import { stationApi } from "./api.js";
import { el, escapeHtml, setBanner } from "./dom.js";

const STATION_TYPES = [
  "load",
  "dry_in",
  "dry_step",
  "dry_out",
  "fire_in",
  "fire_step",
  "fire_out",
  "transfer",
  "unload",
  "return",
];

const SIGNAL_ROLES = ["presence", "vacancy", "arrived", "allow_in", "done", "fault"];

const stations = new Map();
const expanded = new Set();
let stationDetails = new Map(); // station_id -> { signals: [...] }
let editing = null; // station_id being edited inline
let creating = false;

function renderForm(initial) {
  const data = initial || {};
  return `
    <form class="config-form" data-form="station">
      <div class="form-row">
        <label>Code<input name="code" value="${escapeHtml(data.code)}" required maxlength="100" /></label>
        <label>名称<input name="name" value="${escapeHtml(data.name)}" required maxlength="100" /></label>
      </div>
      <div class="form-row">
        <label>线路<input name="line_code" value="${escapeHtml(data.line_code)}" maxlength="50" /></label>
        <label>段分组<input name="segment_code" value="${escapeHtml(data.segment_code)}" maxlength="50" /></label>
      </div>
      <div class="form-row">
        <label>工位类型
          <select name="station_type" required>
            ${STATION_TYPES.map(
              (t) => `<option value="${t}"${data.station_type === t ? " selected" : ""}>${t}</option>`,
            ).join("")}
          </select>
        </label>
        <label class="form-check">
          <input type="checkbox" name="enabled" ${data.enabled === false ? "" : "checked"} />
          启用
        </label>
      </div>
      <label>说明<textarea name="description" maxlength="500">${escapeHtml(data.description)}</textarea></label>
      <div class="form-actions">
        <button type="button" data-action="cancel-form" class="secondary">取消</button>
        <button type="submit">保存</button>
      </div>
    </form>
  `;
}

function renderSignalForm() {
  return `
    <form class="config-form signal-form" data-form="signal">
      <div class="form-row">
        <label>角色
          <select name="signal_role" required>
            ${SIGNAL_ROLES.map((r) => `<option value="${r}">${r}</option>`).join("")}
          </select>
        </label>
        <label>Point ID<input name="point_id" placeholder="UUID 或留空走推导" /></label>
      </div>
      <div class="form-row">
        <label>推导来源角色
          <select name="derived_from_role">
            <option value="">(none)</option>
            ${SIGNAL_ROLES.map((r) => `<option value="${r}">${r}</option>`).join("")}
          </select>
        </label>
        <label class="form-check">
          <input type="checkbox" name="invert_value" />取反
        </label>
      </div>
      <div class="form-actions">
        <button type="submit">绑定 / 更新</button>
      </div>
    </form>
  `;
}

function renderSignals(signals) {
  if (!signals?.length) {
    return `<div class="muted card-empty">未绑定信号</div>`;
  }
  return `
    <table class="config-table">
      <thead>
        <tr><th>角色</th><th>Point</th><th>推导</th><th>取反</th><th></th></tr>
      </thead>
      <tbody>
        ${signals
          .map(
            (sig) => `
              <tr>
                <td>${escapeHtml(sig.signal_role)}</td>
                <td class="mono">${escapeHtml(sig.point_id || "")}</td>
                <td>${escapeHtml(sig.derived_from_role || "")}</td>
                <td>${sig.invert_value ? "是" : "否"}</td>
                <td><button data-action="delete-signal" data-role="${escapeHtml(sig.signal_role)}" class="secondary">解绑</button></td>
              </tr>
            `,
          )
          .join("")}
      </tbody>
    </table>
  `;
}

function renderRow(station) {
  const isExpanded = expanded.has(station.id);
  const isEditing = editing === station.id;
  const detail = stationDetails.get(station.id);
  return `
    <article class="config-row" data-station-id="${station.id}">
      <header class="row-head">
        <div class="row-title">
          <strong>${escapeHtml(station.code)}</strong>
          <span class="muted">${escapeHtml(station.name)}</span>
          ${station.line_code ? `<span class="badge">${escapeHtml(station.line_code)}</span>` : ""}
          <span class="badge">${escapeHtml(station.station_type)}</span>
          ${station.enabled ? "" : `<span class="badge badge-warn">已禁用</span>`}
        </div>
        <div class="row-actions">
          <button data-action="toggle">${isExpanded ? "收起" : "信号"}</button>
          <button data-action="edit">${isEditing ? "取消" : "编辑"}</button>
          <button data-action="delete" class="danger">删除</button>
        </div>
      </header>
      ${isEditing ? `<div class="row-edit">${renderForm(station)}</div>` : ""}
      ${
        isExpanded
          ? `<div class="row-body">
              ${renderSignals(detail?.signals)}
              ${renderSignalForm()}
            </div>`
          : ""
      }
    </article>
  `;
}

function renderAll() {
  const root = el("stationList");
  if (!root) return;
  const list = Array.from(stations.values()).sort((a, b) => a.code.localeCompare(b.code));
  root.innerHTML = `
    ${creating ? `<div class="config-row creating">${renderForm({})}</div>` : ""}
    ${list.length === 0 ? `<div class="muted card-empty">尚无工位</div>` : list.map(renderRow).join("")}
  `;
}

function formToPayload(form) {
  const data = Object.fromEntries(new FormData(form));
  const payload = {
    code: data.code?.trim(),
    name: data.name?.trim(),
    station_type: data.station_type,
    enabled: form.elements.enabled.checked,
  };
  if (data.line_code) payload.line_code = data.line_code.trim();
  if (data.segment_code) payload.segment_code = data.segment_code.trim();
  if (data.description) payload.description = data.description;
  return payload;
}

function signalFormToPayload(form) {
  const data = Object.fromEntries(new FormData(form));
  const payload = { signal_role: data.signal_role };
  if (data.point_id) payload.point_id = data.point_id.trim();
  if (data.derived_from_role) payload.derived_from_role = data.derived_from_role;
  payload.invert_value = form.elements.invert_value.checked;
  return payload;
}

async function refreshDetail(stationId) {
  try {
    const detail = await stationApi.detail(stationId);
    stationDetails.set(stationId, { signals: detail.signals || [] });
  } catch (err) {
    setBanner(el("stationList"), err.message || String(err), "error");
  }
}

async function handleClick(event) {
  const button = event.target.closest("button[data-action]");
  if (!button) return;
  const action = button.dataset.action;
  const row = event.target.closest(".config-row");
  const stationId = row?.dataset?.stationId;

  switch (action) {
    case "cancel-form":
      creating = false;
      editing = null;
      return renderAll();
    case "toggle":
      if (!stationId) return;
      if (expanded.has(stationId)) {
        expanded.delete(stationId);
      } else {
        expanded.add(stationId);
        await refreshDetail(stationId);
      }
      return renderAll();
    case "edit":
      editing = editing === stationId ? null : stationId;
      return renderAll();
    case "delete":
      if (!stationId) return;
      if (!window.confirm("确认删除该工位？此操作不可恢复。")) return;
      try {
        await stationApi.remove(stationId);
        stations.delete(stationId);
        expanded.delete(stationId);
        if (editing === stationId) editing = null;
        renderAll();
        setBanner(el("stationList"), "工位已删除", "info");
      } catch (err) {
        setBanner(el("stationList"), err.message || String(err), "error");
      }
      return;
    case "delete-signal": {
      if (!stationId) return;
      const role = button.dataset.role;
      try {
        await stationApi.deleteSignal(stationId, role);
        await refreshDetail(stationId);
        renderAll();
        setBanner(el("stationList"), `已解除 ${role} 绑定`, "info");
      } catch (err) {
        setBanner(el("stationList"), err.message || String(err), "error");
      }
      return;
    }
    default:
      return;
  }
}

async function handleSubmit(event) {
  const form = event.target.closest("form[data-form]");
  if (!form) return;
  event.preventDefault();
  const row = form.closest(".config-row");
  const stationId = row?.dataset?.stationId;

  if (form.dataset.form === "station") {
    const payload = formToPayload(form);
    try {
      if (stationId && editing === stationId) {
        await stationApi.update(stationId, payload);
        setBanner(el("stationList"), "工位已更新", "info");
      } else {
        await stationApi.create(payload);
        setBanner(el("stationList"), "工位已创建", "info");
      }
      creating = false;
      editing = null;
      await loadStations();
    } catch (err) {
      setBanner(el("stationList"), err.message || String(err), "error");
    }
    return;
  }

  if (form.dataset.form === "signal") {
    if (!stationId) return;
    const payload = signalFormToPayload(form);
    try {
      await stationApi.upsertSignal(stationId, payload);
      await refreshDetail(stationId);
      renderAll();
      setBanner(el("stationList"), "信号绑定已保存", "info");
    } catch (err) {
      setBanner(el("stationList"), err.message || String(err), "error");
    }
  }
}

export async function loadStations() {
  try {
    const rows = await stationApi.list();
    stations.clear();
    rows.forEach((s) => stations.set(s.id, s));
    renderAll();
  } catch (err) {
    setBanner(el("stationList"), err.message || String(err), "error");
  }
}

export function bindStationEvents() {
  const root = el("stationList");
  if (root) {
    root.addEventListener("click", handleClick);
    root.addEventListener("submit", handleSubmit);
  }
  const addBtn = el("addStationBtn");
  if (addBtn) {
    addBtn.addEventListener("click", () => {
      creating = !creating;
      editing = null;
      renderAll();
    });
  }
  const refreshBtn = el("refreshStationsBtn");
  if (refreshBtn) refreshBtn.addEventListener("click", () => loadStations());
}