import { createSession, getWebInfo, recentDirs, gitRoot } from "./api.js";
import { attachDirAutocomplete, type DirAutocompleteHandle } from "./dirAutocomplete.js";
import { generateName } from "./names.js";
import type {
  CreateSessionRequest,
  DaemonInfo,
  RecentDir,
  Session,
  SpawnPreset,
} from "./types.js";

/** Seed values for the spawn form — used by "clone" to reopen the dialog with
 * the same daemon, cwd, command, name, and label as an existing session. */
export interface SpawnPrefill {
  daemon_id?: string;
  cwd?: string;
  command?: string;
  name?: string;
  label?: string;
}

/** Built-ins used when the daemon's `/api/web/info` presets can't be fetched
 * (older daemon, transient error). Mirrors `maestro_config::builtin_presets`. */
const FALLBACK_PRESETS: SpawnPreset[] = [
  { id: "claude", label: "Claude", command: "claude" },
  { id: "opencode", label: "opencode", command: "opencode" },
  { id: "zsh", label: "Shell", command: "zsh" },
  { id: "custom", label: "Custom…", command: "" },
];

/** How many host tiles to show before collapsing the rest behind "More…". */
const MAX_HOST_TILES = 4;

export function openSpawnModal(
  daemons: Map<string, DaemonInfo>,
  prefill?: SpawnPrefill,
  sessions?: Map<string, Session>,
): void {
  const existing = document.getElementById("modal-host");
  if (existing) existing.remove();

  const host = document.createElement("div");
  host.id = "modal-host";
  host.className = "modal-backdrop";
  host.innerHTML = `
    <div class="modal spawn-modal" role="dialog" aria-modal="true" aria-labelledby="spawn-title">
      <header class="modal-header">
        <h2 id="spawn-title">Spawn session</h2>
        <button type="button" class="btn btn-icon close" aria-label="Close">✕</button>
      </header>
      <form class="modal-body" id="spawn-form">
        <div class="field">
          <span class="field-label">Host</span>
          <div class="tile-row" id="host-tiles"></div>
        </div>
        <div class="field">
          <span class="field-label">Command</span>
          <div class="tile-row" id="cmd-tiles"></div>
          <input class="raw-input" id="cmd-raw" name="command_raw" type="text" hidden
                 placeholder="bash -l" autocomplete="off" />
        </div>
        <div class="field">
          <span class="field-label">Working directory</span>
          <div class="picker" id="recents"></div>
          <div class="raw-wrap" id="cwd-raw-wrap" hidden>
            <input class="raw-input" id="cwd-raw" name="cwd_raw" type="text"
                   placeholder="/home/user/project" inputmode="text" autocomplete="off" />
          </div>
        </div>
        <fieldset class="worktree">
          <legend>
            <label class="row-inline">
              <input type="checkbox" name="worktree_enabled" id="wt-enabled" />
              Create git worktree
            </label>
          </legend>
          <p class="wt-hint" id="wt-hint" hidden></p>
          <div class="wt-body" id="wt-body" hidden>
            <p class="wt-repo" id="wt-repo"></p>
            <label>
              Branch
              <input name="worktree_branch" type="text" placeholder="feat/foo" autocomplete="off" />
            </label>
            <label class="row-inline">
              <input type="checkbox" name="worktree_cleanup_on_kill" />
              Remove worktree when session is killed
            </label>
          </div>
        </fieldset>
        <div class="field">
          <span class="field-label">Name</span>
          <div class="name-row">
            <input name="name" type="text" autocomplete="off" />
            <button type="button" class="btn btn-icon reroll" id="reroll" aria-label="Generate a new name" title="New name">↻</button>
          </div>
        </div>
        <label>
          Label (optional)
          <input name="label" type="text" placeholder="personal/maestro" autocomplete="off" />
        </label>
        <p class="form-error" role="alert" aria-live="polite"></p>
        <div class="modal-actions">
          <button type="button" class="btn btn-ghost cancel">Cancel</button>
          <button type="submit" class="btn btn-primary">Spawn</button>
        </div>
      </form>
    </div>
  `;
  document.body.appendChild(host);

  const form = host.querySelector("#spawn-form") as HTMLFormElement;
  const errEl = form.querySelector(".form-error") as HTMLElement;
  const hostTiles = host.querySelector("#host-tiles") as HTMLElement;
  const cmdTiles = host.querySelector("#cmd-tiles") as HTMLElement;
  const cmdRaw = host.querySelector("#cmd-raw") as HTMLInputElement;
  const recentsEl = host.querySelector("#recents") as HTMLElement;
  const cwdRawWrap = host.querySelector("#cwd-raw-wrap") as HTMLElement;
  const cwdRaw = host.querySelector("#cwd-raw") as HTMLInputElement;
  const wtEnabled = host.querySelector("#wt-enabled") as HTMLInputElement;
  const wtHint = host.querySelector("#wt-hint") as HTMLElement;
  const wtBody = host.querySelector("#wt-body") as HTMLElement;
  const wtRepo = host.querySelector("#wt-repo") as HTMLElement;
  const branchInput = host.querySelector("input[name=worktree_branch]") as HTMLInputElement;
  const nameInput = host.querySelector("input[name=name]") as HTMLInputElement;

  // ---- form state ------------------------------------------------------
  let selectedHostId = "";
  let presets: SpawnPreset[] = FALLBACK_PRESETS;
  let selectedPresetId = "";
  let command = ""; // resolved command (preset's, or the raw custom input)
  let cwd = ""; // chosen working directory
  let inferredBaseRepo: string | null = null; // from the gitroot probe
  let probeToken = 0; // guards async gitroot probes against races
  let showAllHosts = false;
  // A clone's cwd, applied once the (async) recents load for the initial host
  // settles — so the fetch can't race past and clobber the seeded directory.
  let cloneCwd: string | null = prefill?.cwd ?? null;

  // ---- name ------------------------------------------------------------
  nameInput.value = prefill?.name ?? generateName();
  (host.querySelector("#reroll") as HTMLButtonElement).addEventListener("click", () => {
    nameInput.value = generateName();
  });

  // ---- command tiles ---------------------------------------------------
  function selectPreset(id: string): void {
    selectedPresetId = id;
    const preset = presets.find((p) => p.id === id);
    const isCustom = !preset || preset.command === "";
    cmdRaw.hidden = !isCustom;
    if (isCustom) {
      command = cmdRaw.value.trim();
      cmdRaw.focus();
    } else {
      command = preset!.command;
    }
    for (const tile of cmdTiles.querySelectorAll(".tile")) {
      tile.classList.toggle("is-active", (tile as HTMLElement).dataset.id === id);
    }
  }

  function renderCommandTiles(): void {
    cmdTiles.replaceChildren();
    for (const p of presets) {
      const tile = document.createElement("button");
      tile.type = "button";
      tile.className = "tile";
      tile.dataset.id = p.id;
      tile.innerHTML = `<span class="tile-label">${escapeHtml(p.label)}</span>`;
      tile.addEventListener("click", () => selectPreset(p.id));
      cmdTiles.appendChild(tile);
    }
  }

  cmdRaw.addEventListener("input", () => {
    if (selectedPresetId === "custom" || presets.find((p) => p.id === selectedPresetId)?.command === "") {
      command = cmdRaw.value.trim();
    }
  });

  // Presets ride `/api/web/info`; render fallbacks immediately, then refine.
  renderCommandTiles();
  applyInitialCommand();
  getWebInfo()
    .then((info) => {
      if (info.presets?.length) {
        presets = info.presets;
        renderCommandTiles();
        applyInitialCommand();
      }
    })
    .catch(() => {
      /* keep fallbacks */
    });

  // Pick a sensible starting command: a clone's command (matched to a preset or
  // dropped into custom), else the first non-custom preset.
  function applyInitialCommand(): void {
    const wanted = prefill?.command;
    if (wanted) {
      const match = presets.find((p) => p.command === wanted && p.command !== "");
      if (match) {
        selectPreset(match.id);
      } else {
        const custom = presets.find((p) => p.command === "");
        cmdRaw.value = wanted;
        selectPreset(custom ? custom.id : "custom");
        command = wanted;
      }
      return;
    }
    const first = presets.find((p) => p.command !== "");
    if (first) selectPreset(first.id);
  }

  // ---- working-directory picker ---------------------------------------
  function showRawCwd(prefillValue?: string): void {
    cwdRawWrap.hidden = false;
    if (prefillValue != null) cwd = prefillValue;
    cwdRaw.value = cwd;
    markActiveRecent(null);
    cwdRaw.focus();
    cwdRaw.select();
  }

  cwdRaw.addEventListener("input", () => {
    cwd = cwdRaw.value.trim();
    if (wtEnabled.checked) probeGitRoot();
  });

  function markActiveRecent(activeCwd: string | null): void {
    for (const row of recentsEl.querySelectorAll(".recent-row")) {
      row.classList.toggle(
        "is-active",
        (row as HTMLElement).dataset.cwd === activeCwd,
      );
    }
  }

  function selectRecent(dir: RecentDir): void {
    cwd = dir.cwd;
    cwdRawWrap.hidden = true;
    markActiveRecent(dir.cwd);
    // Picking a recent dir can pre-select the command it was last used with.
    const match = presets.find((p) => p.command === dir.last_command && p.command !== "");
    if (match) selectPreset(match.id);
    if (wtEnabled.checked) probeGitRoot();
  }

  async function loadRecents(): Promise<void> {
    recentsEl.replaceChildren(loadingRow());
    let dirs: RecentDir[] = [];
    try {
      dirs = (await recentDirs(selectedHostId)).dirs ?? [];
    } catch {
      dirs = [];
    }
    recentsEl.replaceChildren();
    for (const dir of dirs) {
      recentsEl.appendChild(recentRow(dir));
    }
    // Persistent escape hatch + empty-history fallback.
    recentsEl.appendChild(otherDirRow());
    if (cloneCwd) {
      // A clone seeds the directory verbatim into the raw input, regardless of
      // this host's history.
      showRawCwd(cloneCwd);
      cloneCwd = null;
    } else if (dirs.length === 0) {
      // No history: default to raw input prefilled with the host's home dir.
      const home = daemons.get(selectedHostId)?.home_dir ?? "";
      showRawCwd(home);
    } else {
      cwdRawWrap.hidden = true;
    }
  }

  function recentRow(dir: RecentDir): HTMLElement {
    const row = document.createElement("button");
    row.type = "button";
    row.className = "recent-row";
    row.dataset.cwd = dir.cwd;
    row.innerHTML = `
      <span class="recent-dir">${escapeHtml(dir.cwd)}</span>
      <span class="recent-cmd">${escapeHtml(dir.last_command)}</span>`;
    row.addEventListener("click", () => selectRecent(dir));
    return row;
  }

  function otherDirRow(): HTMLElement {
    const row = document.createElement("button");
    row.type = "button";
    row.className = "recent-row recent-other";
    row.innerHTML = `<span class="recent-dir">Other directory…</span>`;
    row.addEventListener("click", () => {
      const home = daemons.get(selectedHostId)?.home_dir ?? "";
      showRawCwd(cwd || home);
    });
    return row;
  }

  function loadingRow(): HTMLElement {
    const p = document.createElement("p");
    p.className = "picker-loading";
    p.textContent = "Loading recent directories…";
    return p;
  }

  // ---- worktree (branch-only; base_repo inferred via /gitroot) ----------
  async function probeGitRoot(): Promise<void> {
    const token = ++probeToken;
    if (!cwd) {
      inferredBaseRepo = null;
      wtBody.hidden = true;
      wtHint.hidden = false;
      wtHint.textContent = "Choose a working directory first.";
      return;
    }
    wtHint.hidden = false;
    wtHint.textContent = "Checking for a git repository…";
    wtBody.hidden = true;
    let root: string | undefined;
    try {
      root = (await gitRoot(selectedHostId, cwd)).root;
    } catch {
      root = undefined;
    }
    if (token !== probeToken) return; // a newer probe superseded us
    if (root) {
      inferredBaseRepo = root;
      wtHint.hidden = true;
      wtBody.hidden = false;
      wtRepo.textContent = `repo: ${root} (inferred)`;
    } else {
      inferredBaseRepo = null;
      wtEnabled.checked = false;
      wtBody.hidden = true;
      wtHint.hidden = false;
      wtHint.textContent = "Not inside a git repository — pick a dir in a repo to use a worktree.";
    }
  }

  wtEnabled.addEventListener("change", () => {
    if (wtEnabled.checked) {
      probeGitRoot();
    } else {
      inferredBaseRepo = null;
      wtBody.hidden = true;
      wtHint.hidden = true;
    }
  });

  // ---- host tiles ------------------------------------------------------
  // Order hosts by most-recently-spawned-on first, so the common case is the
  // pre-selected tile.
  function orderedHosts(): DaemonInfo[] {
    const list = [...daemons.values()];
    const lastUsed = new Map<string, number>();
    for (const s of sessions?.values() ?? []) {
      const t = Date.parse(s.created_at);
      if (Number.isFinite(t)) {
        lastUsed.set(s.daemon_id, Math.max(lastUsed.get(s.daemon_id) ?? 0, t));
      }
    }
    return list.sort((a, b) => (lastUsed.get(b.daemon_id) ?? 0) - (lastUsed.get(a.daemon_id) ?? 0));
  }

  function selectHost(id: string): void {
    selectedHostId = id;
    for (const tile of hostTiles.querySelectorAll(".tile")) {
      tile.classList.toggle("is-active", (tile as HTMLElement).dataset.id === id);
    }
    // Recents + any worktree inference are host-scoped — refresh on change.
    cwd = "";
    inferredBaseRepo = null;
    if (wtEnabled.checked) {
      wtEnabled.checked = false;
      wtBody.hidden = true;
      wtHint.hidden = true;
    }
    void loadRecents();
  }

  function renderHostTiles(): void {
    hostTiles.replaceChildren();
    const ordered = orderedHosts();
    if (ordered.length === 0) {
      const empty = document.createElement("p");
      empty.className = "picker-loading";
      empty.textContent = "(no daemons connected)";
      hostTiles.appendChild(empty);
      return;
    }
    const visible = showAllHosts ? ordered : ordered.slice(0, MAX_HOST_TILES);
    for (const d of visible) {
      const tile = document.createElement("button");
      tile.type = "button";
      tile.className = "tile tile-host";
      tile.dataset.id = d.daemon_id;
      tile.innerHTML = `
        <span class="tile-label">${escapeHtml(d.hostname)}</span>
        <span class="tile-sub">${escapeHtml(d.daemon_id)}</span>`;
      tile.addEventListener("click", () => selectHost(d.daemon_id));
      hostTiles.appendChild(tile);
    }
    if (!showAllHosts && ordered.length > MAX_HOST_TILES) {
      const more = document.createElement("button");
      more.type = "button";
      more.className = "tile tile-more";
      more.innerHTML = `<span class="tile-label">More…</span>`;
      more.addEventListener("click", () => {
        showAllHosts = true;
        renderHostTiles();
        // Keep the current selection highlighted after re-render.
        if (selectedHostId) {
          hostTiles
            .querySelector(`.tile[data-id="${cssEscape(selectedHostId)}"]`)
            ?.classList.add("is-active");
        }
      });
      hostTiles.appendChild(more);
    }
  }

  renderHostTiles();
  // Pre-select: a clone's host if present & connected, else the most-recent.
  const ordered = orderedHosts();
  const initialHost =
    prefill?.daemon_id && daemons.has(prefill.daemon_id)
      ? prefill.daemon_id
      : ordered[0]?.daemon_id;
  if (initialHost) selectHost(initialHost);

  // ---- clone seed ------------------------------------------------------
  if (prefill) {
    (host.querySelector("#spawn-title") as HTMLElement).textContent = "Clone session";
    (host.querySelector("input[name=label]") as HTMLInputElement).value = prefill.label ?? "";
    // The cwd itself is applied by loadRecents once the initial host's recents
    // settle (see `cloneCwd`), so a slow fetch can't clobber it.
  }

  // ---- live dir autocomplete on the raw cwd input (NAP-329) ------------
  const autocompletes: DirAutocompleteHandle[] = [
    attachDirAutocomplete(cwdRaw, () => selectedHostId),
  ];

  // ---- lifecycle -------------------------------------------------------
  const close = () => {
    autocompletes.forEach((a) => a.destroy());
    host.remove();
  };
  host.querySelector(".close")?.addEventListener("click", close);
  host.querySelector(".cancel")?.addEventListener("click", close);
  host.addEventListener("click", (e) => {
    if (e.target === host) close();
  });
  window.addEventListener(
    "keydown",
    (e) => {
      if (e.key === "Escape") close();
    },
    { once: true },
  );

  // ---- submit ----------------------------------------------------------
  form.addEventListener("submit", async (e) => {
    e.preventDefault();
    errEl.textContent = "";
    if (!selectedHostId) {
      errEl.textContent = "Pick a host.";
      return;
    }
    if (!cwd) {
      errEl.textContent = "Pick a working directory.";
      return;
    }
    if (!command) {
      errEl.textContent = "Pick a command (or fill the custom command).";
      return;
    }

    const metadata: Record<string, unknown> = {};
    const name = nameInput.value.trim();
    const label = (host.querySelector("input[name=label]") as HTMLInputElement).value.trim();
    if (name) metadata.name = name;
    if (label) metadata.label = label;

    const req: CreateSessionRequest = {
      daemon_id: selectedHostId,
      cwd,
      command,
      metadata,
    };

    if (wtEnabled.checked) {
      const branch = branchInput.value.trim();
      if (!inferredBaseRepo) {
        errEl.textContent = "Worktree needs a directory inside a git repository.";
        return;
      }
      if (!branch) {
        errEl.textContent = "Worktree requires a branch name.";
        return;
      }
      req.worktree = {
        base_repo: inferredBaseRepo,
        branch,
        cleanup_on_kill: Boolean(
          (host.querySelector("input[name=worktree_cleanup_on_kill]") as HTMLInputElement).checked,
        ),
      };
    }

    const submitBtn = form.querySelector("button[type=submit]") as HTMLButtonElement;
    submitBtn.disabled = true;
    try {
      const session = await createSession(req);
      close();
      location.hash = `#/attach/${encodeURIComponent(session.id)}`;
    } catch (err) {
      errEl.textContent = (err as Error).message;
      submitBtn.disabled = false;
    }
  });
}

function escapeHtml(s: string): string {
  return s
    .replace(/&/g, "&amp;")
    .replace(/</g, "&lt;")
    .replace(/>/g, "&gt;")
    .replace(/"/g, "&quot;");
}

/** Escape a string for use inside a CSS attribute selector. Uses the native
 * `CSS.escape` when available, with a conservative fallback. */
function cssEscape(s: string): string {
  const cssApi = (globalThis as { CSS?: { escape?: (v: string) => string } }).CSS;
  if (cssApi?.escape) return cssApi.escape(s);
  return s.replace(/["\\]/g, "\\$&");
}