import { useState } from "react";
import { Link, Navigate, useNavigate, useSearchParams } from "react-router-dom";
import { LuActivity, LuCopy, LuPencil, LuPlay, LuPlus, LuRefreshCw, LuTrash2, LuTriangleAlert } from "react-icons/lu";
import { errorMessage } from "../api/client.js";
import {
  useDeleteWorkflow,
  useReregisterWorkflows,
  useRunWorkflow,
  useSetWorkflowEnabled,
  useWorkflows,
} from "../api/hooks.js";
import { DuplicateWorkflowDialog } from "../components/DuplicateWorkflowDialog.jsx";
import { ConfirmDialog } from "../components/ConfirmDialog.jsx";
import { WorkflowFileIcon } from "../components/WorkflowFileIcon.jsx";
import { formatTime, WorkflowStatusBadge } from "../lib/format";

const SORT_COLUMNS = [
  { key: "name", label: "Name", defaultOrder: "asc" },
  { key: "status", label: "Status", defaultOrder: "asc" },
  { key: "lastModifiedAt", label: "Last modified", defaultOrder: "desc" },
  { key: "lastInvokedAt", label: "Last run", defaultOrder: "desc" },
  { key: "invocationCount", label: "Runs", defaultOrder: "desc" },
];

function SortHeader({ column, label, sort, order, onSort }) {
  const active = sort === column;
  return (
    <th>
      <button
        type="button"
        className={`font-semibold hover:underline ${active ? "" : "opacity-80"}`}
        onClick={() => onSort(column)}
      >
        {label}
        {active ? (order === "asc" ? " ↑" : " ↓") : ""}
      </button>
    </th>
  );
}

function statusSortKey(w) {
  if (w.loadError) return "0-broken";
  if (!w.enabled) return "1-disabled";
  if (w.lastStatus === "failed") return "2-failed";
  if (w.lastStatus === "queued") return "3-queued";
  if (w.lastStatus === "running") return "4-running";
  if (w.lastStatus === "success") return "5-working";
  return "6-never";
}

function compareName(a, b) {
  const byName = String(a.name ?? "").localeCompare(String(b.name ?? ""), undefined, {
    sensitivity: "base",
  });
  if (byName !== 0) return byName;
  return String(a.key ?? "").localeCompare(String(b.key ?? ""));
}

function compareWorkflows(a, b, sort) {
  if (sort === "name") return compareName(a, b);
  if (sort === "status") {
    const byStatus = statusSortKey(a).localeCompare(statusSortKey(b));
    return byStatus !== 0 ? byStatus : compareName(a, b);
  }
  if (sort === "invocationCount") {
    const byCount = (Number(a.invocationCount) || 0) - (Number(b.invocationCount) || 0);
    return byCount !== 0 ? byCount : compareName(a, b);
  }
  const aTime = a[sort] ?? "";
  const bTime = b[sort] ?? "";
  const byTime = String(aTime).localeCompare(String(bTime));
  return byTime !== 0 ? byTime : compareName(a, b);
}

export function WorkflowsPage() {
  const navigate = useNavigate();
  const [params] = useSearchParams();
  const editParam = params.get("edit");
  const { data: workflows = [], isLoading } = useWorkflows();
  const [sort, setSortColumn] = useState("name");
  const [order, setOrder] = useState("asc");
  const [confirmDelete, setConfirmDelete] = useState(null);
  const [duplicateSource, setDuplicateSource] = useState(null);
  const [runError, setRunError] = useState(null);
  const del = useDeleteWorkflow();
  const run = useRunWorkflow();
  const setEnabled = useSetWorkflowEnabled();
  const reregister = useReregisterWorkflows();

  if (editParam) {
    const slash = editParam.indexOf("/");
    if (slash !== -1) {
      const owner = editParam.slice(0, slash);
      const file = editParam.slice(slash + 1);
      return (
        <Navigate
          to={`/workflows/${encodeURIComponent(owner)}/${encodeURIComponent(file)}/edit`}
          replace
        />
      );
    }
  }

  function onRun(w) {
    setRunError(null);
    run.mutate(
      { owner: w.owner, file: w.file },
      {
        onSuccess: (data) => {
          if (data?.runId) navigate(`/events/${data.runId}`);
        },
        onError: (err) => {
          const runId = err?.response?.data?.runId;
          if (runId) {
            navigate(`/events/${runId}`);
            return;
          }
          setRunError(`${w.key}: ${errorMessage(err)}`);
        },
      },
    );
  }

  const runningKey =
    run.isPending && run.variables ? `${run.variables.owner}/${run.variables.file}` : null;
  const togglingKey =
    setEnabled.isPending && setEnabled.variables
      ? `${setEnabled.variables.owner}/${setEnabled.variables.file}`
      : null;

  const dir = order === "desc" ? -1 : 1;
  const sortedWorkflows = [...workflows].sort((a, b) => dir * compareWorkflows(a, b, sort));

  function setSort(column) {
    const spec = SORT_COLUMNS.find((c) => c.key === column);
    if (sort === column) {
      setOrder((prev) => (prev === "asc" ? "desc" : "asc"));
      return;
    }
    setSortColumn(column);
    setOrder(spec?.defaultOrder ?? "asc");
  }

  return (
    <div className="space-y-4">
      <div className="flex items-center justify-between gap-2">
        <h1 className="text-xl font-semibold">Workflows</h1>
        <div className="flex items-center gap-2">
          <Link to="/workflows/trash" className="btn btn-ghost btn-sm">
            <LuTrash2 className="size-4" />
            Trash
          </Link>
          <button
            type="button"
            className="btn btn-ghost btn-sm"
            title="Reregister workflows"
            aria-label="Reregister workflows"
            disabled={reregister.isPending}
            onClick={() => reregister.mutate()}
          >
            {reregister.isPending ? (
              <span className="loading loading-spinner loading-xs" />
            ) : (
              <LuRefreshCw className="size-4" />
            )}
            Reregister
          </button>
          <Link to="/workflows/new" className="btn btn-primary btn-sm">
            <LuPlus className="size-4" />
            Add
          </Link>
        </div>
      </div>

      {reregister.isError ? (
        <p className="text-error text-sm">{errorMessage(reregister.error)}</p>
      ) : null}

      {runError ? <p className="text-error text-sm">{runError}</p> : null}
      {setEnabled.isError ? (
        <p className="text-error text-sm">{errorMessage(setEnabled.error)}</p>
      ) : null}

      {isLoading ? (
        <span className="loading loading-spinner" />
      ) : (
        <div className="overflow-x-auto">
          <table className="table table-sm">
            <thead>
              <tr>
                <SortHeader column="name" label="Name" sort={sort} order={order} onSort={setSort} />
                <SortHeader column="status" label="Status" sort={sort} order={order} onSort={setSort} />
                <th>Triggers</th>
                <SortHeader
                  column="lastModifiedAt"
                  label="Last modified"
                  sort={sort}
                  order={order}
                  onSort={setSort}
                />
                <SortHeader
                  column="lastInvokedAt"
                  label="Last run"
                  sort={sort}
                  order={order}
                  onSort={setSort}
                />
                <SortHeader
                  column="invocationCount"
                  label="Runs"
                  sort={sort}
                  order={order}
                  onSort={setSort}
                />
                <th />
              </tr>
            </thead>
            <tbody>
              {sortedWorkflows.map((w) => (
                <tr key={w.key} className="hover">
                  <td>
                    <Link
                      className="link inline-flex items-center gap-2"
                      to={`/workflows/${encodeURIComponent(w.owner)}/${encodeURIComponent(w.file)}/edit`}
                    >
                      <WorkflowFileIcon className="size-7 shrink-0" />
                      {w.name}
                      <span className="block font-mono text-xs opacity-50">{w.file}</span>
                    </Link>
                    {!w.registered ? (
                      <span
                        className="text-warning ml-1 inline-flex align-middle"
                        title="Not listed in registers.yaml"
                      >
                        <LuTriangleAlert className="size-3.5" />
                      </span>
                    ) : null}
                  </td>
                  <td>
                    <WorkflowStatusBadge workflow={w} />
                  </td>
                  <td>
                    <TriggerList triggers={w.triggers} />
                  </td>
                  <td className="whitespace-nowrap">{formatTime(w.lastModifiedAt)}</td>
                  <td className="whitespace-nowrap">{formatTime(w.lastInvokedAt)}</td>
                  <td>{w.invocationCount}</td>
                  <td className="text-right whitespace-nowrap">
                    <label
                      className="inline-flex items-center mr-1"
                      title={w.enabled ? "Disable" : "Enable"}
                      aria-label={w.enabled ? "Disable" : "Enable"}
                    >
                      <input
                        type="checkbox"
                        className="toggle toggle-success toggle-xs"
                        checked={Boolean(w.enabled)}
                        disabled={Boolean(w.loadError) || togglingKey === w.key}
                        onChange={() =>
                          setEnabled.mutate({
                            owner: w.owner,
                            file: w.file,
                            enabled: !w.enabled,
                          })
                        }
                      />
                    </label>
                    <button
                      type="button"
                      className="btn btn-ghost btn-xs"
                      title="Run"
                      aria-label="Run"
                      disabled={Boolean(w.loadError) || runningKey === w.key}
                      onClick={() => onRun(w)}
                    >
                      {runningKey === w.key ? (
                        <span className="loading loading-spinner loading-xs" />
                      ) : (
                        <LuPlay className="size-4" />
                      )}
                    </button>
                    <Link
                      className="btn btn-ghost btn-xs"
                      title="Events"
                      aria-label="Events"
                      to={`/events?workflow=${encodeURIComponent(w.key)}`}
                    >
                      <LuActivity className="size-4" />
                    </Link>
                    <Link
                      className="btn btn-ghost btn-xs"
                      title="Edit"
                      aria-label="Edit"
                      to={`/workflows/${encodeURIComponent(w.owner)}/${encodeURIComponent(w.file)}/edit`}
                    >
                      <LuPencil className="size-4" />
                    </Link>
                    <button
                      type="button"
                      className="btn btn-ghost btn-xs"
                      title="Duplicate"
                      aria-label="Duplicate"
                      disabled={Boolean(w.loadError)}
                      onClick={() => setDuplicateSource(w)}
                    >
                      <LuCopy className="size-4" />
                    </button>
                    <button
                      type="button"
                      className="btn btn-ghost btn-xs text-error"
                      title="Move to trash"
                      aria-label="Move to trash"
                      onClick={() => setConfirmDelete(w)}
                    >
                      <LuTrash2 className="size-4" />
                    </button>
                  </td>
                </tr>
              ))}
            </tbody>
          </table>
        </div>
      )}

      {duplicateSource ? (
        <DuplicateWorkflowDialog
          source={duplicateSource}
          onClose={() => setDuplicateSource(null)}
          onDuplicated={(data) => {
            setDuplicateSource(null);
            navigate(
              `/workflows/${encodeURIComponent(data.owner)}/${encodeURIComponent(data.file)}/edit`,
            );
          }}
        />
      ) : null}

      <ConfirmDialog
        open={Boolean(confirmDelete)}
        title={confirmDelete ? `Move ${confirmDelete.key} to trash?` : ""}
        message="The workflow is removed from the list but kept in trash for 7 days. Revision history is preserved."
        confirmLabel="Move to trash"
        error={del.isError ? errorMessage(del.error) : null}
        loading={del.isPending}
        onCancel={() => setConfirmDelete(null)}
        onConfirm={() =>
          del.mutate(
            { owner: confirmDelete.owner, file: confirmDelete.file },
            { onSuccess: () => setConfirmDelete(null) },
          )
        }
      />
    </div>
  );
}

function triggerLabel(t) {
  const type = String(t?.type ?? "").toLowerCase();
  if (type === "cron") return t.schedule || "cron";
  if (type === "http") return t.path || "/";
  if (type === "workflow") return "";
  return t?.type ?? "—";
}

function triggerKind(t) {
  const type = String(t?.type ?? "").toLowerCase();
  if (type === "http") return t.method || "POST";
  if (type === "workflow") return "workflow";
  return t?.type ?? "—";
}

function TriggerList({ triggers }) {
  if (!triggers?.length) return <span className="opacity-50">—</span>;
  return (
    <ul className="space-y-0.5">
      {triggers.map((t, i) => (
        <li key={i} className="font-mono text-xs whitespace-nowrap">
          <span className="opacity-60">{triggerKind(t)}</span> {triggerLabel(t)}
        </li>
      ))}
    </ul>
  );
}