"use client";

import React from "react";
import { ArrowRight, Link2, Unlink2, Plus, Trash2, Pencil, X } from "lucide-react";
import { Button } from "@/components/ui/button";
import { Label } from "@/components/ui/label";
import {
  Select,
  SelectContent,
  SelectItem,
  SelectTrigger,
  SelectValue,
} from "@/components/ui/select";
import {
  PopComponentDefinitionV5,
  PopDataConnection,
} from "../types/pop-layout";
import {
  PopComponentRegistry,
} from "@/lib/registry/PopComponentRegistry";

// ========================================
// Props
// ========================================

interface ConnectionEditorProps {
  component: PopComponentDefinitionV5;
  allComponents: PopComponentDefinitionV5[];
  connections: PopDataConnection[];
  onAddConnection?: (conn: Omit<PopDataConnection, "id">) => void;
  onUpdateConnection?: (connectionId: string, conn: Omit<PopDataConnection, "id">) => void;
  onRemoveConnection?: (connectionId: string) => void;
}

// ========================================
// ConnectionEditor
// ========================================

export default function ConnectionEditor({
  component,
  allComponents,
  connections,
  onAddConnection,
  onUpdateConnection,
  onRemoveConnection,
}: ConnectionEditorProps) {
  const registeredComp = PopComponentRegistry.getComponent(component.type);
  const meta = registeredComp?.connectionMeta;

  const outgoing = connections.filter(
    (c) => c.sourceComponent === component.id
  );
  const incoming = connections.filter(
    (c) => c.targetComponent === component.id
  );

  const hasSendable = meta?.sendable && meta.sendable.length > 0;
  const hasReceivable = meta?.receivable && meta.receivable.length > 0;

  if (!hasSendable && !hasReceivable) {
    return (
      <div className="space-y-4">
        <div className="rounded-lg bg-gray-50 p-4 text-center">
          <Link2 className="mx-auto mb-2 h-8 w-8 text-muted-foreground" />
          <p className="text-sm font-medium text-gray-700">연결 없음</p>
          <p className="mt-1 text-xs text-muted-foreground">
            이 컴포넌트는 다른 컴포넌트와 연결할 수 없습니다
          </p>
        </div>
      </div>
    );
  }

  return (
    <div className="space-y-6">
      {hasSendable && (
        <SendSection
          component={component}
          allComponents={allComponents}
          outgoing={outgoing}
          onAddConnection={onAddConnection}
          onUpdateConnection={onUpdateConnection}
          onRemoveConnection={onRemoveConnection}
        />
      )}

      {hasReceivable && (
        <ReceiveSection
          component={component}
          allComponents={allComponents}
          incoming={incoming}
        />
      )}
    </div>
  );
}

// ========================================
// 보내기 섹션
// ========================================

interface SendSectionProps {
  component: PopComponentDefinitionV5;
  allComponents: PopComponentDefinitionV5[];
  outgoing: PopDataConnection[];
  onAddConnection?: (conn: Omit<PopDataConnection, "id">) => void;
  onUpdateConnection?: (connectionId: string, conn: Omit<PopDataConnection, "id">) => void;
  onRemoveConnection?: (connectionId: string) => void;
}

function SendSection({
  component,
  allComponents,
  outgoing,
  onAddConnection,
  onUpdateConnection,
  onRemoveConnection,
}: SendSectionProps) {
  const [editingId, setEditingId] = React.useState<string | null>(null);

  return (
    <div className="space-y-3">
      <Label className="flex items-center gap-1 text-xs font-medium">
        <ArrowRight className="h-3 w-3 text-blue-500" />
        보내기
      </Label>

      {outgoing.map((conn) => (
        <div key={conn.id}>
          {editingId === conn.id ? (
            <SimpleConnectionForm
              component={component}
              allComponents={allComponents}
              initial={conn}
              onSubmit={(data) => {
                onUpdateConnection?.(conn.id, data);
                setEditingId(null);
              }}
              onCancel={() => setEditingId(null)}
              submitLabel="수정"
            />
          ) : (
            <div className="flex items-center gap-1 rounded border bg-blue-50/50 px-3 py-2">
              <span className="flex-1 truncate text-xs">
                {conn.label || `→ ${allComponents.find((c) => c.id === conn.targetComponent)?.label || conn.targetComponent}`}
              </span>
              <button
                onClick={() => setEditingId(conn.id)}
                className="shrink-0 p-0.5 text-muted-foreground hover:text-primary"
              >
                <Pencil className="h-3 w-3" />
              </button>
              {onRemoveConnection && (
                <button
                  onClick={() => onRemoveConnection(conn.id)}
                  className="shrink-0 p-0.5 text-muted-foreground hover:text-destructive"
                >
                  <Trash2 className="h-3 w-3" />
                </button>
              )}
            </div>
          )}
        </div>
      ))}

      <SimpleConnectionForm
        component={component}
        allComponents={allComponents}
        onSubmit={(data) => onAddConnection?.(data)}
        submitLabel="연결 추가"
      />
    </div>
  );
}

// ========================================
// 단순 연결 폼 (이벤트 타입: "어디로" 1개만)
// ========================================

interface SimpleConnectionFormProps {
  component: PopComponentDefinitionV5;
  allComponents: PopComponentDefinitionV5[];
  initial?: PopDataConnection;
  onSubmit: (data: Omit<PopDataConnection, "id">) => void;
  onCancel?: () => void;
  submitLabel: string;
}

function SimpleConnectionForm({
  component,
  allComponents,
  initial,
  onSubmit,
  onCancel,
  submitLabel,
}: SimpleConnectionFormProps) {
  const [selectedTargetId, setSelectedTargetId] = React.useState(
    initial?.targetComponent || ""
  );

  const targetCandidates = allComponents.filter((c) => {
    if (c.id === component.id) return false;
    const reg = PopComponentRegistry.getComponent(c.type);
    return reg?.connectionMeta?.receivable && reg.connectionMeta.receivable.length > 0;
  });

  const handleSubmit = () => {
    if (!selectedTargetId) return;

    const targetComp = allComponents.find((c) => c.id === selectedTargetId);
    const srcLabel = component.label || component.id;
    const tgtLabel = targetComp?.label || targetComp?.id || "?";

    onSubmit({
      sourceComponent: component.id,
      sourceField: "",
      sourceOutput: "_auto",
      targetComponent: selectedTargetId,
      targetField: "",
      targetInput: "_auto",
      label: `${srcLabel} → ${tgtLabel}`,
    });

    if (!initial) {
      setSelectedTargetId("");
    }
  };

  return (
    <div className="space-y-2 rounded border border-dashed p-3">
      {onCancel && (
        <div className="flex items-center justify-between">
          <p className="text-[10px] font-medium text-muted-foreground">연결 수정</p>
          <button onClick={onCancel} className="text-muted-foreground hover:text-foreground">
            <X className="h-3 w-3" />
          </button>
        </div>
      )}
      {!onCancel && (
        <p className="text-[10px] font-medium text-muted-foreground">새 연결 추가</p>
      )}

      <div className="space-y-1">
        <span className="text-[10px] text-muted-foreground">어디로?</span>
        <Select
          value={selectedTargetId}
          onValueChange={setSelectedTargetId}
        >
          <SelectTrigger className="h-7 text-xs">
            <SelectValue placeholder="컴포넌트 선택" />
          </SelectTrigger>
          <SelectContent>
            {targetCandidates.map((c) => (
              <SelectItem key={c.id} value={c.id} className="text-xs">
                {c.label || c.id}
              </SelectItem>
            ))}
          </SelectContent>
        </Select>
      </div>

      <Button
        size="sm"
        variant="outline"
        className="h-7 w-full text-xs"
        disabled={!selectedTargetId}
        onClick={handleSubmit}
      >
        {!initial && <Plus className="mr-1 h-3 w-3" />}
        {submitLabel}
      </Button>
    </div>
  );
}

// ========================================
// 받기 섹션 (읽기 전용: 연결된 소스만 표시)
// ========================================

interface ReceiveSectionProps {
  component: PopComponentDefinitionV5;
  allComponents: PopComponentDefinitionV5[];
  incoming: PopDataConnection[];
}

function ReceiveSection({
  component,
  allComponents,
  incoming,
}: ReceiveSectionProps) {
  return (
    <div className="space-y-3">
      <Label className="flex items-center gap-1 text-xs font-medium">
        <Unlink2 className="h-3 w-3 text-green-500" />
        받기
      </Label>

      {incoming.length > 0 ? (
        <div className="space-y-1">
          {incoming.map((conn) => {
            const sourceComp = allComponents.find(
              (c) => c.id === conn.sourceComponent
            );
            return (
              <div
                key={conn.id}
                className="flex items-center gap-2 rounded border bg-green-50/50 px-3 py-2 text-xs"
              >
                <ArrowRight className="h-3 w-3 text-green-500" />
                <span className="truncate">
                  {sourceComp?.label || conn.sourceComponent}
                </span>
              </div>
            );
          })}
        </div>
      ) : (
        <p className="text-xs text-muted-foreground">
          연결된 소스가 없습니다
        </p>
      )}
    </div>
  );
}