import { useEffect, useRef, useState, useCallback } from 'react';
import { useNavigate, useParams, Link } from 'react-router-dom';
import { useTranslation } from 'react-i18next';
import { usePageTitle } from '../../hooks/usePageTitle';
import { runs, runFiles } from '../../api';
import type {
  Scenario,
  ScenarioRunDetail,
  ScenarioRunStep,
  ScenarioRunLog,
  ScenarioRunStatus,
  RunStepStatus,
  LogLevel,
  FileMetadata,
} from '../../api';
import { scenarios } from '../../api';
import {
  AutoRefreshIndicator,
  Badge,
  Breadcrumbs,
  Card,
  CodeBlock,
  DescriptionList,
  Pagination,
  Search,
  Table,
  Timestamp,
  UuidBadge,
  type TableColumn,
} from '../../ui';
import type { BadgeVariant } from '../../ui';
import { ChevronDown, ChevronRight, ClipboardList, Activity } from 'lucide-react';
import styles from '../Page.module.css';

const RUN_STATUS_VARIANT: Record<ScenarioRunStatus, BadgeVariant> = {
  pending: 'neutral',
  in_progress: 'info',
  pass: 'success',
  fail: 'error',
};

const RUN_STATUS_LABEL: Record<ScenarioRunStatus, string> = {
  pending: 'Pending',
  in_progress: 'Running',
  pass: 'Pass',
  fail: 'Fail',
};

const STEP_STATUS_VARIANT: Record<RunStepStatus, BadgeVariant> = {
  waiting: 'neutral',
  pending: 'neutral',
  in_progress: 'info',
  pass: 'success',
  fail: 'error',
  cancelled: 'warning',
};

const LOG_LEVEL_VARIANT: Record<LogLevel, BadgeVariant> = {
  log: 'neutral',
  warn: 'warning',
  error: 'error',
};

const FINAL: ScenarioRunStatus[] = ['pass', 'fail'];

export function RunDetailPage() {
  const { t } = useTranslation();
  const { id, runId } = useParams<{ id: string; runId: string }>();
  const navigate = useNavigate();

  const [scenario, setScenario] = useState<Scenario | null>(null);
  const [run, setRun] = useState<ScenarioRunDetail | null>(null);
  const [loading, setLoading] = useState(true);
  usePageTitle(scenario ? `${t('runs.title')} — ${scenario.name}` : t('runs.title'));
  const [error, setError] = useState<string | null>(null);
  const [polling, setPolling] = useState(false);
  const [pulseKey, setPulseKey] = useState(0);
  const [logPage, setLogPage] = useState(1);
  const [logSearch, setLogSearch] = useState('');
  const [debouncedSearch, setDebouncedSearch] = useState('');
  const [expandAll, setExpandAll] = useState(false);
  const [expandedStepIds, setExpandedStepIds] = useState<Set<string>>(new Set());
  const [artifacts, setArtifacts] = useState<FileMetadata[]>([]);
  const [artifactsTotal, setArtifactsTotal] = useState(0);
  const [artifactsLoading, setArtifactsLoading] = useState(false);
  const logSearchRef = useRef('');
  const LOG_PAGE_SIZE = 25;
  const pollRef = useRef<ReturnType<typeof setInterval> | null>(null);

  const stopPolling = () => {
    if (pollRef.current) {
      clearInterval(pollRef.current);
      pollRef.current = null;
      setPolling(false);
    }
  };

  const manualRefresh = () => {
    if (!id || !runId) return;
    runs
      .get(id, runId, logSearchRef.current)
      .then((r) => {
        setRun(r);
        setError(null);
        setPulseKey((k) => k + 1);
      })
      .catch((err: Error) => setError(err.message));
  };

  const loadArtifacts = useCallback(async () => {
    if (!id || !runId) return;
    setArtifactsLoading(true);
    try {
      const result = await runFiles.list(id, runId);
      setArtifacts(result.items);
      setArtifactsTotal(result.total);
    } catch {
      // Silently fail - artifacts are not critical
      setArtifacts([]);
      setArtifactsTotal(0);
    } finally {
      setArtifactsLoading(false);
    }
  }, [id, runId]);

  useEffect(() => {
    const t = setTimeout(() => {
      setDebouncedSearch(logSearch);
      logSearchRef.current = logSearch;
      setLogPage(1);
    }, 300);
    return () => clearTimeout(t);
  }, [logSearch]);

  useEffect(() => {
    if (!id || !runId || polling) return;
    runs
      .get(id, runId, debouncedSearch)
      .then(setRun)
      .catch(() => undefined);
  }, [id, runId, polling, debouncedSearch]);

  useEffect(() => {
    if (!id || !runId) return;
    let cancelled = false;

    Promise.all([scenarios.get(id), runs.get(id, runId)])
      .then(([sc, r]) => {
        if (cancelled) return;
        setScenario(sc);
        setRun(r);
        loadArtifacts();
        if (!FINAL.includes(r.status)) {
          setPolling(true);
          pollRef.current = setInterval(async () => {
            try {
              const updated = await runs.get(id, runId, logSearchRef.current);
              if (cancelled) return;
              setRun(updated);
              setPulseKey((k) => k + 1);
              if (FINAL.includes(updated.status)) {
                stopPolling();
                await loadArtifacts();
              }
            } catch {
              stopPolling();
            }
          }, 1000);
        }
      })
      .catch((err: Error) => {
        if (!cancelled) setError(err.message);
      })
      .finally(() => {
        if (!cancelled) setLoading(false);
      });

    return () => {
      cancelled = true;
      stopPolling();
    };
  }, [id, runId, loadArtifacts]);

  const stepColumns: TableColumn<ScenarioRunStep>[] = [
    { key: 'order', header: t('runs.step_order'), render: (s) => s.order, width: 50 },
    {
      key: 'title',
      header: t('runs.step_title'),
      width: 220,
      render: (s) => s.scenarioStep?.title ?? <span className={styles.muted}>–</span>,
    },
    {
      key: 'status',
      header: t('runs.step_status'),
      width: 110,
      render: (s) => (
        <Badge variant={STEP_STATUS_VARIANT[s.status]}>{s.status.replace('_', ' ')}</Badge>
      ),
    },
    {
      key: 'description',
      header: (
        <div
          style={{
            display: 'flex',
            alignItems: 'center',
            justifyContent: 'space-between',
            gap: '8px',
          }}
        >
          <span>{t('runs.step_description')}</span>
          {run?.stepRuns.some((s) => s.output) && (
            <button
              onClick={() => {
                if (expandAll) {
                  setExpandAll(false);
                  setExpandedStepIds(new Set());
                } else {
                  setExpandAll(true);
                  setExpandedStepIds(
                    new Set(run?.stepRuns.filter((s) => s.output).map((s) => s.id) ?? []),
                  );
                }
              }}
              style={{
                background: 'none',
                border: 'none',
                padding: '0 4px',
                cursor: 'pointer',
                display: 'flex',
                alignItems: 'center',
                color: 'inherit',
              }}
              title={expandAll ? 'Collapse all' : 'Expand all'}
            >
              {expandAll ? <ChevronDown size={16} /> : <ChevronRight size={16} />}
            </button>
          )}
        </div>
      ),
      render: (s) => {
        const isExpanded = expandAll || expandedStepIds.has(s.id);
        return (
          <div>
            <div
              style={{
                display: 'flex',
                alignItems: 'flex-start',
                gap: '8px',
                marginBottom: isExpanded && s.output ? '8px' : 0,
              }}
            >
              {s.output && (
                <button
                  onClick={() => {
                    const newSet = new Set(expandedStepIds);
                    if (newSet.has(s.id)) {
                      newSet.delete(s.id);
                    } else {
                      newSet.add(s.id);
                    }
                    setExpandedStepIds(newSet);
                  }}
                  style={{
                    background: 'none',
                    border: 'none',
                    padding: 0,
                    cursor: 'pointer',
                    display: 'flex',
                    alignItems: 'center',
                    flexShrink: 0,
                    marginTop: '2px',
                  }}
                >
                  {isExpanded ? <ChevronDown size={16} /> : <ChevronRight size={16} />}
                </button>
              )}
              <code style={{ wordBreak: 'break-word' }}>
                {s.description ? (
                  s.description
                ) : s.output ? (
                  <span title={`${s.output.length} bytes`}>{s.output.length} bytes</span>
                ) : (
                  <span className={styles.muted}>–</span>
                )}
              </code>
            </div>
            {isExpanded && s.output && (
              <div style={{ marginLeft: '24px' }}>
                <CodeBlock
                  code={(() => {
                    try {
                      return JSON.stringify(JSON.parse(s.output), null, 2);
                    } catch {
                      return s.output;
                    }
                  })()}
                  language="json"
                />
              </div>
            )}
          </div>
        );
      },
    },
  ];

  const logColumns: TableColumn<ScenarioRunLog>[] = [
    {
      key: 'level',
      header: t('runs.log_level'),
      width: 70,
      render: (l) => <Badge variant={LOG_LEVEL_VARIANT[l.level]}>{l.level}</Badge>,
    },
    {
      key: 'message',
      header: t('runs.log_message'),
      render: (l) => <code style={{ wordBreak: 'break-word' }}>{l.message}</code>,
    },
    {
      key: 'time',
      header: t('runs.log_time'),
      width: 160,
      render: (l) => <Timestamp value={l.createdAt} />,
    },
  ];

  return (
    <div>
      <div className={styles.pageToolbar}>
        <Breadcrumbs
          items={[
            {
              label: t('scenarios.title'),
              icon: <ClipboardList size={14} />,
              onClick: () => navigate('/scenarios'),
            },
            {
              label: scenario?.name ?? `${id}`,
              onClick: () => navigate(`/scenarios/${id}`),
            },
            {
              label: t('runs.title'),
              icon: <Activity size={14} />,
              onClick: () => navigate(`/scenarios/${id}/runs`),
            },
            { label: `${runId}` },
          ]}
        />
        <AutoRefreshIndicator
          active={polling}
          pulseKey={pulseKey}
          error={!!error}
          onClick={manualRefresh}
        />
      </div>

      {loading && <p className={styles.muted}>{t('runs.loading')}</p>}

      {run && (
        <>
          <Card>
            <DescriptionList
              layout="grid"
              items={(() => {
                const items = [
                  { term: t('runs.field_id'), detail: <UuidBadge id={run.id} /> },
                  {
                    term: t('runs.field_status'),
                    detail: (
                      <Badge variant={RUN_STATUS_VARIANT[run.status]}>
                        {RUN_STATUS_LABEL[run.status]}
                      </Badge>
                    ),
                  },
                  { term: t('runs.field_created'), detail: <Timestamp value={run.createdAt} /> },
                  { term: t('runs.field_updated'), detail: <Timestamp value={run.updatedAt} /> },
                ];
                if (run.environment) {
                  items.push({
                    term: 'Environment',
                    detail: (
                      <Link
                        to={`/environments/${run.environment.id}`}
                        style={{ color: 'var(--color-link)' }}
                      >
                        {run.environment.name}
                      </Link>
                    ),
                  });
                }
                if (run.session) {
                  items.push({
                    term: 'Session',
                    detail: (
                      <Link
                        to={`/sessions/${run.session.id}`}
                        style={{ color: 'var(--color-link)' }}
                      >
                        {run.session.sessionName}
                      </Link>
                    ),
                  });
                }
                return items;
              })()}
            />
          </Card>

          {run.stepRuns.length > 0 && (
            <div className={styles.stepsSection}>
              <h2 className={styles.sectionHeading}>{t('runs.steps_heading')}</h2>
              <Table
                columns={stepColumns}
                data={run.stepRuns}
                rowKey={(s) => s.id}
                loading={false}
                emptyMessage=""
              />
            </div>
          )}

          {run.logs.length > 0 && (
            <div className={styles.stepsSection}>
              <div className={styles.sectionHeadingRow}>
                <h2 className={styles.sectionHeading}>{t('runs.logs_heading')}</h2>
                <Search
                  value={logSearch}
                  onChange={setLogSearch}
                  placeholder={t('runs.logs_search_placeholder')}
                />
              </div>
              <Table
                columns={logColumns}
                data={run.logs.slice((logPage - 1) * LOG_PAGE_SIZE, logPage * LOG_PAGE_SIZE)}
                rowKey={(l) => l.id}
                loading={false}
                emptyMessage=""
              />
              {run.logs.length > LOG_PAGE_SIZE && (
                <Pagination
                  page={logPage}
                  pageSize={LOG_PAGE_SIZE}
                  total={run.logs.length}
                  onPageChange={setLogPage}
                />
              )}
            </div>
          )}

          {(artifactsTotal > 0 || artifactsLoading) && (
            <div className={styles.stepsSection}>
              <h2 className={styles.sectionHeading}>{t('files.artifactsTitle')}</h2>
              <Table<FileMetadata>
                loading={artifactsLoading}
                data={artifacts}
                rowKey={(f) => f.id}
                columns={
                  [
                    { key: 'name', header: t('files.name'), render: (f) => f.name },
                    {
                      key: 'mimeType',
                      header: t('files.mimeType'),
                      render: (f) => f.mimeType,
                    },
                    {
                      key: 'size',
                      header: t('files.size'),
                      render: (f) => `${(f.size / 1024).toFixed(1)} KB`,
                    },
                    {
                      key: 'expiresAt',
                      header: t('files.expiresAt'),
                      render: (f) => (f.expiresAt ? <Timestamp value={f.expiresAt} /> : '—'),
                    },
                    {
                      key: 'createdAt',
                      header: t('files.createdAt'),
                      render: (f) => <Timestamp value={f.createdAt} />,
                    },
                    {
                      key: 'download',
                      header: '',
                      render: (f) => (
                        <a href={runFiles.contentUrl(id!, runId!, f.id)} download={f.name}>
                          {t('files.download')}
                        </a>
                      ),
                    },
                  ] satisfies TableColumn<FileMetadata>[]
                }
                emptyMessage={t('files.empty')}
              />
            </div>
          )}
        </>
      )}
    </div>
  );
}