check";
  const forceBox = document.createElement("input");
  forceBox.type = "checkbox";
  const forceText = document.createElement("span");
  forceText.textContent = L("B04_Surface_Field_Force");
  forceLabel.append(forceBox, forceText);

  const analyzeButton = createButton({
    label: L("B04_Surface_Btn_Analyze"),
    variant: "filled",
    onClick: () => void onB04_Surface_Analyze_Click(),
  });

  const leftForm = document.createElement("div");
  leftForm.className = "b04-surface__form";
  leftForm.append(
    inputFileField.root,
    filterGroup.root,
    methodGroup.root,
    forceLabel,
    analyzeButton,
  );
  shell.leftPanel.append(leftForm);

  /* ---- 우측 결과 영역 ---- */
  const resultHeader = document.createElement("div");
  resultHeader.className = "b04-surface__result-head";
  const resultTitle = document.createElement("h3");
  resultTitle.textContent = L("B04_Surface_Result_Title");
  const refreshButton = createButton({
    label: L("B04_Surface_Btn_Refresh"),
    variant: "ghost",
    onClick: () => void onB04_Surface_Refresh_Click(),
  });
  resultHeader.append(resultTitle, refreshButton);

  const modelList = document.createElement("div");
  modelList.className = "b04-surface__models";

  const resultArea = document.createElement("div");
  resultArea.className = "b04-surface__result";
  resultArea.append(resultHeader, modelList);
  shell.rightArea.append(resultArea);

  function renderModels(models: readonly SurfaceModelSummary[]): void {
    modelList.replaceChildren();
    if (models.length === 0) {
      const empty = document.createElement("p");
      empty.className = "b04-surface__empty";
      empty.textContent = L("B04_Surface_Result_Empty");
      modelList.append(empty);
      return;
    }
    for (const model of models) {
      const card = document.createElement("div");
      card.className = "b04-surface__model-card";
      const head = document.createElement("div");
      head.className = "b04-surface__model-head";
      const type = document.createElement("strong");
      type.textContent = model.model_type;
      const variant =
        model.status === "CONFIRMED" ? "success" : model.status === "FAILED" ? "danger" : "neutral";
      head.append(type, createTag(model.status, variant));

      const meta = document.createElement("div");
      meta.className = "b04-surface__model-meta";
      const resolution = document.createElement("span");
      resolution.textContent = `${L("B04_Surface_Model_Resolution")}: ${
        model.resolution_m ?? "-"
      }`;
      const path = document.createElement("span");
      path.textContent = `${L("B04_Surface_Model_Path")}: ${model.model_file_path ?? "-"}`;
      meta.append(resolution, path);

      card.append(head, meta);
      modelList.append(card);
    }
  }

  function getProjectId(): string | null {
    const projectId = localStorage.getItem(CURRENT_PROJECT_ID_KEY);
    if (!projectId) {
      inputFileField.setError(L("B04_Surface_Error_Project"));
      showToast(L("B04_Surface_Error_Project"), "error");
    }
    return projectId;
  }

  async function onB04_Surface_Analyze_Click(): Promise<void> {
    const projectId = getProjectId();
    if (!projectId) return;

    const rawId = inputFileField.input.value.trim();
    const inputFileId = Number(rawId);
    if (!rawId || !Number.isInteger(inputFileId) || inputFileId <= 0) {
      inputFileField.setError(L("B04_Surface_Error_InputId"));
      return;
    }
    if (filterGroup.selected.size === 0 || methodGroup.selected.size === 0) {
      inputFileField.setError(L("B04_Surface_Error_Selection"));
      return;
    }
    inputFileField.setError();

    showLoadingOverlay();
    try {
      const response = await analyzeSurface(projectId, {
        input_file_id: inputFileId,
        source_filters: [...filterGroup.selected],
        methods: [...methodGroup.selected],
        force: forceBox.checked,
      });
      showToast(
        `${L("B04_Surface_Analyze_Success")} (${response.surface_model_ids.length})`,
        "success",
      );
      await loadModels(projectId);
    } catch (error) {
      const detail = error instanceof Error ? error.message : L("B04_Surface_Analyze_Failed");
      inputFileField.setError(`${L("B04_Surface_Analyze_Failed")} ${detail}`);
      showToast(L("B04_Surface_Analyze_Failed"), "error");
    } finally {
      hideLoadingOverlay();
    }
  }

  async function loadModels(projectId: string): Promise<void> {
    showLoadingOverlay();
    try {
      const response = await listSurfaceModels(projectId);
      renderModels(response.models);
    } catch {
      showToast(L("B04_Surface_Load_Failed"), "error");
    } finally {
      hideLoadingOverlay();
    }
  }

  async function onB04_Surface_Refresh_Click(): Promise<void> {
    const projectId = getProjectId();
    if (projectId) await loadModels(projectId);
  }

  renderModels([]);
  root.replaceChildren(shell.root);

  const initialProjectId = localStorage.getItem(CURRENT_PROJECT_ID_KEY);
  if (initialProjectId) void loadModels(initialProjectId);
}