"use client";

/*
 * Per-decision lessons editor — lives inside CorpusDetailDrawer's
 * "מה למדנו" tab. Lessons are persisted in the decision_lessons table
 * (one-to-many on style_corpus) and consumed by hermes-curator and
 * future style_analyzer runs as context.
 *
 * The chair can:
 *   - Add a lesson typed manually (category = "general" by default)
 *   - Edit / delete existing lessons
 *   - Approve / reject a lesson (review_status — INV-LRN1/G10): only an
 *     approved lesson flows to the writer. This is the SINGLE writer gate;
 *     the old informative-only applied_to_skill flag was removed (LRN-1/INV-IA3).
 *
 * Lessons from the curator arrive with source="curator" and are visually
 * distinguished by a badge so the chair can audit auto-suggestions.
 */

import { useState } from "react";
import {
  Plus, Save, Trash2, Loader2, Check, X, Undo2,
} from "lucide-react";
import { toast } from "sonner";
import { Button } from "@/components/ui/button";
import { Card, CardContent } from "@/components/ui/card";
import { Textarea } from "@/components/ui/textarea";
import { Badge } from "@/components/ui/badge";
import { Skeleton } from "@/components/ui/skeleton";
import {
  Select, SelectContent, SelectItem, SelectTrigger, SelectValue,
} from "@/components/ui/select";
import {
  useAddLesson,
  useCorpusLessons,
  useDeleteLesson,
  usePatchLesson,
  type DecisionLesson,
} from "@/lib/api/training";

const CATEGORIES = [
  { value: "general", label: "כללי" },
  { value: "style", label: "סגנון" },
  { value: "structure", label: "מבנה" },
  { value: "lexicon", label: "לקסיקון" },
  { value: "tabular", label: "טבלאי" },
] as const;

// All labels in Hebrew. Keyed loosely (string) so new sources — e.g. the
// two-judge style panel — render correctly with a graceful fallback.
const SOURCE_BADGE: Record<string, { label: string; cls: string }> = {
  manual: { label: "ידני", cls: "bg-rule-soft text-ink-soft" },
  chair: { label: "יו״ר", cls: "bg-gold-wash text-gold-deep" },
  curator: { label: "הרמס (סקירה)", cls: "bg-info-bg text-info" },
  style_analyzer: { label: "מנתח-סגנון", cls: "bg-success-bg text-success" },
  "panel:deepseek+gemini": { label: "פאנל: דיפסיק+גמיני", cls: "bg-gold-wash text-gold-deep" },
  // #158/INV-LRN8 — a super-lesson merging overlapping lessons; navy-filled so it
  // reads as the consolidated/elevated one.
  synthesis: { label: "סינתזה", cls: "bg-navy text-parchment" },
};

const SOURCE_BADGE_FALLBACK = { label: "פאנל", cls: "bg-rule-soft text-ink-soft" };

// review gate (INV-LRN1/G10): only "approved" lessons flow to the writer.
const REVIEW_BADGE: Record<string, { label: string; cls: string }> = {
  proposed: { label: "ממתין לאישור", cls: "bg-gold-wash text-gold-deep border-gold/40" },
  approved: { label: "מאושר · זורם לכותב", cls: "bg-success-bg text-success border-success/40" },
  rejected: { label: "נדחה", cls: "bg-rule-soft text-ink-muted line-through" },
  // #158/INV-LRN8 — merged into a synthesis super-lesson; kept as provenance, no
  // longer fed to the writer. Muted (not struck — it wasn't rejected).
  superseded: { label: "מוזג", cls: "bg-rule-soft text-ink-muted" },
};

export function LessonsTab({ corpusId }: { corpusId: string }) {
  const { data, isPending } = useCorpusLessons(corpusId);
  const add = useAddLesson(corpusId);
  const [draftText, setDraftText] = useState("");
  const [draftCategory, setDraftCategory] = useState<DecisionLesson["category"]>("general");

  const onAdd = async () => {
    const text = draftText.trim();
    if (!text) return;
    try {
      await add.mutateAsync({ lesson_text: text, category: draftCategory });
      setDraftText("");
      setDraftCategory("general");
      toast.success("הלקח נוסף");
    } catch (e) {
      toast.error(e instanceof Error ? e.message : "כשל בשמירה");
    }
  };

  return (
    <div className="space-y-4">
      {/* Composer */}
      <Card className="bg-surface border-rule">
        <CardContent className="px-4 py-3 space-y-2">
          <h4 className="text-[0.78rem] uppercase tracking-wider text-gold-deep font-semibold">
            הוסף לקח להחלטה
          </h4>
          <Textarea
            value={draftText}
            onChange={(e) => setDraftText(e.target.value)}
            placeholder="מה למדנו מההחלטה הזו? למשל: 'דפנה מעדיפה הוצאות מתונות (5K-10K ₪) גם בערר שהתקבל במלואו'"
            rows={3}
            dir="rtl"
            disabled={add.isPending}
          />
          <div className="flex items-center gap-2">
            <Select
              value={draftCategory}
              onValueChange={(v) => setDraftCategory(v as DecisionLesson["category"])}
              disabled={add.isPending}
              dir="rtl"
            >
              <SelectTrigger className="w-40">
                <SelectValue />
              </SelectTrigger>
              <SelectContent>
                {CATEGORIES.map((c) => (
                  <SelectItem key={c.value} value={c.value}>{c.label}</SelectItem>
                ))}
              </SelectContent>
            </Select>
            <div className="grow" />
            <Button onClick={onAdd} disabled={add.isPending || !draftText.trim()}
              className="bg-navy text-parchment hover:bg-navy-soft">
              {add.isPending ? (
                <Loader2 className="w-4 h-4 animate-spin me-1" />
              ) : (
                <Plus className="w-4 h-4 me-1" />
              )}
              שמור לקח
            </Button>
          </div>
        </CardContent>
      </Card>

      {/* List */}
      {isPending ? (
        <div className="space-y-2">
          {[...Array(3)].map((_, i) => (
            <Skeleton key={i} className="h-16 w-full" />
          ))}
        </div>
      ) : !data || data.length === 0 ? (
        <p className="text-center text-ink-muted text-sm py-6">
          אין עדיין לקחים להחלטה זו. הוסף לקח ראשון מלמעלה.
        </p>
      ) : (
        <div className="space-y-2">
          {data.map((lesson) => (
            <LessonItem key={lesson.id} lesson={lesson} corpusId={corpusId} />
          ))}
        </div>
      )}
    </div>
  );
}

function LessonItem({
  lesson, corpusId,
}: { lesson: DecisionLesson; corpusId: string }) {
  const [editing, setEditing] = useState(false);
  const [text, setText] = useState(lesson.lesson_text);
  const [category, setCategory] = useState<DecisionLesson["category"]>(lesson.category);
  const patch = usePatchLesson(corpusId);
  const del = useDeleteLesson(corpusId);

  const sourceBadge = SOURCE_BADGE[lesson.source] ?? SOURCE_BADGE_FALLBACK;
  const reviewBadge = REVIEW_BADGE[lesson.review_status] ?? REVIEW_BADGE.proposed;
  const dirty = text !== lesson.lesson_text || category !== lesson.category;

  const onSetReview = async (review_status: DecisionLesson["review_status"]) => {
    try {
      await patch.mutateAsync({ id: lesson.id, patch: { review_status } });
      toast.success(
        review_status === "approved" ? "אושר — הלקח יזרום לכותב"
        : review_status === "rejected" ? "נדחה — לא יזרום לכותב"
        : "הוחזר להמתנה",
      );
    } catch (e) {
      toast.error(e instanceof Error ? e.message : "כשל בעדכון");
    }
  };

  const onSave = async () => {
    try {
      await patch.mutateAsync({
        id: lesson.id,
        patch: dirty ? { lesson_text: text, category } : {},
      });
      setEditing(false);
      toast.success("הלקח עודכן");
    } catch (e) {
      toast.error(e instanceof Error ? e.message : "כשל בעדכון");
    }
  };

  const onDelete = async () => {
    if (!window.confirm("למחוק את הלקח?")) return;
    try {
      await del.mutateAsync(lesson.id);
      toast.success("נמחק");
    } catch (e) {
      toast.error(e instanceof Error ? e.message : "כשל במחיקה");
    }
  };

  const mergedCount = lesson.source === "synthesis" ? (lesson.synthesized_from?.length ?? 0) : 0;

  return (
    <Card className={`bg-surface border-rule ${lesson.review_status === "superseded" ? "opacity-70" : ""}`}>
      <CardContent className="px-4 py-3 space-y-2">
        <div className="flex items-center gap-2 text-[0.72rem]">
          <Badge variant="outline"
            className="bg-rule-soft text-ink-soft">
            {CATEGORIES.find((c) => c.value === lesson.category)?.label || lesson.category}
          </Badge>
          <Badge variant="outline" className={sourceBadge.cls}>
            {sourceBadge.label}
          </Badge>
          <Badge variant="outline" className={reviewBadge.cls}>
            {reviewBadge.label}
          </Badge>
          <span className="grow text-ink-muted tabular-nums">
            {new Date(lesson.created_at).toLocaleDateString("he-IL")}
          </span>
        </div>

        {mergedCount > 0 && (
          <div className="text-[0.72rem] text-ink-muted">
            ⤷ מוזג מ-<b className="text-navy font-semibold">{mergedCount} לקחים</b> · דחייה תשחזר אותם
          </div>
        )}

        {editing ? (
          <>
            <Textarea value={text} onChange={(e) => setText(e.target.value)}
              rows={3} dir="rtl" />
            <div className="flex items-center gap-2">
              <Select value={category}
                onValueChange={(v) => setCategory(v as DecisionLesson["category"])}
                dir="rtl">
                <SelectTrigger className="w-40">
                  <SelectValue />
                </SelectTrigger>
                <SelectContent>
                  {CATEGORIES.map((c) => (
                    <SelectItem key={c.value} value={c.value}>{c.label}</SelectItem>
                  ))}
                </SelectContent>
              </Select>
              <div className="grow" />
              <Button variant="ghost" size="sm"
                onClick={() => { setEditing(false); setText(lesson.lesson_text); setCategory(lesson.category); }}>
                ביטול
              </Button>
              <Button size="sm" onClick={onSave} disabled={patch.isPending}
                className="bg-navy text-parchment hover:bg-navy-soft">
                <Save className="w-3 h-3 me-1" />
                שמור
              </Button>
            </div>
          </>
        ) : (
          <>
            <p className="text-sm text-ink leading-relaxed whitespace-pre-wrap"
               onClick={() => setEditing(true)}
               style={{ cursor: "text" }}>
              {lesson.lesson_text}
            </p>
            <div className="flex items-center gap-2">
              {/* review gate — only an approved lesson flows to the writer */}
              {lesson.review_status === "approved" ? (
                <Button variant="ghost" size="sm" onClick={() => onSetReview("proposed")}
                  disabled={patch.isPending}
                  className="text-ink-muted hover:text-ink">
                  <Undo2 className="w-3 h-3 me-1" />
                  בטל אישור
                </Button>
              ) : (
                <>
                  <Button variant="ghost" size="sm" onClick={() => onSetReview("approved")}
                    disabled={patch.isPending}
                    className="text-success hover:text-success hover:bg-success-bg">
                    <Check className="w-3 h-3 me-1" />
                    אשר
                  </Button>
                  {lesson.review_status === "rejected" ? (
                    <Button variant="ghost" size="sm" onClick={() => onSetReview("proposed")}
                      disabled={patch.isPending} className="text-ink-muted hover:text-ink">
                      <Undo2 className="w-3 h-3 me-1" />
                      שחזר
                    </Button>
                  ) : (
                    <Button variant="ghost" size="sm" onClick={() => onSetReview("rejected")}
                      disabled={patch.isPending}
                      className="text-danger hover:text-danger hover:bg-danger-bg">
                      <X className="w-3 h-3 me-1" />
                      דחה
                    </Button>
                  )}
                </>
              )}
              <Button variant="ghost" size="sm" onClick={() => setEditing(true)}>
                ערוך
              </Button>
              <div className="grow" />
              <Button variant="ghost" size="sm" onClick={onDelete}
                disabled={del.isPending}
                className="text-danger hover:text-danger hover:bg-danger-bg">
                <Trash2 className="w-3 h-3" />
              </Button>
            </div>
          </>
        )}
      </CardContent>
    </Card>
  );
}