import React, { useCallback, useEffect, useId, useMemo, useRef, useState } from "react";
import {
  BlockerFunction, useBeforeUnload, useBlocker, useLocation, useNavigate, useParams, useSearchParams,
} from "react-router-dom";

import {
  Accordion, AccordionDetails, AccordionSummary, Alert, Box, Button, Chip, IconButton, Paper,
  Skeleton, Stack, Tab, Tabs, Tooltip, Typography,
} from "@mui/material";
import ArrowBackIcon from "@mui/icons-material/ArrowBack";
import ArrowForwardIcon from "@mui/icons-material/ArrowForward";
import OpenInNewIcon from "@mui/icons-material/OpenInNew";
import DescriptionOutlinedIcon from "@mui/icons-material/DescriptionOutlined";
import MailOutlineIcon from "@mui/icons-material/MailOutline";
import FolderOutlinedIcon from "@mui/icons-material/FolderOutlined";
import AutoFixHighIcon from "@mui/icons-material/AutoFixHigh";
import ChecklistIcon from "@mui/icons-material/Checklist";
import EditOutlinedIcon from "@mui/icons-material/EditOutlined";
import ExpandMoreIcon from "@mui/icons-material/ExpandMore";

import { getApiErrorMessage } from "../api";
import Attachments from "../components/Attachments";
import Correspondence from "../components/Correspondence";
import ApplicationChecklist from "../components/ApplicationChecklist";
import ApplicationCalendarActions from "../components/ApplicationCalendarActions";
import {
  ApplicationAnalysis, ApplicationMatch, ApplicationTimeline,
} from "../components/ApplicationIntelligence";
import {
  ApplicationCoverLetterSection, ApplicationCvSection, ApplicationPackageDraftsSection, SubmittedPackagesSection,
} from "../components/ApplicationAssets";
import { ApplicationInterviewPrep } from "../components/InterviewPrep";
import EditJobDialog from "../components/EditJobDialog";
import ViewStateNotice from "../components/ViewStateNotice";
import { PageHeader, PageSection } from "../layout/PageLayout";
import type { ViewResourceError } from "../hooks/useViewResource";
import { ApplicationStatusSuggestion, ApplicationStrategySnapshot } from "../components/ApplicationWorkflowAssist";
import { PIPELINE_STATUSES, normalizeStatus, statusLabel, statusTone } from "../pipeline";
import { useI18n } from "../i18n/I18nProvider";
import { useConfirm } from "../confirm";
import {
  WORKSPACE_SECTIONS, WorkspaceOverview, WorkspaceSectionKey, applicationWorkspaceApi,
  checklistSystemTranslationToken, workspaceSection, workspaceSubsection,
} from "../applicationWorkspace";

// Phase 5 Milestone 1 — the dedicated Application Workspace.
//
// This is a surface, not a new data store: the overview is one aggregate read, and each section
// reuses the component that already owns that domain (for example Attachments and Correspondence).
// docs/architecture/overview.md.
export default function ApplicationWorkspacePage() {
  return <ApplicationWorkspace />;
}

type ApplicationWorkspaceProps = {
  jobIdOverride?: number;
  sectionOverride?: WorkspaceSectionKey | "analysis" | "cv" | "cover-letter";
  onSectionChange?: (section: WorkspaceSectionKey) => void;
  onClose?: () => void;
  fullPageHref?: string;
};

export function ApplicationWorkspace({
  jobIdOverride,
  sectionOverride,
  onSectionChange,
  onClose,
  fullPageHref,
}: ApplicationWorkspaceProps) {
  const { id } = useParams();
  const jobId = jobIdOverride ?? Number(id);
  const location = useLocation();
  const navigate = useNavigate();
  const { t } = useI18n();
  const { confirm } = useConfirm();
  const [params, setParams] = useSearchParams();
  const section = workspaceSection(sectionOverride ?? params.get("section"));
  const [overlaySubsection, setOverlaySubsection] = useState<{ section: WorkspaceSectionKey; value: string } | null>(null);
  const subsection = onSectionChange && overlaySubsection?.section === section
    ? overlaySubsection.value : workspaceSubsection(sectionOverride ?? params.get("section"), params.get("sub"));
  const answersActive = section === "application" && subsection === "answers";
  const answersEntry = useMemo(() => ({ jobId, answersActive }), [jobId, answersActive]);
  const [readyAnswersEntry, setReadyAnswersEntry] = useState<object | null>(null);
  const sectionId = useId();
  const secondaryId = useId();
  const panelRef = useRef<HTMLDivElement>(null);

  const [loadedOverview, setOverview] = useState<WorkspaceOverview | null>(null);
  const overview = loadedOverview?.id === jobId ? loadedOverview : null;
  const overviewRequest = useRef(0);
  const overviewLoadedJob = useRef<number | null>(null);
  const [error, setError] = useState<ViewResourceError | null>(null);
  const [loading, setLoading] = useState(true);
  const [editOpen, setEditOpen] = useState(false);
  const [coverLetterDirty, setCoverLetterDirty] = useState(false);
  const [packageDraftsDirty, setPackageDraftsDirty] = useState(false);
  const hasUnsavedChanges = coverLetterDirty || packageDraftsDirty;

  const shouldBlock = useCallback<BlockerFunction>(
    ({ currentLocation, nextLocation }) => hasUnsavedChanges && (
      currentLocation.pathname !== nextLocation.pathname || currentLocation.search !== nextLocation.search
    ),
    [hasUnsavedChanges],
  );
  const blocker = useBlocker(shouldBlock);

  useBeforeUnload(useCallback((event) => {
    if (!hasUnsavedChanges) return;
    event.preventDefault();
    event.returnValue = "";
  }, [hasUnsavedChanges]));

  useEffect(() => {
    if (blocker.state !== "blocked") return;
    const blockedNavigation = blocker;
    let active = true;
    void confirm({
      title: t("workspaceUnsavedTitle"),
      message: t("workspaceUnsavedMessage"),
      confirmLabel: t("workspaceDiscardLeave"),
      cancelLabel: t("workspaceKeepEditing"),
      destructive: true,
    }).then((approved) => {
      if (!active) return;
      if (approved) blockedNavigation.proceed();
      else blockedNavigation.reset();
    });
    return () => { active = false; };
  }, [blocker, confirm, t]);

  const load = useCallback(async () => {
    const request = ++overviewRequest.current;
    if (!Number.isInteger(jobId) || jobId <= 0) {
      setOverview(null);
      setError({ kind: "error", message: t("workspaceInvalidLink"), retryable: false });
      setLoading(false);
      return;
    }
    try {
      setError(null);
      setLoading(true);
      const next = await applicationWorkspaceApi.overview(jobId);
      if (request === overviewRequest.current) {
        setOverview(next);
        overviewLoadedJob.current = next.id;
        setReadyAnswersEntry(answersEntry);
      }
    } catch (err) {
      if (request !== overviewRequest.current) return;
      const status = (err as { response?: { status?: number } })?.response?.status;
      setError({ kind: "error", message: getApiErrorMessage(err, t("workspaceLoadFailed")), retryable: !status || status >= 500, status });
    } finally {
      if (request === overviewRequest.current) setLoading(false);
    }
  }, [jobId, t, answersEntry]);

  const previousOverviewSource = useRef<{ jobId: number; t: typeof t; answersActive: boolean } | null>(null);
  useEffect(() => {
    const previous = previousOverviewSource.current;
    previousOverviewSource.current = { jobId, t, answersActive };
    // Each Answers entry needs a coherent source; leaving it does not need another aggregate read.
    if (answersActive || !previous?.answersActive || previous.jobId !== jobId || previous.t !== t || overviewLoadedJob.current !== jobId) void load();
    else setLoading(false);
    return () => { overviewRequest.current += 1; };
  }, [load, answersActive, jobId, t]);

  useEffect(() => {
    // Direct entry gets a named target; keyboard tab activation keeps tab focus.
    if (!loading && section !== "overview" && document.activeElement === document.body) panelRef.current?.focus({ preventScroll: true });
  }, [loading, section, subsection]);

  const go = (next: string, sub?: string) => {
    if (next === "career-profile") {
      navigate("/career?section=profile");
      return;
    }
    if (onSectionChange) {
      setOverlaySubsection({ section: workspaceSection(next), value: workspaceSubsection(next, sub ?? null) });
      onSectionChange(workspaceSection(next));
    }
    else setParams((current) => {
      const updated = new URLSearchParams(current);
      updated.set("section", next);
      if (sub) updated.set("sub", sub);
      else updated.delete("sub");
      return updated;
    }, { state: location.state });
  };
  const close = onClose ?? (() => {
    const state = location.state as { from?: unknown; focusJobId?: unknown } | null;
    const from = state?.from;
    const focusJobId = typeof state?.focusJobId === "number" ? state.focusJobId : undefined;
    navigate(
      typeof from === "string" && from.startsWith("/") && !from.startsWith("//") ? from : "/jobs",
      { replace: true, state: focusJobId ? { focusJobId } : undefined },
    );
  });
  const subsections = section === "application" ? [
    { key: "cv", label: t("workspaceCv") },
    { key: "letter", label: t("workspaceCoverLetter") },
    { key: "answers", label: t("workspaceAnswers") },
    { key: "submission", label: t("workspaceSubmission") },
  ] : [
    { key: "activity", label: t("workspaceActivityHistory") },
    { key: "correspondence", label: t("workspaceCommunication") },
  ];

  if (error) {
    return (
      <Box sx={{ display: "grid", gap: 2, minWidth: 0 }}>
        <Button startIcon={<ArrowBackIcon />} onClick={close}>{t("workspaceBack")}</Button>
        <ViewStateNotice title={t("workspaceLoadFailed")} error={error} onRetry={load} compact />
      </Box>
    );
  }

  return (
    <Box sx={{ display: "grid", gap: "var(--app-section-gap)", minWidth: 0 }}>
      <ViewStateNotice title={t("workspaceLoadFailed")} loading={loading && !overview} compact />
      <Paper variant="outlined" sx={{ minWidth: 0, borderRadius: 1 }}>
        <Stack direction="row" alignItems="center" spacing={0.5} sx={{ px: { xs: 1, sm: 2 }, pt: 1.5 }}>
          <Tooltip title={t("workspaceBack")}>
            <IconButton size="small" aria-label={t("workspaceBack")} onClick={close}>
              <ArrowBackIcon fontSize="small" />
            </IconButton>
          </Tooltip>
          <Typography variant="caption" sx={{ fontWeight: 800, letterSpacing: ".08em", textTransform: "uppercase", color: "text.secondary" }}>
            {t("workspace")}
          </Typography>
          {fullPageHref ? (
            <Tooltip title={t("workspaceOpenFull")}>
              <IconButton
                component="a"
                href={fullPageHref}
                target="_blank"
                rel="noopener noreferrer"
                size="small"
                aria-label={t("workspaceOpenFull")}
                sx={{ ml: "auto" }}
              >
                <OpenInNewIcon fontSize="small" />
              </IconButton>
            </Tooltip>
          ) : null}
        </Stack>
        <WorkspaceHeader overview={overview} onEdit={() => setEditOpen(true)} />
        <Tabs
          value={section}
          onChange={(_, value: WorkspaceSectionKey) => go(value)}
          variant="scrollable"
          scrollButtons="auto"
          aria-label={t("workspaceSections")}
          sx={{ px: { xs: 0.5, sm: 1.5 }, borderTop: 1, borderColor: "divider", minHeight: 46 }}
        >
          {WORKSPACE_SECTIONS.map((s) => <Tab key={s.key} id={`${sectionId}-${s.key}`} aria-controls={`${sectionId}-panel`} value={s.key} label={workspaceSectionLabel(t, s.key)} sx={{ minHeight: 46, fontWeight: 700 }} />)}
        </Tabs>
      </Paper>

      <Box ref={panelRef} role="tabpanel" id={`${sectionId}-panel`} aria-labelledby={`${sectionId}-${section}`} tabIndex={0} sx={{ display: "grid", gap: 2, minWidth: 0 }}>
        {section === "overview" && jobId > 0 && <ApplicationStatusSuggestion jobId={jobId} onApplied={load} />}
        {section === "overview" && <OverviewSection overview={overview} onGo={go} onReload={load} onEdit={() => setEditOpen(true)} />}
        {section === "match" && jobId > 0 && (
          <Stack spacing={2}>
            <ApplicationAnalysis jobId={jobId} />
            <ApplicationMatch jobId={jobId} />
            <ApplicationStrategySnapshot jobId={jobId} />
          </Stack>
        )}
        {section === "interview" && jobId > 0 && <ApplicationInterviewPrep jobId={jobId} />}
        {(section === "application" || section === "timeline") && <>
          <Tabs value={subsection} onChange={(_, sub: string) => go(section, sub)} variant="scrollable" scrollButtons="auto" aria-label={t(section === "application" ? "workspaceApplicationSections" : "workspaceTimelineSections")}>
            {subsections.map((sub) => <Tab key={sub.key} value={sub.key} id={`${secondaryId}-${sub.key}`} aria-controls={`${secondaryId}-panel`} label={sub.label} />)}
          </Tabs>
          <Box role="tabpanel" id={`${secondaryId}-panel`} aria-labelledby={`${secondaryId}-${subsection}`} tabIndex={0} sx={{ display: "grid", gap: 2, minWidth: 0 }}>
            {section === "application" && subsection === "cv" && jobId > 0 && <ApplicationCvSection key={jobId} jobId={jobId} includePackages={false} />}
            {section === "application" && subsection === "letter" && jobId > 0 && <ApplicationCoverLetterSection key={jobId} jobId={jobId} onDirtyChange={setCoverLetterDirty} />}
            {answersActive && readyAnswersEntry === answersEntry && overview && jobId > 0 && <ApplicationPackageDraftsSection
              key={jobId}
              jobId={jobId}
              initialRevision={overview.revision}
              initialApplicationAnswer={overview?.applicationAnswerDraft ?? ""}
              initialRecruiterMessage={overview?.recruiterMessageDraft ?? ""}
              onSaved={load}
              onDirtyChange={setPackageDraftsDirty}
            />}
            {section === "application" && subsection === "submission" && jobId > 0 && <SubmittedPackagesSection key={jobId} jobId={jobId} />}
            {section === "timeline" && subsection === "activity" && jobId > 0 && <ApplicationTimeline jobId={jobId} />}
            {section === "timeline" && subsection === "correspondence" && jobId > 0 && <PageSection surface title={t("workspaceCommunication")} level="h3"><Correspondence jobId={jobId} jobContext={{ companyName: overview?.company, jobTitle: overview?.jobTitle }} /></PageSection>}
          </Box>
        </>}
        {section === "documents" && jobId > 0 && <>
          <PageSection surface title={t("workspaceCurrentDocuments")} description={t("workspaceCurrentDocumentsHelp")} actions={<>
            <Button onClick={() => go("application", "cv")}>{t("workspaceCv")}</Button>
            <Button onClick={() => go("application", "letter")}>{t("workspaceCoverLetter")}</Button>
          </>}><Attachments jobId={jobId} /></PageSection>
          <SubmittedPackagesSection key={jobId} jobId={jobId} allowCapture={false} />
        </>}
        {section === "tasks" && jobId > 0 && <>
          <PageSection surface title={t("workspaceNotes")} actions={<Button startIcon={<EditOutlinedIcon />} onClick={() => setEditOpen(true)}>{t("workspaceEdit")}</Button>}>
            <Typography sx={{ whiteSpace: "pre-wrap", overflowWrap: "anywhere" }}>{overview?.notes || t("workspaceNoNotes")}</Typography>
          </PageSection>
          <PageSection title={t("workspaceChecklist")}><ApplicationChecklist jobId={jobId} onChanged={load} /></PageSection>
          <PageSection surface title={t("calendarTitle")}><ApplicationCalendarActions jobId={jobId} followUpAt={overview?.followUpAt ?? null} deadline={overview?.deadline ?? null} /></PageSection>
        </>}
      </Box>
      <EditJobDialog
        open={editOpen}
        jobId={jobId > 0 ? jobId : null}
        onClose={() => setEditOpen(false)}
        onSaved={() => { setEditOpen(false); void load(); }}
      />
    </Box>
  );
}
function WorkspaceHeader({ overview, onEdit }: { overview: WorkspaceOverview | null; onEdit: () => void }) {
  const { language, t } = useI18n();
  if (!overview) return <Box sx={{ p: 2 }} aria-hidden><Skeleton width="65%" height={34} /><Skeleton width="40%" /></Box>;
  return (
    <Box sx={{ px: { xs: 2, sm: 3 }, pt: 1, pb: 2 }}>
      <PageHeader level="h2" title={overview.jobTitle} description={overview.company ?? undefined} actions={<>
        <Button variant="outlined" startIcon={<EditOutlinedIcon />} onClick={onEdit}>{t("workspaceEditApplication")}</Button>
        {overview.jobUrl ? <Button component="a" href={overview.jobUrl} target="_blank" rel="noopener noreferrer" endIcon={<OpenInNewIcon />}>{t("workspaceOpenAdvert")}</Button> : null}
      </>} />
      <Box sx={{ display: "flex", flexWrap: "wrap", alignItems: "center", gap: 1, mt: 1.5, minWidth: 0 }}>
        <Chip size="small" label={statusLabel(t, overview.status)} color={statusTone(overview.status)} variant="outlined" sx={{ maxWidth: "100%", height: "auto", minHeight: 24, "& .MuiChip-label": { whiteSpace: "normal", overflowWrap: "anywhere" } }} />
        {overview.location ? <Typography variant="body2" color="text.secondary" sx={{ overflowWrap: "anywhere" }}>{overview.location}</Typography> : null}
        {overview.deadline ? <Typography variant="body2" color="text.secondary">{t("jobDetailsDeadline")}: {new Date(overview.deadline).toLocaleDateString(language === "nb" ? "nb-NO" : "en")}</Typography> : null}
      </Box>
      <ApplicationProgress status={overview.status} />
    </Box>
  );
}

function ApplicationProgress({ status }: { status: string }) {
  const { t } = useI18n();
  const normalized = normalizeStatus(status);
  const currentOrder = normalized === "Other" ? 0 : PIPELINE_STATUSES.indexOf(normalized) + 1;
  const isTerminal = normalized === "Rejected" || normalized === "Ghosted" || normalized === "Withdrawn";
  const stages = normalized === "Other" ? [] : isTerminal
    ? [...PIPELINE_STATUSES.filter((stage) => !["Offer", "Rejected", "Ghosted", "Withdrawn"].includes(stage)), normalized]
    : PIPELINE_STATUSES.filter((stage) => !["Rejected", "Ghosted", "Withdrawn"].includes(stage));

  return (
    <Box sx={{ mt: 2 }}>
      <Typography variant="caption" color="text.secondary" sx={{ fontWeight: 700 }}>
        {t("workspaceProgress")}
      </Typography>
      <Box role="region" tabIndex={0} aria-label={`${t("workspaceProgress")}: ${statusLabel(t, status)}`} sx={{ display: "flex", overflowX: "auto", p: 1, mt: 0.5, borderRadius: 1 }}>
        {normalized === "Other" ? <Typography variant="body2" color="text.secondary">{t("workspaceCustomProgress")}</Typography> : null}
        {stages.map((stage, index) => {
          const order = PIPELINE_STATUSES.indexOf(stage) + 1;
          const current = stage === normalized;
          const complete = !current && order < currentOrder;
          return (
            <Box key={stage} sx={{ display: "grid", gridTemplateColumns: index ? "minmax(30px, 1fr) auto" : "auto", alignItems: "center", minWidth: index ? 110 : 72, flex: 1 }}>
              {index > 0 && <Box aria-hidden sx={{ height: 2, bgcolor: complete || current ? "primary.main" : "divider" }} />}
              <Stack aria-current={current ? "step" : undefined} alignItems="center" spacing={0.5} sx={{ minWidth: 72 }}>
                <Box aria-hidden sx={{ width: 12, height: 12, borderRadius: "50%", border: 2, borderColor: current || complete ? "primary.main" : "divider", bgcolor: complete ? "primary.main" : "background.paper", boxShadow: current ? (theme) => `0 0 0 4px ${theme.palette.primary.main}26` : "none" }} />
                <Typography variant="caption" sx={{ whiteSpace: "nowrap", fontWeight: current ? 800 : 600, color: current ? "text.primary" : "text.secondary" }}>
                  {statusLabel(t, stage)}
                </Typography>
              </Stack>
            </Box>
          );
        })}
      </Box>
    </Box>
  );
}

function OverviewSection({ overview, onGo, onReload, onEdit }: {
  overview: WorkspaceOverview | null;
  onGo: (s: string) => void;
  onReload: () => void;
  onEdit: () => void;
}) {
  const { language, t } = useI18n();
  const stats = useMemo(() => overview ? [
    { icon: <DescriptionOutlinedIcon fontSize="small" />, label: t("workspaceCv"), value: overview.cv.variantName ?? (overview.cv.hasTailoredCvText ? t("workspaceTailoredText") : t("workspaceNotPrepared")), ok: !!overview.cv.variantId || overview.cv.hasTailoredCvText, go: "cv" as const },
    { icon: <MailOutlineIcon fontSize="small" />, label: t("jobDetailsCoverLetter"), value: overview.hasCoverLetter ? t("workspaceReady") : t("workspaceNotWritten"), ok: overview.hasCoverLetter, go: "cover-letter" as const },
    { icon: <FolderOutlinedIcon fontSize="small" />, label: t("workspaceDocuments"), value: overview.documentCount ? t("workspaceAttachedCount", { count: overview.documentCount }) : t("assetsNone"), ok: overview.documentCount > 0, go: "documents" as const },
    { icon: <AutoFixHighIcon fontSize="small" />, label: t("workspaceAiSuggestions"), value: overview.aiInteractionCount ? t("workspaceSavedCount", { count: overview.aiInteractionCount }) : t("workspaceNoneYet"), ok: overview.aiInteractionCount > 0, go: "analysis" as const },
    { icon: <ChecklistIcon fontSize="small" />, label: t("workspaceChecklist"), value: overview.checklistProgress ? t("workspaceDoneCount", { completed: overview.checklistProgress.completed, total: overview.checklistProgress.total }) : "—", ok: (overview.checklistProgress?.percent ?? 0) === 100, go: "checklist" as const },
  ] : [], [overview, t]);

  if (!overview) {
    return <Stack spacing={2}>{[0, 1].map((i) => <Skeleton key={i} variant="rounded" height={120} />)}</Stack>;
  }

  const nextStepToken = checklistSystemTranslationToken(overview.nextStep?.key);
  const nextStepLabel = overview.nextStep
    ? nextStepToken ? t(`checklistItem_${nextStepToken}` as any) : overview.nextStep.label
    : null;
  const nextStepReason = overview.nextStep
    ? nextStepToken ? t(`checklistItem_${nextStepToken}Description` as any) : overview.nextStep.reason
    : null;

  return (
    <Stack spacing={2} sx={{ minWidth: 0 }}>
      <PageSection surface title={t("workspaceApplicationInfo")}>
        <Box component="dl" sx={{ m: 0, display: "grid", gridTemplateColumns: { xs: "1fr", sm: "repeat(2, minmax(0, 1fr))", lg: "repeat(4, minmax(0, 1fr))" }, gap: 2 }}>
          {[
            [t("workspaceDiscovered"), overview.savedAt],
            [t("workspaceApplied"), overview.dateApplied],
            [t("jobDetailsDeadline"), overview.deadline],
            [t("intelligenceCategoryFollowUp"), overview.followUpAt],
          ].map(([label, date]) => <Box key={label}>
            <Typography component="dt" variant="caption" color="text.secondary">{label}</Typography>
            <Typography component="dd" variant="body2" sx={{ m: 0, mt: 0.5, fontWeight: 600 }}>{date ? new Date(date).toLocaleDateString(language === "nb" ? "nb-NO" : "en") : "—"}</Typography>
          </Box>)}
        </Box>
      </PageSection>
      {overview.nextStep ? (
        <PageSection surface title={t("workspaceNextAction")}>
          <Typography component="h3" variant="subtitle1" sx={{ fontWeight: 700 }}>{nextStepLabel}</Typography>
          <Typography color="text.secondary" sx={{ mb: 1.5 }}>{nextStepReason}</Typography>
          <Button variant="contained" endIcon={<ArrowForwardIcon />}
            onClick={() => onGo(overview.nextStep?.key === "complete-career-profile" ? "career-profile" : overview.nextStep?.section ?? "checklist")}>
            {nextStepLabel}
          </Button>
        </PageSection>
      ) : (
        <Alert severity="success" sx={{ borderRadius: 3 }}>
          {t("workspaceNothingOutstanding")}
        </Alert>
      )}

      <PageSection title={t("workspacePreparation")}>
      <Box sx={{ display: "grid", gridTemplateColumns: { xs: "1fr", sm: "repeat(2, minmax(0, 1fr))", lg: "repeat(5, minmax(0, 1fr))" }, gap: 1 }}>
        {stats.map((s) => (
          <Button key={s.label} variant="outlined"
            onClick={() => onGo(s.go)}
            sx={{ p: 1.5, display: "block", textAlign: "left", color: "text.primary", borderColor: "divider", minWidth: 0, whiteSpace: "normal", overflowWrap: "anywhere" }}>
            <Stack direction="row" spacing={0.75} alignItems="center" sx={{ color: s.ok ? "success.main" : "text.secondary" }}>
              {s.icon}
              <Typography variant="caption" sx={{ fontWeight: 700 }}>{s.label}</Typography>
            </Stack>
            <Typography variant="body2" sx={{ mt: 0.5, fontWeight: 600 }}>{s.value}</Typography>
          </Button>
        ))}
      </Box>
      </PageSection>

      <PageSection surface title={t("workspaceRecentActivity")} actions={<Button size="small" onClick={onReload}>{t("workspaceRefresh")}</Button>}>
        {overview.recentActivity.length === 0 ? (
          <Typography variant="body2" color="text.secondary">{t("workspaceNoActivity")}</Typography>
        ) : (
          <Stack spacing={0.75}>
            {overview.recentActivity.map((a, i) => (
              <Stack key={i} direction={{ xs: "column", sm: "row" }} spacing={0.5} justifyContent="space-between">
                <Typography variant="body2" sx={{ overflowWrap: "anywhere" }}><strong>{a.type}</strong>{a.detail ? ` — ${a.detail}` : ""}</Typography>
                <Typography variant="caption" color="text.secondary" sx={{ flexShrink: 0 }}>{new Date(a.at).toLocaleDateString(language === "nb" ? "nb-NO" : "en")}</Typography>
              </Stack>
            ))}
          </Stack>
        )}
      </PageSection>

      <OverviewDetails overview={overview} onEdit={onEdit} />
    </Stack>
  );
}

function OverviewDetails({ overview, onEdit }: { overview: WorkspaceOverview; onEdit: () => void }) {
  const { t } = useI18n();
  const [params] = useSearchParams();
  const prefix = useId();
  const triggers = useRef<Record<string, HTMLDivElement | null>>({});
  const targets: Record<string, string> = { "job-details": "details" };
  const key = params.get("section") ?? "";
  const target = Object.prototype.hasOwnProperty.call(targets, key) ? targets[key] : undefined;
  const [expanded, setExpanded] = useState<Record<string, boolean>>({});
  useEffect(() => {
    if (!target) return;
    setExpanded((current) => ({ ...current, [target]: true }));
    triggers.current[target]?.focus();
  }, [target]);
  const panels = [
    { id: "details", title: t("workspaceJobDetails"), content: <JobDetailsSection overview={overview} onEdit={onEdit} /> },
  ];
  return (
    <Box>
      {panels.map((panel) => (
        <Accordion key={panel.id} expanded={!!expanded[panel.id]} onChange={(_, open) => setExpanded((current) => ({ ...current, [panel.id]: open }))} disableGutters elevation={0} sx={{ border: 1, borderColor: "divider", "&:not(:last-child)": { borderBottom: 0 }, "&:before": { display: "none" } }}>
          <AccordionSummary ref={(node: HTMLDivElement | null) => { triggers.current[panel.id] = node; }} expandIcon={<ExpandMoreIcon />} aria-controls={`${prefix}-${panel.id}-content`} id={`${prefix}-${panel.id}-header`}>
            <Typography sx={{ fontWeight: 750 }}>{panel.title}</Typography>
          </AccordionSummary>
          <AccordionDetails sx={{ px: { xs: 1, sm: 2 }, pb: 2 }}>{panel.content}</AccordionDetails>
        </Accordion>
      ))}
    </Box>
  );
}

function workspaceSectionLabel(t: (key: any) => string, section: WorkspaceSectionKey): string {
  const keys: Record<WorkspaceSectionKey, any> = {
    overview: "workspaceOverview",
    match: "workspaceMatch",
    application: "workspaceApplication",
    documents: "workspaceDocuments",
    timeline: "workspaceTimeline",
    tasks: "workspaceTasks",
    interview: "workspaceInterviewPrep",
  };
  return t(keys[section]);
}

function JobDetailsSection({ overview, onEdit }: { overview: WorkspaceOverview | null; onEdit: () => void }) {
  const { language, t } = useI18n();
  if (!overview) return <Skeleton variant="rounded" height={200} />;
  const rows: [string, string][] = [
    [t("company"), overview.company ?? "—"],
    [t("location"), overview.location ?? "—"],
    [t("workspaceCountry"), overview.countryCode ?? "—"],
    [t("workspaceSource"), overview.source ?? "—"],
    [t("jobDetailsSalary"), overview.salary ?? "—"],
    [t("addJobModalStatus"), statusLabel(t, overview.status)],
    [t("workspaceDiscovered"), overview.savedAt ? new Date(overview.savedAt).toLocaleDateString(language === "nb" ? "nb-NO" : "en") : "—"],
    [t("workspaceApplied"), overview.dateApplied ? new Date(overview.dateApplied).toLocaleDateString(language === "nb" ? "nb-NO" : "en") : "—"],
    [t("jobDetailsDeadline"), overview.deadline ? new Date(overview.deadline).toLocaleDateString(language === "nb" ? "nb-NO" : "en") : "—"],
    [t("intelligenceCategoryFollowUp"), overview.followUpAt ? new Date(overview.followUpAt).toLocaleDateString(language === "nb" ? "nb-NO" : "en") : t("workspaceNotScheduled")],
    [t("workspaceNextAction"), overview.nextAction ?? "—"],
  ];
  return (
    <Stack spacing={2}>
      <Paper sx={{ p: 2.5, borderRadius: 3 }}>
        <Stack direction="row" alignItems="center" justifyContent="space-between" gap={1} sx={{ mb: 1.5 }}>
          <Typography variant="subtitle1" sx={{ fontWeight: 800 }}>{t("workspaceApplicationInfo")}</Typography>
          <Button size="small" startIcon={<EditOutlinedIcon />} onClick={onEdit}>{t("workspaceEdit")}</Button>
        </Stack>
        <Box sx={{ display: "grid", gridTemplateColumns: { xs: "1fr", sm: "repeat(2, minmax(0, 1fr))", lg: "repeat(4, minmax(0, 1fr))" }, gap: 1.5 }}>
          {rows.map(([k, v]) => (
            <Box key={k} sx={{ minWidth: 0 }}>
              <Typography variant="caption" color="text.secondary" sx={{ fontWeight: 700 }}>{k}</Typography>
              <Typography variant="body2" sx={{ overflowWrap: "anywhere" }}>{v}</Typography>
            </Box>
          ))}
        </Box>
        {overview.tags.length > 0 ? (
          <Box sx={{ display: "flex", flexWrap: "wrap", gap: 0.75, mt: 2 }}>
            {overview.tags.map((tag) => <Chip key={tag} size="small" label={tag} />)}
          </Box>
        ) : null}
        {overview.notes ? (
          <Box sx={{ mt: 2 }}>
            <Typography variant="caption" color="text.secondary" sx={{ fontWeight: 700 }}>{t("workspaceNotes")}</Typography>
            <Typography variant="body2" sx={{ mt: 0.5, whiteSpace: "pre-wrap", overflowWrap: "anywhere" }}>{overview.notes}</Typography>
          </Box>
        ) : null}
      </Paper>

      <Paper sx={{ p: { xs: 2, sm: 2.5 }, borderRadius: 3 }}>
        <Typography variant="subtitle1" sx={{ fontWeight: 800, mb: 1.5 }}>{t("workspaceJobDescription")}</Typography>
        {!overview.hasJobDescription ? (
          <Alert severity="warning" sx={{ borderRadius: 2 }} action={<Button color="inherit" size="small" onClick={onEdit}>{t("workspaceAddAdvert")}</Button>}>
            {t("workspaceNoJobDescription")}
          </Alert>
        ) : (
          <Stack spacing={2.5}>
            {overview.translatedDescription ? (
              <Box>
                <Typography variant="overline" color="text.secondary">{t("workspaceTranslatedAdvert")}</Typography>
                <Typography sx={{ mt: 0.5, whiteSpace: "pre-wrap", overflowWrap: "anywhere", lineHeight: 1.7 }}>{overview.translatedDescription}</Typography>
              </Box>
            ) : null}
            {overview.description ? (
              <Box>
                {overview.translatedDescription ? <Typography variant="overline" color="text.secondary">{t("workspaceOriginalAdvert")}{overview.descriptionLanguage ? ` · ${overview.descriptionLanguage.toUpperCase()}` : ""}</Typography> : null}
                <Typography sx={{ mt: 0.5, whiteSpace: "pre-wrap", overflowWrap: "anywhere", lineHeight: 1.7 }}>{overview.description}</Typography>
              </Box>
            ) : null}
          </Stack>
        )}
      </Paper>
    </Stack>
  );
}