import { NextResponse } from "next/server";
import { prisma, resolvePersona } from "@/lib/db";
import { getActiveAccountProfile } from "@/lib/account-context";
import { getOrCreateSettings } from "@/lib/user-settings";
import { optimizePost, type OptimizeMode } from "@/lib/ai/optimize-post";
import { parseProviderApiKeys } from "@/lib/ai/keys";
import { THREADS_MAX_CHARS } from "@/lib/utils";
import { trackAiTask } from "@/lib/jobs/track";

export const maxDuration = 60;

const VALID_MODES: OptimizeMode[] = ["polish", "hook", "shorter", "engaging", "custom"];

export async function POST(request: Request) {
  try {
    const body = await request.json();
    const {
      draftId,
      text,
      mode = "polish",
      instruction,
      save = false,
    } = body as {
      draftId?: string;
      text?: string;
      mode?: OptimizeMode;
      instruction?: string;
      save?: boolean;
    };

    if (!VALID_MODES.includes(mode)) {
      return NextResponse.json({ error: "無效的優化模式" }, { status: 400 });
    }

    let sourceText = text?.trim();
    let angle: string | null | undefined;
    let draftRecord = null;

    if (draftId) {
      draftRecord = await prisma.draft.findUnique({ where: { id: draftId } });
      if (!draftRecord) {
        return NextResponse.json({ error: "找不到草稿" }, { status: 404 });
      }
      sourceText = sourceText || draftRecord.text;
      angle = draftRecord.angle;
    }

    if (!sourceText) {
      return NextResponse.json({ error: "缺少貼文內容" }, { status: 400 });
    }

    if (sourceText.length > THREADS_MAX_CHARS) {
      return NextResponse.json({ error: `原文超過 ${THREADS_MAX_CHARS} 字上限` }, { status: 400 });
    }

    const settings = await getOrCreateSettings();
    const account = await getActiveAccountProfile();
    const apiKeys = parseProviderApiKeys(settings.providerApiKeys);

    const result = await trackAiTask("AI 優化貼文", () => optimizePost({
      text: sourceText,
      mode,
      instruction,
      persona: resolvePersona(settings, account),
      angle,
      aiProvider: settings.aiProvider,
      aiModel: settings.aiModel,
      apiKeys,
    }));

    if (save && draftRecord) {
      await prisma.draft.update({
        where: { id: draftRecord.id },
        data: {
          text: result.text,
          status: "EDITED",
        },
      });
    }

    return NextResponse.json({
      text: result.text,
      summary: result.summary,
      saved: save && !!draftRecord,
    });
  } catch (error) {
    const message = error instanceof Error ? error.message : "AI 優化失敗";
    return NextResponse.json({ error: message }, { status: 500 });
  }
}