"use client";

import { useEffect, useState } from "react";
import { Badge } from "@/components/ui/badge";
import { Button } from "@/components/ui/button";
import { Progress } from "@/components/ui/progress";
import {
  Dialog,
  DialogContent,
  DialogHeader,
  DialogTitle,
  DialogFooter,
} from "@/components/ui/dialog";
import {
  CheckCircle2,
  Clock,
  Eye,
  Loader2,
  Trash2,
  XCircle,
} from "lucide-react";
import { useMutation, useQueryClient } from "@tanstack/react-query";
import { apiRequest } from "@/lib/api/client";
import { casesKeys } from "@/lib/api/cases";
import type { CaseDetail, CaseDocument } from "@/lib/api/cases";

/*
 * Document list for the case detail "מסמכים" tab. Uses the real document
 * row shape returned by the FastAPI case_get endpoint — see db.list_documents
 * and the `documents` schema in legal_mcp/services/db.py:
 *   id · case_id · doc_type · title · file_path · extraction_status ·
 *   page_count · created_at · practice_area · appeal_subtype
 */

const DOC_TYPE_LABELS: Record<string, string> = {
  appeal:    "כתב ערר",
  response:  "כתב תשובה",
  protocol:  "פרוטוקול",
  decision:  "החלטת ועדה מקומית",
  plan:      "תכנית",
  reference: "חומר רקע",
  auto:      "—",
};

function doctypeLabel(t: string): string {
  return DOC_TYPE_LABELS[t] ?? t;
}

function doctypeTone(t: string): string {
  switch (t) {
    case "appeal":    return "bg-info-bg text-info border-info/40";
    case "response":  return "bg-gold-wash text-gold-deep border-gold/40";
    case "decision":  return "bg-success-bg text-success border-success/40";
    case "protocol":  return "bg-warn-bg text-warn border-warn/40";
    default:          return "bg-rule-soft text-ink-muted border-rule";
  }
}

const STATUS_LABELS: Record<string, string> = {
  pending:    "בהמתנה",
  processing: "בעיבוד",
  completed:  "הושלם",
  proofread:  "הוגה",
  failed:     "נכשל",
  error:      "שגיאה",
};

/** Sort priority — lower = higher in list */
const STATUS_ORDER: Record<string, number> = {
  failed:     0,
  error:      0,
  processing: 1,
  pending:    2,
  completed:  3,
  proofread:  3,
};

function statusOrder(s: string): number {
  return STATUS_ORDER[s] ?? 3;
}

function StatusIcon({ status }: { status: string }) {
  switch (status) {
    case "completed":
    case "proofread":
      return <CheckCircle2 className="w-4 h-4 text-success shrink-0" />;
    case "processing":
      return <Loader2 className="w-4 h-4 text-gold animate-spin shrink-0" />;
    case "pending":
      return <Clock className="w-4 h-4 text-ink-muted shrink-0" />;
    case "failed":
    case "error":
      return <XCircle className="w-4 h-4 text-danger shrink-0" />;
    default:
      return <Clock className="w-4 h-4 text-ink-muted shrink-0" />;
  }
}

function formatDate(iso: string) {
  if (!iso) return "—";
  try {
    return new Date(iso).toLocaleDateString("he-IL");
  } catch {
    return iso;
  }
}

function filenameFromPath(path: string): string {
  const parts = path.split("/");
  return parts[parts.length - 1] || path;
}

/* ── Document text preview dialog ──────────────────────────────── */

function DocumentPreviewDialog({
  doc,
  open,
  onOpenChange,
}: {
  doc: CaseDocument;
  open: boolean;
  onOpenChange: (v: boolean) => void;
}) {
  const [text, setText] = useState<string | null>(null);
  const [loading, setLoading] = useState(false);
  const [error, setError] = useState<string | null>(null);

  useEffect(() => {
    if (!open) {
      setText(null);
      setError(null);
      return;
    }
    let cancelled = false;
    setLoading(true);
    setError(null);
    apiRequest<{ text: string }>(`/api/documents/${doc.id}/text`)
      .then((res) => { if (!cancelled) setText(res.text || "(ריק)"); })
      .catch(() => { if (!cancelled) setError("המסמך עדיין לא עובד או שאין בו טקסט"); })
      .finally(() => { if (!cancelled) setLoading(false); });
    return () => { cancelled = true; };
  }, [open, doc.id]);

  const displayName = doc.title || filenameFromPath(doc.file_path);

  return (
    <Dialog open={open} onOpenChange={onOpenChange}>
      <DialogContent className="sm:max-w-2xl max-h-[80vh] flex flex-col" dir="rtl">
        <DialogHeader>
          <DialogTitle className="text-right">{displayName}</DialogTitle>
        </DialogHeader>
        <div className="flex-1 overflow-hidden">
          {loading && (
            <div className="flex items-center justify-center py-12">
              <Loader2 className="w-6 h-6 animate-spin text-gold" />
              <span className="ms-2 text-ink-muted text-sm">טוען מסמך...</span>
            </div>
          )}
          {error && (
            <div className="text-center py-12 text-danger text-sm">{error}</div>
          )}
          {text !== null && !loading && (
            <div className="h-[60vh] overflow-y-auto" dir="rtl">
              <pre className="whitespace-pre-wrap text-sm text-ink leading-relaxed font-sans p-2">
                {text}
              </pre>
            </div>
          )}
        </div>
        <DialogFooter showCloseButton />
      </DialogContent>
    </Dialog>
  );
}

/* ── Delete confirmation dialog ────────────────────────────────── */

function DeleteConfirmDialog({
  doc,
  caseNumber,
  open,
  onOpenChange,
}: {
  doc: CaseDocument;
  caseNumber: string;
  open: boolean;
  onOpenChange: (v: boolean) => void;
}) {
  const qc = useQueryClient();
  const deleteMutation = useMutation({
    mutationFn: () =>
      apiRequest(`/api/cases/${caseNumber}/documents/${doc.id}`, {
        method: "DELETE",
      }),
    onSuccess: () => {
      qc.invalidateQueries({ queryKey: casesKeys.all });
      onOpenChange(false);
    },
  });

  const displayName = doc.title || filenameFromPath(doc.file_path);

  return (
    <Dialog open={open} onOpenChange={onOpenChange}>
      <DialogContent dir="rtl">
        <DialogHeader>
          <DialogTitle className="text-right">מחיקת מסמך</DialogTitle>
        </DialogHeader>
        <p className="text-sm text-ink-muted text-right">
          האם למחוק את המסמך <strong>&ldquo;{displayName}&rdquo;</strong>?
          <br />
          פעולה זו אינה ניתנת לביטול.
        </p>
        <DialogFooter>
          <Button
            variant="destructive"
            onClick={() => deleteMutation.mutate()}
            disabled={deleteMutation.isPending}
          >
            {deleteMutation.isPending ? (
              <Loader2 className="w-4 h-4 animate-spin me-1" />
            ) : (
              <Trash2 className="w-4 h-4 me-1" />
            )}
            מחק
          </Button>
          <Button variant="outline" onClick={() => onOpenChange(false)}>
            ביטול
          </Button>
        </DialogFooter>
      </DialogContent>
    </Dialog>
  );
}

/* ── Single document row ───────────────────────────────────────── */

function DocumentRow({
  doc,
  caseNumber,
}: {
  doc: CaseDocument;
  caseNumber: string;
}) {
  const [previewOpen, setPreviewOpen] = useState(false);
  const [deleteOpen, setDeleteOpen] = useState(false);
  const displayName = doc.title || filenameFromPath(doc.file_path);
  const canPreview =
    doc.extraction_status === "completed" || doc.extraction_status === "proofread";

  return (
    <>
      <li className="py-3 flex items-start gap-3 hover:bg-gold-wash/30 transition-colors px-2 -mx-2 rounded group">
        <StatusIcon status={doc.extraction_status} />
        <button
          type="button"
          className="flex-1 min-w-0 space-y-0.5 text-right cursor-pointer hover:underline decoration-gold/40 underline-offset-2 disabled:cursor-default disabled:no-underline"
          disabled={!canPreview}
          onClick={() => canPreview && setPreviewOpen(true)}
          title={canPreview ? "לחץ לצפייה במסמך" : "המסמך עדיין לא עובד"}
        >
          <div className="text-ink font-medium truncate flex items-center gap-1.5">
            {canPreview && <Eye className="w-3.5 h-3.5 text-ink-muted shrink-0" />}
            <span>{displayName}</span>
          </div>
          <div className="text-[0.72rem] text-ink-muted flex items-center gap-3 flex-wrap">
            {doc.page_count != null && (
              <span className="tabular-nums">{doc.page_count} עמ׳</span>
            )}
            {doc.created_at && <span>{formatDate(doc.created_at)}</span>}
          </div>
        </button>
        {doc.doc_type && (
          <Badge
            variant="outline"
            className={`rounded-full px-2 py-0.5 text-[0.7rem] shrink-0 ${doctypeTone(doc.doc_type)}`}
          >
            {doctypeLabel(doc.doc_type)}
          </Badge>
        )}
        <button
          type="button"
          className="shrink-0 p-1 rounded text-ink-muted/40 hover:text-danger hover:bg-danger-bg transition-colors opacity-0 group-hover:opacity-100"
          onClick={() => setDeleteOpen(true)}
          title="מחק מסמך"
        >
          <Trash2 className="w-4 h-4" />
        </button>
      </li>
      {previewOpen && (
        <DocumentPreviewDialog
          doc={doc}
          open={previewOpen}
          onOpenChange={setPreviewOpen}
        />
      )}
      {deleteOpen && (
        <DeleteConfirmDialog
          doc={doc}
          caseNumber={caseNumber}
          open={deleteOpen}
          onOpenChange={setDeleteOpen}
        />
      )}
    </>
  );
}

/* ── Main panel ────────────────────────────────────────────────── */

export function DocumentsPanel({
  data,
}: {
  data?: CaseDetail;
}) {
  const docs = data?.documents ?? [];
  const caseNumber = data?.case_number ?? "";

  if (docs.length === 0) {
    return (
      <div className="text-center py-12 text-ink-muted">
        <div className="text-gold text-2xl mb-2" aria-hidden="true">❦</div>
        <p className="text-sm">אין מסמכים בתיק זה</p>
      </div>
    );
  }

  const sorted = [...docs].sort(
    (a, b) => statusOrder(a.extraction_status) - statusOrder(b.extraction_status),
  );

  const done = docs.filter(
    (d) => d.extraction_status === "completed" || d.extraction_status === "proofread",
  ).length;
  const processing = docs.filter((d) => d.extraction_status === "processing").length;
  const pending = docs.filter((d) => d.extraction_status === "pending").length;
  const failed = docs.filter(
    (d) => d.extraction_status === "failed" || d.extraction_status === "error",
  ).length;
  const hasIncomplete = processing > 0 || pending > 0 || failed > 0;
  const pct = docs.length > 0 ? Math.round((done / docs.length) * 100) : 0;

  return (
    <div className="space-y-3">
      {hasIncomplete && (
        <div className="rounded-lg border border-rule bg-parchment/40 px-4 py-3 space-y-2" dir="rtl">
          <div className="flex items-center gap-4 text-[0.78rem] flex-wrap">
            {done > 0 && (
              <span className="flex items-center gap-1 text-success">
                <CheckCircle2 className="w-3.5 h-3.5" />
                {done} {STATUS_LABELS.completed}
              </span>
            )}
            {processing > 0 && (
              <span className="flex items-center gap-1 text-gold-deep">
                <Loader2 className="w-3.5 h-3.5 animate-spin" />
                {processing} {STATUS_LABELS.processing}
              </span>
            )}
            {pending > 0 && (
              <span className="flex items-center gap-1 text-ink-muted">
                <Clock className="w-3.5 h-3.5" />
                {pending} {STATUS_LABELS.pending}
              </span>
            )}
            {failed > 0 && (
              <span className="flex items-center gap-1 text-danger">
                <XCircle className="w-3.5 h-3.5" />
                {failed} {STATUS_LABELS.failed}
              </span>
            )}
          </div>
          <Progress
            value={pct}
            className={failed > 0 && done === 0 ? "[&>div]:bg-danger" : ""}
          />
        </div>
      )}

      <div className="max-h-[70vh] overflow-y-auto" dir="rtl">
        <ul className="divide-y divide-rule" dir="rtl">
          {sorted.map((doc) => (
            <DocumentRow key={doc.id} doc={doc} caseNumber={caseNumber} />
          ))}
        </ul>
      </div>
    </div>
  );
}