/**
 * @file The lane's git action row: ahead/behind against the upstream, and the
 * writes `POST /api/lanes/:id/git/:action` offers that are not per-file —
 * fetch, pull, push, switch branch, create/delete a branch, publish a repo
 * that has no remote yet (a URL, then `origin` + `push -u`), and start a merge
 * (the picked branch, or the upstream once diverged; resolving it is the
 * Changes panel's job). Committing is
 * NOT here: it is the Changes panel's staged-only commit box, beside the
 * per-file stage/unstage/discard it commits — one way to commit, and it only
 * ever takes what the user staged.
 *
 * It renders at the top of the Changes panel (`LaneGitHeader`), its actions as
 * icons on the same row as the branch line, rather than in the lane card's ⋯ menu: that menu holds the rare and dangerous (`reset
 * worktree`), and these are the ordinary moves a lane needs several times an hour.
 * Nothing here decides what an action may do; the server does (pull is always
 * --ff-only, switch refuses a dirty tree), and this only reports what it said.
 * Failures print git's own text, because "! [rejected] non-fast-forward" tells
 * the user more than any sentence this file could write. The one exception
 * is `EGITAUTH` (issue #45): the dashboard's git has no terminal to prompt
 * in, so a remote wanting a login opens a form here and the SAME action is
 * resent with the typed credential — the token is never rendered back.
 * Fetch, pull, push and publish say so in a toast when they succeed; a merge,
 * a push, a publish and a branch delete ask through the themed confirm first; the rows wrap in a narrow panel.
 * @author Nguyễn Ngọc Trí Vĩ <vinnt@smartgift.vn>
 */

import { Checkbox } from "../Checkbox";
import { useRef, useState } from "react";
import { useTranslation } from "react-i18next";
import {
  ArrowDown,
  ArrowUp,
  CloudUpload,
  GitBranch,
  GitMerge,
  Plus,
  RefreshCw,
  Trash2,
  Upload,
} from "lucide-react";
import { api, gitTarget, type GitAuthNeeded } from "../../lib/api";
import { toast } from "../../lib/toast";
import { confirmDialog } from "../../lib/confirm";
import { isSubmitEnter } from "../../lib/keys";
import type { LaneGitFacts, LaneWorktree } from "../../lib/types";

type Action =
  "fetch" | "pull" | "push" | "switch" | "branch-create" | "branch-delete" | "merge" | "publish";
type RunBody = Parameters<typeof api.lanes.gitAction>[2];

const LOCAL_HOST = /^(localhost|127\.|\[::1\])/;

function Btn({
  label,
  icon,
  busy,
  disabled,
  title,
  compact,
  onClick,
}: {
  label: string;
  icon?: React.ReactNode;
  busy?: boolean;
  disabled?: boolean;
  title?: string;
  /** Icon only; the label becomes the accessible name, the hint the tooltip. */
  compact?: boolean;
  onClick: () => void;
}) {
  return (
    <button
      type="button"
      onClick={onClick}
      disabled={disabled || busy}
      title={title}
      aria-label={compact ? label : undefined}
      className={`flex items-center gap-1 rounded text-[11px] text-fg-secondary transition-colors hover:bg-surface-3 hover:text-fg-primary disabled:cursor-not-allowed disabled:opacity-40 ${
        compact ? "h-6 w-6 justify-center" : "border border-border-light px-1.5 py-0.5"
      }`}
    >
      {icon}
      {!compact && label}
    </button>
  );
}

export function LaneGitBar({
  laneId,
  session,
  source,
  git,
  onChanged,
  onNewLane,
  lead,
}: {
  laneId: number;
  /** Work in that session's own worktree (see `gitTarget`). */
  session?: string;
  /** Work in that extra folder's repo instead (`lane_sources` id, see `gitTarget`). */
  source?: number;
  git: LaneGitFacts;
  /** Rendered at the start of the action row: the header's branch line, so
   *  the facts and the buttons that act on them read as one row. */
  lead?: React.ReactNode;
  /** Called after any action that could have moved the working copy. */
  onChanged: () => void;
  /** Open the Add-lane flow for a sibling worktree of this repo, optionally on
   *  a branch this bar just created. Omitted where no such flow is reachable. */
  onNewLane?: (branch?: string) => void;
}) {
  const { t } = useTranslation(["lanes"]);
  const [busy, setBusy] = useState<Action | null>(null);
  const [error, setError] = useState<string | null>(null);
  const [switching, setSwitching] = useState(false);
  const [branches, setBranches] = useState<string[] | null>(null);
  const [worktrees, setWorktrees] = useState<LaneWorktree[]>([]);
  const [picked, setPicked] = useState("");
  const [newBranch, setNewBranch] = useState("");
  // Set when git needed a login for `action`; the form resends that action.
  const [login, setLogin] = useState<{ action: Action; auth: GitAuthNeeded } | null>(null);
  const [username, setUsername] = useState("");
  const [password, setPassword] = useState("");
  const [remember, setRemember] = useState(true);
  const [publishing, setPublishing] = useState(false);
  const [url, setUrl] = useState("");
  // The Changes panel is not keyed by lane, so this bar outlives a lane switch.
  // All of the state above describes ONE lane — a branch picked for lane A,
  // applied after switching, would move B's HEAD — so it is reset during
  // render the moment the id changes, before anything can act on it.
  const [shownLane, setShownLane] = useState(laneId);
  // One action at a time, checked synchronously: `busy` is state, and a second
  // Enter can land before the render that disables anything.
  const inFlight = useRef(false);
  if (shownLane !== laneId) {
    setShownLane(laneId);
    setBusy(null);
    setError(null);
    setSwitching(false);
    setBranches(null);
    setWorktrees([]);
    setPicked("");
    setNewBranch("");
    setLogin(null);
    setPassword("");
    setPublishing(false);
    setUrl("");
    inFlight.current = false;
  }
  const laneNow = useRef(laneId);
  laneNow.current = laneId;

  if (!git.available) return null;
  const dirty = git.dirty + git.untracked;
  const merging = !!git.merging;

  const run = async (action: Action, body?: RunBody) => {
    if (inFlight.current) return;
    inFlight.current = true;
    const lane = laneId;
    setBusy(action);
    setError(null);
    try {
      const res = await api.lanes.gitAction(gitTarget(lane, session, source), action, body || {});
      // Landed after a lane switch: every write below belongs to the lane
      // no longer shown.
      if (laneNow.current !== lane) return;
      // A merge that stopped on conflicts still succeeded in starting; the
      // Changes panel below lists the files to resolve.
      if (res?.conflicts?.length)
        setError(t("gitBar.mergeConflicts", { count: res.conflicts.length }));
      setLogin(null);
      setPassword("");
      if (action === "fetch" || action === "pull" || action === "push" || action === "publish")
        toast.success(t(`gitBar.done.${action}`));
      // The branch list this bar is showing is stale the moment a branch is
      // created, deleted or switched to, so it is re-read rather than patched.
      if (action === "publish") {
        setPublishing(false);
        setUrl("");
      } else if (action === "switch" || action.startsWith("branch-")) {
        if (action === "switch") setSwitching(false);
        else setNewBranch("");
        setPicked("");
        setBranches(null);
        await refreshBranches();
      }
      onChanged();
    } catch (err) {
      // The server appends git's own stderr to the message, so this is the
      // rejection text verbatim — hence the <pre> below rather than a line.
      // ENOREMOTE is the one refusal with no git text to show: the server's
      // sentence is English and says less than a translated one.
      const auth = (err as { code?: string; auth?: GitAuthNeeded })?.auth;
      if (laneNow.current === lane && (err as { code?: string })?.code === "EGITAUTH" && auth) {
        setLogin({ action, auth });
        setUsername((u) => u || auth.username || "");
        setPassword("");
      } else if (laneNow.current === lane)
        setError(
          (err as { code?: string })?.code === "ENOREMOTE"
            ? t("gitBar.errNoRemote")
            : err instanceof Error
              ? err.message
              : String(err)
        );
    } finally {
      if (laneNow.current === lane) {
        inFlight.current = false;
        setBusy(null);
      }
    }
  };

  const refreshBranches = async () => {
    try {
      const r = await api.lanes.gitBranches(gitTarget(laneId, session, source));
      if (laneNow.current !== laneId) return;
      setBranches(r.branches);
      setWorktrees(r.worktrees || []);
    } catch {
      if (laneNow.current === laneId) setBranches([]);
    }
  };

  const openSwitch = async () => {
    setSwitching((v) => !v);
    setError(null);
    if (branches) return;
    await refreshBranches();
  };

  // Writes that leave this machine (push, publish) or delete a ref ask
  // first. Asked HERE, at the click — never inside `run` — so the retry a git
  // login sends is not asked twice.
  const confirmRun = async (
    opts: { title: string; message: string; destructive?: boolean },
    action: Action,
    body?: RunBody
  ) => {
    if (await confirmDialog({ destructive: false, confirmLabel: opts.title, ...opts })) {
      void run(action, body);
    }
  };
  const push = () =>
    confirmRun(
      git.upstream
        ? {
            title: t("gitBar.push"),
            message: t("gitBar.pushConfirm", {
              count: git.ahead ?? 0,
              branch: git.branch,
              upstream: git.upstream,
            }),
          }
        : {
            title: t("gitBar.publishBranch"),
            message: t("gitBar.publishBranchConfirm", { branch: git.branch }),
          },
      "push"
    );
  const publish = () =>
    confirmRun(
      {
        title: t("gitBar.publishApply"),
        message: t("gitBar.publishConfirm", { branch: git.branch, url: url.trim() }),
      },
      "publish",
      { url: url.trim() }
    );

  const merge = async (branch: string) => {
    const ok = await confirmDialog({
      title: t("gitBar.merge"),
      message: t("gitBar.mergeConfirm", { branch, current: git.branch }),
      confirmLabel: t("gitBar.merge"),
      destructive: false,
    });
    if (ok) void run("merge", { branch });
  };

  const heldBy = new Map(
    worktrees.filter((w) => w.branch).map((w) => [w.branch as string, w.path])
  );

  return (
    <div data-testid="lane-git-bar" className="space-y-1">
      <div className="flex min-w-0 flex-wrap items-center gap-x-2 gap-y-1">
        {lead}
        {/* Ahead/behind first: it is the fact that decides which of the
            buttons beside it the user actually wants. */}
        {/* Null counts with an upstream named means git could not compare
            the two (the upstream ref is gone): claiming "in sync" there
            would be a lie, so it reads as not pushed. */}
        {git.unborn ? (
          <span className="shrink-0 font-mono text-[11px] text-fg-muted">
            {t("gitBar.noCommits")}
          </span>
        ) : git.upstream && git.ahead != null && git.behind != null ? (
          <span
            data-testid="lane-git-tracking"
            title={git.upstream}
            className="flex shrink-0 items-center gap-1 font-mono text-[11px] text-fg-muted"
          >
            {(git.ahead ?? 0) > 0 && (
              <span className="flex items-center text-status-warning">
                <ArrowUp className="h-3 w-3" />
                {git.ahead}
              </span>
            )}
            {(git.behind ?? 0) > 0 && (
              <span className="flex items-center text-accent">
                <ArrowDown className="h-3 w-3" />
                {git.behind}
              </span>
            )}
            {!git.ahead && !git.behind && <span>{t("gitBar.inSync")}</span>}
          </span>
        ) : (
          git.hasRemote && (
            <span className="shrink-0 font-mono text-[11px] text-fg-muted">
              {t("gitBar.noUpstream")}
            </span>
          )
        )}

        {/* Diverged: a --ff-only pull can only refuse, so offer the merge. */}
        {git.upstream && (git.ahead ?? 0) > 0 && (git.behind ?? 0) > 0 && !merging && (
          <Btn
            label={t("gitBar.mergeUpstream", { upstream: git.upstream })}
            icon={<GitMerge className="h-3 w-3" />}
            busy={busy === "merge"}
            disabled={!!busy || dirty > 0}
            title={dirty > 0 ? t("gitBar.switchDirty") : t("gitBar.mergeUpstreamHint")}
            onClick={() => void merge(git.upstream as string)}
          />
        )}

        {/* A repo with no commit has nothing to push, fetch into or branch
            from — the one next step is the commit box below. */}
        {git.unborn ? (
          <span className="ml-auto text-[10px] text-fg-muted">{t("gitBar.unbornHint")}</span>
        ) : (
          <div className="ml-auto flex shrink-0 items-center">
            <Btn
              compact
              label={t("gitBar.fetch")}
              icon={<RefreshCw className="h-3.5 w-3.5" />}
              busy={busy === "fetch"}
              disabled={!git.hasRemote || !!busy}
              title={t("gitBar.fetchHint")}
              onClick={() => run("fetch")}
            />
            <Btn
              compact
              label={t("gitBar.pull")}
              icon={<ArrowDown className="h-3.5 w-3.5" />}
              busy={busy === "pull"}
              disabled={!git.hasRemote || !!busy || merging}
              title={
                merging
                  ? t("gitBar.merging", { op: git.operation ?? "merge" })
                  : t("gitBar.pullHint")
              }
              onClick={() => run("pull")}
            />
            <Btn
              compact
              // Same `push -u <remote> HEAD` either way; a branch with no
              // upstream is being published, not updated, so it says that.
              label={git.hasRemote && !git.upstream ? t("gitBar.publishBranch") : t("gitBar.push")}
              icon={<Upload className="h-3.5 w-3.5" />}
              busy={busy === "push"}
              disabled={!git.hasRemote || !!busy}
              title={
                git.hasRemote && !git.upstream
                  ? t("gitBar.publishBranchHint")
                  : t("gitBar.pushHint")
              }
              onClick={() => void push()}
            />
            {!git.hasRemote && (
              <Btn
                compact
                label={t("gitBar.publish")}
                icon={<CloudUpload className="h-3.5 w-3.5" />}
                disabled={!!busy}
                title={t("gitBar.publishHint")}
                onClick={() => {
                  setPublishing((v) => !v);
                  setError(null);
                }}
              />
            )}
            <Btn
              compact
              label={t("gitBar.switch")}
              icon={<GitBranch className="h-3.5 w-3.5" />}
              disabled={!!busy || merging}
              // A dirty tree is refused server-side; saying so before the click
              // beats a red box after it.
              title={
                merging
                  ? t("gitBar.merging", { op: git.operation ?? "merge" })
                  : dirty > 0
                    ? t("gitBar.switchDirty")
                    : t("gitBar.switchHint")
              }
              onClick={openSwitch}
            />
          </div>
        )}
      </div>

      {switching && (
        <div className="flex flex-wrap items-center gap-1.5">
          <select
            aria-label={t("gitBar.switchLabel")}
            value={picked}
            disabled={!!busy}
            onChange={(e) => setPicked(e.target.value)}
            className="select min-w-[8rem] flex-1 !rounded !py-0.5 !pl-2 !pr-6 font-mono !text-[11px]"
          >
            <option value="">{t("gitBar.switchLabel")}</option>
            {(branches || []).map((b) => {
              const held = heldBy.get(b);
              return (
                <option key={b} value={b}>
                  {b}
                  {b === git.branch ? ` — ${t("gitBar.switchCurrent")}` : held ? ` — ${held}` : ""}
                </option>
              );
            })}
          </select>
          <Btn
            label={t("gitBar.switchApply")}
            busy={busy === "switch"}
            // A branch git already has checked out somewhere else cannot be
            // switched to — git allows one worktree per branch.
            disabled={!picked || picked === git.branch || !!heldBy.get(picked) || dirty > 0}
            title={dirty > 0 ? t("gitBar.switchDirty") : t("gitBar.switchHint")}
            onClick={() => void run("switch", { branch: picked })}
          />
          <Btn
            label={t("gitBar.merge")}
            icon={<GitMerge className="h-3 w-3" />}
            busy={busy === "merge"}
            disabled={!picked || picked === git.branch || dirty > 0 || !!busy}
            title={dirty > 0 ? t("gitBar.switchDirty") : t("gitBar.mergeHint")}
            onClick={() => void merge(picked)}
          />
          {onNewLane && (
            <Btn
              label={t("gitBar.newLane")}
              // A branch any worktree holds — this lane's own included — is
              // one `addWorktree` refuses with EBRANCHBUSY; say so up front.
              title={
                picked && (heldBy.has(picked) || picked === git.branch)
                  ? t("gitBar.newLaneHeld", {
                      path: heldBy.get(picked) ?? t("gitBar.switchCurrent"),
                    })
                  : t("gitBar.newLaneHint")
              }
              disabled={!picked || heldBy.has(picked) || picked === git.branch}
              // The sibling lane is created through the normal Add-lane flow,
              // prefilled — one provisioning path, not a second one here.
              onClick={() => onNewLane(picked)}
            />
          )}
          <Btn
            label={t("gitBar.branchDelete")}
            icon={<Trash2 className="h-3 w-3" />}
            busy={busy === "branch-delete"}
            disabled={!picked || picked === git.branch || !!heldBy.get(picked)}
            title={t("gitBar.branchDeleteHint")}
            onClick={() =>
              void confirmRun(
                {
                  title: t("gitBar.branchDelete"),
                  message: t("gitBar.branchDeleteConfirm", { branch: picked }),
                  destructive: true,
                },
                "branch-delete",
                { branch: picked }
              )
            }
          />
          {dirty > 0 && (
            <span className="text-[10px] text-status-warning">{t("gitBar.switchDirty")}</span>
          )}
        </div>
      )}

      {switching && (
        <div className="flex items-center gap-1.5">
          <input
            value={newBranch}
            onChange={(e) => setNewBranch(e.target.value)}
            onKeyDown={(e) => {
              if (isSubmitEnter(e) && newBranch.trim())
                void run("branch-create", { branch: newBranch.trim() });
            }}
            placeholder={t("gitBar.branchNewPlaceholder")}
            aria-label={t("gitBar.branchNewPlaceholder")}
            className="min-w-0 flex-1 rounded border border-border-light bg-surface-0 px-2 py-0.5 font-mono text-[11px] text-fg-primary placeholder:text-fg-muted focus:border-accent focus:outline-none"
          />
          <Btn
            label={t("gitBar.branchCreate")}
            icon={<Plus className="h-3 w-3" />}
            busy={busy === "branch-create"}
            disabled={!newBranch.trim()}
            // Creating does not switch: the point is usually a sibling lane,
            // and moving this pane's HEAD under a working agent is not.
            title={t("gitBar.branchCreateHint")}
            onClick={() => void run("branch-create", { branch: newBranch.trim() })}
          />
        </div>
      )}

      {publishing && !git.hasRemote && !git.unborn && (
        <div className="flex items-center gap-1.5">
          <input
            value={url}
            onChange={(e) => setUrl(e.target.value)}
            onKeyDown={(e) => {
              if (isSubmitEnter(e) && url.trim()) void publish();
            }}
            // The server decides which URLs are acceptable (https without a
            // token, ssh, user@host:path); this only names the two usual ones.
            placeholder={t("gitBar.publishUrl")}
            aria-label={t("gitBar.publishUrl")}
            className="min-w-0 flex-1 rounded border border-border-light bg-surface-0 px-2 py-0.5 font-mono text-[11px] text-fg-primary placeholder:text-fg-muted focus:border-accent focus:outline-none"
          />
          <Btn
            label={t("gitBar.publishApply")}
            icon={<Upload className="h-3 w-3" />}
            busy={busy === "publish"}
            disabled={!url.trim()}
            title={t("gitBar.publishHint")}
            onClick={() => void publish()}
          />
        </div>
      )}

      {login && (
        <form
          data-testid="lane-git-login"
          className="space-y-1.5 rounded border border-border-light bg-surface-1 p-2 text-[11px]"
          onSubmit={(e) => {
            e.preventDefault();
            const { protocol, host } = login.auth;
            void run(login.action, {
              credentials: { protocol, host, username: username.trim(), password, remember },
            });
          }}
        >
          <p className="font-medium text-fg-primary">
            {t("gitBar.loginTitle", { host: login.auth.host })}
          </p>
          {login.auth.rejected && (
            <p role="alert" className="text-status-danger">
              {t("gitBar.loginRejected")}
            </p>
          )}
          <div className="flex gap-1.5">
            <input
              aria-label={t("gitBar.loginUser")}
              placeholder={t("gitBar.loginUser")}
              autoComplete="username"
              value={username}
              onChange={(e) => setUsername(e.target.value)}
              className="min-w-0 flex-1 rounded border border-border-light bg-surface-0 px-2 py-0.5 text-fg-primary placeholder:text-fg-muted focus:border-accent focus:outline-none"
            />
            <input
              type="password"
              aria-label={t("gitBar.loginPassword")}
              placeholder={t("gitBar.loginPassword")}
              autoComplete="current-password"
              value={password}
              onChange={(e) => setPassword(e.target.value)}
              className="min-w-0 flex-1 rounded border border-border-light bg-surface-0 px-2 py-0.5 text-fg-primary placeholder:text-fg-muted focus:border-accent focus:outline-none"
            />
          </div>
          <Checkbox checked={remember} onChange={setRemember} label={t("gitBar.loginRemember")} />
          <p className="text-[10px] text-fg-muted">{t("gitBar.loginTokenHint")}</p>
          {/* The token crosses the network in the clear on a plain-http LAN address. */}
          {location.protocol === "http:" && !LOCAL_HOST.test(location.hostname) && (
            <p className="text-[10px] text-status-warning">{t("gitBar.loginInsecure")}</p>
          )}
          <div className="flex gap-1.5">
            <button
              type="submit"
              disabled={!username.trim() || !password || !!busy}
              className="rounded border border-accent/40 bg-accent/15 px-2 py-0.5 text-accent hover:bg-accent/25 disabled:cursor-not-allowed disabled:opacity-40"
            >
              {t("gitBar.loginSubmit")}
            </button>
            <Btn
              label={t("gitBar.loginCancel")}
              onClick={() => {
                setLogin(null);
                setPassword("");
              }}
            />
          </div>
        </form>
      )}

      {error && (
        <pre
          role="alert"
          data-testid="lane-git-bar-error"
          className="max-h-24 overflow-auto whitespace-pre-wrap rounded border border-status-danger/40 bg-status-danger/10 px-2 py-1 text-[10px] text-status-danger"
        >
          {error}
        </pre>
      )}
    </div>
  );
}

export default LaneGitBar;