/* =============================================================================
 * B01_Dashboard_UI_ProjectList.ts
 * 대시보드 「프로젝트」 세부 페이지(요구 369~374 · PLAN 548-1) — 툴바(찾기 · 종류 칩 · 담당 · 보기 ·
 *   카드/표/칸반 · [+ 새 프로젝트]) + 고른 보기. 고른 보기는 계정 취향(`aislo:pref:`)으로 기억.
 *   칸반은 9 개 넘을 때만 · 칸은 서버가 단계 상태로 나눔(끌기 없음).
 * ========================================================================== */

import "./B01_Dashboard_UI_Style_Projects.css";
import { createButton, showToast } from "@ui/ui_template_elements";
import { el } from "@ui/ui_template_elements_base";
import { readByKey, writeByKey } from "../A00_Common/b_page_state";
import type { DashboardUser } from "./B01_Dashboard_Api_Fetch";
import { fetchOverviewProjects, type OverviewProject } from "./B01_Dashboard_Api_Projects";
import { openNewProjectPicker } from "./B01_Dashboard_UI_NewProject";
import { KINDS } from "./B01_Dashboard_UI_ProjectList_Parts";
import { cardGrid, kanbanBoard, projectRows } from "./B01_Dashboard_UI_ProjectList_Views";

/** 등록부 ctx(546) 가운데 이 페이지가 쓰는 것 */
export interface ProjectViewCtx {
  me: DashboardUser;
  companyId: number | null;
  go: (view: string, params?: Record<string, string>) => void;
}

type ViewMode = "card" | "table" | "kanban";
type Scope = "mine" | "company";

/** 칸반이 열리는 수 — 넘으면 [칸반] 단추 */
export const KANBAN_MIN = 10;
const PREF_VIEW = "aislo:pref:b01.projects.view";
const PREF_SCOPE = "aislo:pref:b01.projects.scope";

interface ListState {
  scope: Scope;
  view: ViewMode;
  kind: string;
  manager: string;
  query: string;
  projects: OverviewProject[];
}

/** 거르기 — 종류 · 담당 · 찾기(이름 · 지역) */
export function filterProjects(
  projects: OverviewProject[],
  kind: string,
  manager: string,
  query: string,
): OverviewProject[] {
  const q = query.trim().toLowerCase();
  return projects.filter(
    (p) =>
      (!kind || (p.project_kind ?? "ROAD") === kind) &&
      (!manager || p.manager_name === manager) &&
      (!q || `${p.name} ${p.region ?? ""}`.toLowerCase().includes(q)),
  );
}

function segment<T extends string>(
  items: { key: T; label: string }[],
  active: T,
  onPick: (key: T) => void,
): HTMLElement {
  const seg = el("span", { className: "b01-proj-seg", attrs: { role: "group" } });
  for (const item of items) {
    const button = el("button", {
      className: item.key === active ? "is-on" : "",
      text: item.label,
      attrs: { type: "button", "data-key": item.key },
    });
    button.addEventListener("click", () => onPick(item.key));
    seg.append(button);
  }
  return seg;
}

function chip(label: string, on: boolean, onClick?: () => void, soon = false): HTMLElement {
  const button = el("button", {
    className: `b01-proj-chip${on ? " is-on" : ""}${soon ? " is-soon" : ""}`,
    text: label,
    attrs: { type: "button" },
  });
  button.addEventListener("click", () => (soon ? showToast(label) : onClick?.()));
  return button;
}

/** 「프로젝트」 페이지 — 등록부 mount */
export function mountProjectList(host: HTMLElement, ctx: ProjectViewCtx): () => void {
  let alive = true;
  const state: ListState = {
    scope: readByKey(PREF_SCOPE) === "mine" ? "mine" : "company",
    view: (readByKey(PREF_VIEW) as ViewMode | null) ?? "card",
    kind: "",
    manager: "",
    query: "",
    projects: [],
  };
  const root = el("div", { className: "b01-proj" });
  const head = el("div", { className: "b01-proj-head" });
  const tools = el("div", { className: "b01-proj-tools" });
  const body = el("div", { className: "b01-proj-body" });
  root.append(head, tools, body);
  host.replaceChildren(root);

  const search = el("input", {
    className: "b01-proj-search",
    attrs: { type: "search", placeholder: "이름 · 지역 찾기" },
  });
  search.addEventListener("input", () => {
    state.query = search.value;
    paintBody();
  });

  const open = (project: OverviewProject): void => ctx.go("project", { id: project.id });

  function paintHead(): void {
    const kanbanOk = state.projects.length >= KANBAN_MIN;
    const views: { key: ViewMode; label: string }[] = [
      { key: "card", label: "카드" },
      { key: "table", label: "표" },
      ...(kanbanOk ? [{ key: "kanban" as ViewMode, label: "칸반" }] : []),
    ];
    head.replaceChildren(
      el("h2", { text: "프로젝트" }),
      el("span", { className: "b01-proj-count", text: String(state.projects.length) }),
      el("span", { className: "b01-proj-sp" }),
      segment(views, shownView(), (key) => {
        state.view = key;
        writeByKey(PREF_VIEW, key);
        paintHead();
        paintBody();
      }),
      createButton({ label: "+ 새 프로젝트", onClick: () => void openNewProjectPicker() }),
    );
  }

  /** 기억한 보기가 칸반인데 9 개 이하 = 카드 */
  const shownView = (): ViewMode =>
    state.view === "kanban" && state.projects.length < KANBAN_MIN ? "card" : state.view;

  function paintTools(): void {
    const count = (kind: string): number =>
      state.projects.filter((p) => (p.project_kind ?? "ROAD") === kind).length;
    const chips = [
      chip(`전체 ${state.projects.length}`, !state.kind, () => pickKind("")),
      ...KINDS.map((k) =>
        "soon" in k
          ? chip(`${k.label()} · 준비 중`, false, undefined, true)
          : chip(`${k.label()} ${count(k.key)}`, state.kind === k.key, () => pickKind(k.key)),
      ),
    ];
    const managers = [...new Set(state.projects.map((p) => p.manager_name).filter(Boolean))];
    const select = el("select", { className: "b01-proj-select", attrs: { "aria-label": "담당" } });
    select.append(new Option("담당 : 전체", ""), ...managers.map((m) => new Option(m!, m!)));
    select.value = state.manager;
    select.addEventListener("change", () => {
      state.manager = select.value;
      paintBody();
    });
    const scope = segment(
      [
        { key: "mine" as Scope, label: "내 것" },
        { key: "company" as Scope, label: "회사 전체" },
      ],
      state.scope,
      (key) => {
        state.scope = key;
        writeByKey(PREF_SCOPE, key);
        void load();
      },
    );
    tools.replaceChildren(
      search,
      ...chips,
      el("span", { className: "b01-proj-sp" }),
      select,
      scope,
    );
  }

  function pickKind(kind: string): void {
    state.kind = kind;
    paintTools();
    paintBody();
  }

  function paintBody(): void {
    const shown = filterProjects(state.projects, state.kind, state.manager, state.query);
    if (!shown.length) {
      body.replaceChildren(
        el("p", {
          className: "b01-proj-empty",
          text: state.projects.length
            ? "조건에 맞는 프로젝트가 없습니다."
            : "아직 프로젝트가 없습니다. [+ 새 프로젝트]로 시작합니다.",
        }),
      );
      return;
    }
    const view = shownView();
    body.replaceChildren(
      view === "table"
        ? projectRows(shown, ctx.me, open)
        : view === "kanban"
          ? kanbanBoard(shown, open)
          : cardGrid(shown, open),
    );
  }

  async function load(): Promise<void> {
    body.replaceChildren(el("p", { className: "b01-proj-empty", text: "불러오는 중…" }));
    try {
      const projects = await fetchOverviewProjects(state.scope, ctx.companyId);
      if (!alive) return;
      state.projects = projects;
    } catch (error) {
      if (!alive) return;
      state.projects = [];
      showToast(error instanceof Error ? error.message : String(error), "error");
    }
    paintHead();
    paintTools();
    paintBody();
  }

  paintHead();
  paintTools();
  void load();
  return () => {
    alive = false;
  };
}