import { NextRequest, NextResponse } from "next/server";
import { z } from "zod";
import { requireSession } from "@/lib/api-auth";
import { applyRateLimit } from "@/lib/rate-limit";
import { withAiQuota } from "@/lib/ai/ai-error";
import { generateRecipe } from "@/lib/ai/features/generate-recipe";
import { getUserPrivateBio } from "@/lib/ai/user-bio";
import { db, recipes, recipeIngredients, recipeSteps } from "@epicure/db";
import { parseQuantity } from "@/lib/parse-quantity";

const Schema = z.object({
  title: z.string().min(1).max(200),
  provider: z.enum(["openai", "anthropic", "openrouter", "ollama"]).optional(),
  model: z.string().optional(),
});

const LANG: Record<string, string> = { en: "English", fr: "French" };

export async function POST(req: NextRequest) {
  const { session, response } = await requireSession();
  if (response) return response;

  const body = await req.json() as unknown;
  const parsed = Schema.safeParse(body);
  if (!parsed.success) {
    return NextResponse.json({ error: "Validation error" }, { status: 400 });
  }

  const limited = await applyRateLimit(`rl:ai:${session!.user.id}`, 10, 60);
  if (limited) return limited;

  const privateBio = await getUserPrivateBio(session!.user.id);
  const locale = (session!.user as { locale?: string }).locale ?? "en";

  const result = await withAiQuota(session!.user.id, session!.user.tier as "free" | "pro", () =>
    generateRecipe(parsed.data.title, {
      provider: parsed.data.provider,
      model: parsed.data.model,
      userContext: privateBio ?? undefined,
      language: LANG[locale] ?? "English",
    })
  );
  if (!result.ok) return result.response;
  const recipe = result.data;

  const recipeId = crypto.randomUUID();

  await db.insert(recipes).values({
    id: recipeId,
    authorId: session!.user.id,
    title: recipe.title,
    description: recipe.description ?? null,
    baseServings: recipe.baseServings,
    prepMins: recipe.prepMins ?? null,
    cookMins: recipe.cookMins ?? null,
    difficulty: recipe.difficulty ?? null,
    visibility: "private",
    aiGenerated: true,
    language: locale,
    dietaryTags: recipe.dietaryTags ?? {},
    tags: [],
  });

  if (recipe.ingredients?.length) {
    await db.insert(recipeIngredients).values(
      recipe.ingredients.map((ing, i) => ({
        id: crypto.randomUUID(),
        recipeId,
        rawName: ing.rawName,
        quantity: parseQuantity(ing.quantity) ?? null,
        unit: ing.unit ?? null,
        note: ing.note ?? null,
        order: i,
      }))
    );
  }

  if (recipe.steps?.length) {
    await db.insert(recipeSteps).values(
      recipe.steps.map((step, i) => ({
        id: crypto.randomUUID(),
        recipeId,
        instruction: step.instruction,
        timerSeconds: step.timerSeconds ?? null,
        order: i,
      }))
    );
  }

  return NextResponse.json({ id: recipeId });
}