import {
  CalendarPlus,
  FilePlus2,
  ListPlus,
  Pencil,
  Plus,
  Search,
  ShieldCheck,
  Vote
} from "lucide-react";
import { useCallback, useEffect, useMemo, useState, type ReactNode } from "react";
import { ActionBlockerHint,
  Button,
  DocumentationHelpLink,
  DismissibleAlert,
  FilterBar,
  IconButton,
  LoadingIndicator,
  PageScrollViewport,
  StatePanel,
  StatusBadge,
  hasScope,
  i18nMessage,
  usePlatformLanguage,
  WorkspaceActionBar,
  WorkspaceFrame,
  type PlatformRouteContext
} from "@govoplan/core-webui";
import {
  listCommitteeRecords,
  type CommitteeObjectKind,
  type CommitteeRecord
} from "../../api/committee";
import CommitteeBallotDialog from "./CommitteeBallotDialog";
import CommitteeRecordDialog from "./CommitteeRecordDialog";
import {
  COMMITTEE_DOCUMENTATION,
  COMMITTEE_INTERFACE_I18N,
  committeeDisabledReason
} from "./interfacePatterns";
import { canReviseCommitteeRecord } from "./lifecycle";


type EditorTarget = {
  kind: CommitteeObjectKind;
  parentId?: string | null;
  record?: CommitteeRecord | null;
};

export default function CommitteePage({ settings, auth }: PlatformRouteContext) {
  const { language, translateText } = usePlatformLanguage();
  const tenantId = auth.active_tenant?.id ?? auth.tenant.id;
  const canWrite = hasScope(auth, "committee:workspace:write");
  const canFinalizeBallot = hasScope(auth, "committee:ballot:finalize");
  const [query, setQuery] = useState("");
  const [bodies, setBodies] = useState<CommitteeRecord[]>([]);
  const [meetings, setMeetings] = useState<CommitteeRecord[]>([]);
  const [agendaItems, setAgendaItems] = useState<CommitteeRecord[]>([]);
  const [votes, setVotes] = useState<CommitteeRecord[]>([]);
  const [minutes, setMinutes] = useState<CommitteeRecord[]>([]);
  const [bodyId, setBodyId] = useState("");
  const [meetingId, setMeetingId] = useState("");
  const [agendaId, setAgendaId] = useState("");
  const [editor, setEditor] = useState<EditorTarget | null>(null);
  const [ballotRecord, setBallotRecord] = useState<CommitteeRecord | null>(null);
  const [loading, setLoading] = useState(true);
  const [error, setError] = useState("");
  const selectedBody = bodies.find((item) => item.object_id === bodyId) ?? null;
  const selectedMeeting = meetings.find((item) => item.object_id === meetingId) ?? null;
  const selectedAgenda = agendaItems.find((item) => item.object_id === agendaId) ?? null;

  const loadBodies = useCallback(async (signal?: AbortSignal) => {
    const response = await listCommitteeRecords(
      settings,
      "body",
      { query: query.trim(), limit: 200 },
      signal
    );
    setBodies(response.records);
    setBodyId((current) => response.records.some((item) => item.object_id === current)
      ? current
      : response.records[0]?.object_id ?? "");
  }, [query, settings]);

  const refresh = useCallback(async () => {
    setLoading(true);
    setError("");
    try {
      await loadBodies();
    } catch (reason) {
      setError(reason instanceof Error ? reason.message : "Committee workspace could not be loaded.");
    } finally {
      setLoading(false);
    }
  }, [loadBodies]);

  useEffect(() => {
    const controller = new AbortController();
    setLoading(true);
    loadBodies(controller.signal).
      catch((reason) => {
        if ((reason as Error).name !== "AbortError") {
          setError(reason instanceof Error ? reason.message : "Committee bodies could not be loaded.");
        }
      }).
      finally(() => setLoading(false));
    return () => controller.abort();
  }, [loadBodies]);

  useEffect(() => {
    if (!bodyId) {
      setMeetings([]);
      setMeetingId("");
      return;
    }
    const controller = new AbortController();
    listCommitteeRecords(settings, "meeting", { parentId: bodyId }, controller.signal).
      then((response) => {
        setMeetings(response.records);
        setMeetingId((current) => response.records.some((item) => item.object_id === current)
          ? current
          : response.records[0]?.object_id ?? "");
      }).
      catch((reason) => {
        if ((reason as Error).name !== "AbortError") {
          setError(reason instanceof Error ? reason.message : "Committee meetings could not be loaded.");
        }
      });
    return () => controller.abort();
  }, [bodyId, settings]);

  useEffect(() => {
    if (!meetingId) {
      setAgendaItems([]);
      setMinutes([]);
      setAgendaId("");
      return;
    }
    const controller = new AbortController();
    Promise.all([
      listCommitteeRecords(settings, "agenda_item", { parentId: meetingId }, controller.signal),
      listCommitteeRecords(settings, "minute", { parentId: meetingId }, controller.signal)
    ]).
      then(([agenda, nextMinutes]) => {
        const ordered = [...agenda.records].sort(
          (left, right) => Number(left.attributes.position ?? 0) - Number(right.attributes.position ?? 0)
        );
        setAgendaItems(ordered);
        setMinutes(nextMinutes.records);
        setAgendaId((current) => ordered.some((item) => item.object_id === current)
          ? current
          : ordered[0]?.object_id ?? "");
      }).
      catch((reason) => {
        if ((reason as Error).name !== "AbortError") {
          setError(reason instanceof Error ? reason.message : "Meeting details could not be loaded.");
        }
      });
    return () => controller.abort();
  }, [meetingId, settings]);

  useEffect(() => {
    if (!agendaId) {
      setVotes([]);
      return;
    }
    const controller = new AbortController();
    listCommitteeRecords(settings, "vote", { parentId: agendaId }, controller.signal).
      then((response) => setVotes(response.records)).
      catch((reason) => {
        if ((reason as Error).name !== "AbortError") {
          setError(reason instanceof Error ? reason.message : "Votes could not be loaded.");
        }
      });
    return () => controller.abort();
  }, [agendaId, settings]);

  const meetingTime = useMemo(
    () => selectedMeeting
      ? `${formatDateTime(selectedMeeting.attributes.starts_at, language)} - ${formatTime(selectedMeeting.attributes.ends_at, language)}`
      : "",
    [language, selectedMeeting]
  );

  return (
    <main className="committee-page">
      <WorkspaceFrame className="committee-shell" label="Committee workspace" interfaceId="committee.workspace" helpContextId="committee.page.workspace" helpModuleId="committee">
        <WorkspaceActionBar
          title="Committee"
          titleHelp={<DocumentationHelpLink reference={COMMITTEE_DOCUMENTATION} />}
          scope="workspace"
          variant="collection"
          refreshable
          reloadAction={{ onReload: () => void refresh(), loading }}
          className="committee-toolbar"
          contextActions={<FilterBar as="form" surface="control" wrap="never" width="compact" onSubmit={(event) => { event.preventDefault(); void refresh(); }} className="committee-search">
            <Search size={16} aria-hidden="true" />
            <input value={query} onChange={(event) => setQuery(event.target.value)} placeholder="Search bodies" aria-label="Search committee bodies" />
          </FilterBar>}
          createAction={<Button
            variant="primary"
            disabled={!canWrite || loading}
            disabledReason={committeeDisabledReason({ loading, permitted: canWrite })}
            onClick={() => setEditor({ kind: "body" })}
          >
            <Plus size={16} aria-hidden="true" />
            New body
          </Button>}
        />

        {error ? <DismissibleAlert tone="danger" resetKey={error} className="committee-alert">{error}</DismissibleAlert> : null}
        {loading && bodies.length === 0 ? <LoadingIndicator label="Loading committee workspace" /> : null}
        {!canWrite ? (
          <ActionBlockerHint
            tone="info"
            reason={{
              summary: "No Committee management permission",
              details: COMMITTEE_INTERFACE_I18N.writeReason,
              requiredAction: COMMITTEE_INTERFACE_I18N.permissionAction,
              actor: COMMITTEE_INTERFACE_I18N.permissionActor,
              target: COMMITTEE_INTERFACE_I18N.permissionDestination
            }}
            labels={{
              requiredAction: COMMITTEE_INTERFACE_I18N.requiredAction,
              actor: COMMITTEE_INTERFACE_I18N.actor,
              target: COMMITTEE_INTERFACE_I18N.destination
            }}
            documentation={COMMITTEE_DOCUMENTATION}
          />
        ) : null}

        <div className="committee-workspace">
          <section className="committee-panel committee-body-panel" aria-label="Committee bodies">
            <PanelHeading title="Bodies" count={bodies.length} />
            <PageScrollViewport className="committee-panel-scroll">
              <RecordList records={bodies} selectedId={bodyId} onSelect={setBodyId} />
            </PageScrollViewport>
            {selectedBody ? (
              <div className="committee-panel-actions">
                <IconButton
                  label="Edit body"
                  icon={<Pencil size={16} />}
                  disabled={!canWrite || !canReviseCommitteeRecord(selectedBody)}
                  disabledReason={committeeDisabledReason({ permitted: canWrite, lifecycleBlocked: !canReviseCommitteeRecord(selectedBody) })}
                  onClick={() => setEditor({ kind: "body", record: selectedBody })}
                />
                <Button
                  variant="primary"
                  disabled={!canWrite}
                  disabledReason={committeeDisabledReason({ permitted: canWrite })}
                  onClick={() => setEditor({ kind: "meeting", parentId: selectedBody.object_id })}
                >
                  <CalendarPlus size={16} aria-hidden="true" />
                  New meeting
                </Button>
              </div>
            ) : null}
          </section>

          <section className="committee-panel committee-meeting-panel" aria-label="Meetings">
            <PanelHeading title="Meetings" count={meetings.length} />
            <PageScrollViewport className="committee-panel-scroll">
              <RecordList records={meetings} selectedId={meetingId} onSelect={setMeetingId} secondary={(record) => meetingSecondary(record, language, translateText)} />
            </PageScrollViewport>
          </section>

          <section className="committee-detail" aria-label="Meeting workspace">
            {!selectedMeeting ? (
              <StatePanel size="fill" title="Meetings" description="Select or create a meeting." />
            ) : (
              <>
                <div className="committee-detail-heading">
                  <div>
                    <span>{meetingTime}</span>
                    <h1>{selectedMeeting.title}</h1>
                  </div>
                  <StatusBadge status={statusTone(selectedMeeting.state)} label={stateLabel(selectedMeeting.state)} />
                  <IconButton
                    label="Edit meeting"
                    icon={<Pencil size={16} />}
                    disabled={!canWrite || !canReviseCommitteeRecord(selectedMeeting)}
                    disabledReason={committeeDisabledReason({ permitted: canWrite, lifecycleBlocked: !canReviseCommitteeRecord(selectedMeeting) })}
                    onClick={() => setEditor({ kind: "meeting", record: selectedMeeting })}
                  />
                </div>
                <PageScrollViewport className="committee-detail-scroll">
                  <WorkspaceSection
                    title="Agenda"
                    action={(
                      <Button
                        variant="ghost"
                        disabled={!canWrite}
                        disabledReason={committeeDisabledReason({ permitted: canWrite })}
                        onClick={() => setEditor({ kind: "agenda_item", parentId: selectedMeeting.object_id })}
                      >
                        <ListPlus size={16} aria-hidden="true" />
                        Add item
                      </Button>
                    )}
                  >
                    <div className="committee-agenda-list">
                      {agendaItems.map((item) => (
                        <div key={item.object_id} className={item.object_id === agendaId ? "is-selected" : ""}>
                          <button type="button" onClick={() => setAgendaId(item.object_id)}>
                            <span className="committee-agenda-position">{String(item.attributes.position ?? "-")}</span>
                            <span><strong>{item.title}</strong><small>{stateLabel(item.state)}</small></span>
                          </button>
                          <IconButton
                            label="Edit agenda item"
                            icon={<Pencil size={15} />}
                            disabled={!canWrite || !canReviseCommitteeRecord(item)}
                            disabledReason={committeeDisabledReason({ permitted: canWrite, lifecycleBlocked: !canReviseCommitteeRecord(item) })}
                            onClick={() => setEditor({ kind: "agenda_item", record: item })}
                          />
                        </div>
                      ))}
                      {agendaItems.length === 0 ? <StatePanel size="inline" description="No agenda items." /> : null}
                    </div>
                  </WorkspaceSection>

                  {selectedAgenda ? (
                    <WorkspaceSection
                      title={i18nMessage("i18n:govoplan-committee.votes_for", { title: selectedAgenda.title })}
                      action={(
                        <Button
                          variant="ghost"
                          disabled={!canWrite}
                          disabledReason={committeeDisabledReason({ permitted: canWrite })}
                          onClick={() => setEditor({ kind: "vote", parentId: selectedAgenda.object_id })}
                        >
                          <Vote size={16} aria-hidden="true" />
                          Add vote
                        </Button>
                      )}
                    >
                      <RecordRows
                        records={votes}
                        editDisabledReason={(record) => committeeDisabledReason({ permitted: canWrite, lifecycleBlocked: !canReviseCommitteeRecord(record) })}
                        onEdit={(record) => setEditor({ kind: "vote", record })}
                        detail={(record) => voteSummary(record, translateText)}
                        secondaryAction={(record) => isProviderBallotReady(record) ? (
                          <IconButton
                            label={i18nMessage("i18n:govoplan-committee.finalize_provider_record", { title: record.title })}
                            icon={<ShieldCheck size={15} />}
                            disabled={!canFinalizeBallot}
                            disabledReason={!canFinalizeBallot ? COMMITTEE_INTERFACE_I18N.finalizeReason : undefined}
                            onClick={() => setBallotRecord(record)}
                          />
                        ) : null}
                      />
                    </WorkspaceSection>
                  ) : null}

                  <WorkspaceSection
                    title="Minutes"
                    action={(
                      <Button
                        variant="ghost"
                        disabled={!canWrite}
                        disabledReason={committeeDisabledReason({ permitted: canWrite })}
                        onClick={() => setEditor({ kind: "minute", parentId: selectedMeeting.object_id })}
                      >
                        <FilePlus2 size={16} aria-hidden="true" />
                        Add minutes
                      </Button>
                    )}
                  >
                    <RecordRows
                      records={minutes}
                      editDisabledReason={(record) => committeeDisabledReason({ permitted: canWrite, lifecycleBlocked: !canReviseCommitteeRecord(record) })}
                      onEdit={(record) => setEditor({ kind: "minute", record })}
                      detail={(record) => i18nMessage("i18n:govoplan-committee.record_reference", { id: String((record.attributes.content_ref as Record<string, unknown> | undefined)?.object_id ?? "-") })}
                    />
                  </WorkspaceSection>
                </PageScrollViewport>
              </>
            )}
          </section>
        </div>
      </WorkspaceFrame>

      {editor ? (
        <CommitteeRecordDialog
          settings={settings}
          tenantId={tenantId}
          kind={editor.kind}
          parentId={editor.parentId}
          record={editor.record}
          open
          onClose={() => setEditor(null)}
          onSaved={() => void refresh()}
        />
      ) : null}
      {ballotRecord ? (
        <CommitteeBallotDialog
          settings={settings}
          record={ballotRecord}
          open
          onClose={() => setBallotRecord(null)}
          onSaved={() => void refresh()}
        />
      ) : null}
    </main>
  );
}

function PanelHeading({ title, count }: { title: string; count: number }) {
  return <div className="committee-panel-heading"><h2>{title}</h2><span>{count}</span></div>;
}

function RecordList({ records, selectedId, onSelect, secondary }: {
  records: CommitteeRecord[];
  selectedId: string;
  onSelect: (id: string) => void;
  secondary?: (record: CommitteeRecord) => string;
}) {
  if (records.length === 0) return <StatePanel size="inline" description="No records." />;
  return <div className="committee-record-list">{records.map((record) => (
    <button key={record.object_id} type="button" className={record.object_id === selectedId ? "is-selected" : ""} onClick={() => onSelect(record.object_id)}>
      <strong>{record.title}</strong>
      <span>{secondary?.(record) ?? stateLabel(record.state)}</span>
    </button>
  ))}</div>;
}

function WorkspaceSection({ title, action, children }: { title: string; action?: ReactNode; children: ReactNode }) {
  return <section className="committee-workspace-section"><div><h2>{title}</h2>{action}</div>{children}</section>;
}

function RecordRows({ records, editDisabledReason, onEdit, detail, secondaryAction }: {
  records: CommitteeRecord[];
  editDisabledReason: (record: CommitteeRecord) => string | undefined;
  onEdit: (record: CommitteeRecord) => void;
  detail: (record: CommitteeRecord) => string;
  secondaryAction?: (record: CommitteeRecord) => ReactNode;
}) {
  if (records.length === 0) return <StatePanel size="inline" description="No records." />;
  return <div className="committee-record-rows">{records.map((record) => (
    <div key={record.object_id}>
      <span><strong>{record.title}</strong><small>{detail(record)}</small></span>
      <StatusBadge status={statusTone(record.state)} label={stateLabel(record.state)} />
      <span className="committee-row-actions">
        {secondaryAction?.(record)}
        <IconButton
          label={i18nMessage("i18n:govoplan-committee.edit_record", { title: record.title })}
          icon={<Pencil size={15} />}
          disabled={Boolean(editDisabledReason(record))}
          disabledReason={editDisabledReason(record)}
          onClick={() => onEdit(record)}
        />
      </span>
    </div>
  ))}</div>;
}

function meetingSecondary(record: CommitteeRecord, locale: string, translateText: (value: string) => string): string {
  return `${formatDateTime(record.attributes.starts_at, locale)} - ${translateText(stateLabel(record.state))}`;
}

function voteSummary(record: CommitteeRecord, translateText: (value: string) => string): string {
  const cast = Number(record.attributes.cast_count ?? 0);
  const eligible = Number(record.attributes.eligible_count ?? 0);
  return i18nMessage("i18n:govoplan-committee.vote_summary", {
    method: translateText(domainLabel(String(record.attributes.method ?? "recorded"))),
    cast,
    eligible
  });
}

function isProviderBallotReady(record: CommitteeRecord): boolean {
  return record.state === "open" && Boolean(
    String(record.attributes.voting_ballot_id ?? "").trim()
    || String(record.attributes.provider_id ?? "").trim()
  );
}

function statusTone(state: string): "active" | "inactive" | "warning" {
  if (["active", "open", "accepted", "decided", "closed"].includes(state)) return "active";
  if (["cancelled", "retired", "withdrawn"].includes(state)) return "inactive";
  return "warning";
}

function formatDateTime(value: unknown, locale?: string): string {
  if (!value) return "Date not set";
  return new Intl.DateTimeFormat(locale, { dateStyle: "medium", timeStyle: "short" }).format(new Date(String(value)));
}

function formatTime(value: unknown, locale?: string): string {
  if (!value) return "-";
  return new Intl.DateTimeFormat(locale, { timeStyle: "short" }).format(new Date(String(value)));
}

function stateLabel(value: string): string {
  return `i18n:govoplan-committee.state_${value}`;
}

function domainLabel(value: string): string {
  return `i18n:govoplan-committee.domain_${value}`;
}