import { NextRequest, NextResponse } from "next/server";
import { db, recipes, recipeIngredients, recipeSteps, recipePhotos, recipeBatchDishes, recipeSnapshots, ratings } from "@epicure/db";
import { eq, and, max, isNotNull } from "@epicure/db";
import { z } from "zod";
import { requireSessionOrApiKey } from "@/lib/api-auth";
import { checkTierLimitInTransaction, TierLimitError } from "@/lib/tiers";
import { deleteObject, isOwnedRecipePhotoKey } from "@/lib/storage";
import { dispatchWebhook } from "@/lib/webhooks";
import { parseQuantity } from "@/lib/parse-quantity";
import { extractIngredientQuantity } from "@/lib/extract-ingredient-quantity";

const UpdateRecipeSchema = z.object({
  title: z.string().min(1).max(200).optional(),
  description: z.string().max(2000).optional(),
  baseServings: z.number().int().min(1).max(100).optional(),
  recipeType: z.enum(["dish", "drink"]).optional(),
  visibility: z.enum(["private", "unlisted", "public", "followers"]).optional(),
  difficulty: z.enum(["easy", "medium", "hard"]).nullable().optional(),
  prepMins: z.number().int().min(0).max(1440).nullable().optional(),
  cookMins: z.number().int().min(0).max(1440).nullable().optional(),
  tags: z.array(z.string().min(1).max(50)).max(20).optional(),
  dietaryTags: z.object({
    vegan: z.boolean().optional(),
    vegetarian: z.boolean().optional(),
    glutenFree: z.boolean().optional(),
    dairyFree: z.boolean().optional(),
    nutFree: z.boolean().optional(),
    halal: z.boolean().optional(),
    kosher: z.boolean().optional(),
  }).optional(),
  ingredients: z.array(z.object({
    rawName: z.string().min(1).max(200),
    quantity: z.union([z.number(), z.string().max(50)]).optional().transform(parseQuantity),
    unit: z.string().max(50).optional(),
    note: z.string().max(500).optional(),
    order: z.number().int().default(0),
  }).transform((ing) => {
    const { rawName, quantity, unit } = extractIngredientQuantity(ing.rawName, ing.quantity, ing.unit);
    return { ...ing, rawName, quantity, unit };
  })).max(100).optional(),
  steps: z.array(z.object({
    instruction: z.string().min(1).max(2000),
    timerSeconds: z.number().int().min(0).max(86400).optional(),
    order: z.number().int(),
    appliesTo: z.array(z.string().min(1).max(100)).max(20).default([]),
  })).max(100).optional(),
  photos: z.array(z.object({
    key: z.string().min(1).max(500),
    isCover: z.boolean().default(false),
    sizeMb: z.number().int().min(0).max(50).default(0),
  })).max(20).optional(),
  coverIcon: z.string().max(50).nullable().optional(),
  coverColor: z.string().max(50).nullable().optional(),
  isBatchCook: z.boolean().optional(),
  dishes: z.array(z.object({
    name: z.string().min(1).max(100),
    description: z.string().max(500).optional(),
    fridgeDays: z.number().int().min(1).max(14),
    freezerFriendly: z.boolean().default(false),
    freezerNote: z.string().max(300).optional(),
    dayOfInstructions: z.string().min(1).max(1000),
  })).max(10).optional(),
  // Manually-entered per-serving nutrition — set to null to clear it and
  // re-enable the AI-estimate action on the recipe page.
  nutrition: z.object({
    calories: z.number().min(0).max(10000),
    proteinG: z.number().min(0).max(1000),
    carbsG: z.number().min(0).max(1000),
    fatG: z.number().min(0).max(1000),
    fiberG: z.number().min(0).max(1000),
    sodiumMg: z.number().min(0).max(100000),
  }).nullable().optional(),
});

type Params = { params: Promise<{ id: string }> };

async function getOwnedRecipe(recipeId: string, userId: string) {
  return db.query.recipes.findFirst({
    where: and(eq(recipes.id, recipeId), eq(recipes.authorId, userId)),
    with: {
      ingredients: { orderBy: (t, { asc }) => asc(t.order) },
      steps: { orderBy: (t, { asc }) => asc(t.order) },
      photos: true,
      batchDishes: { orderBy: (t, { asc }) => asc(t.order) },
    },
  });
}

export async function GET(req: NextRequest, { params }: Params) {
  const { session, response } = await requireSessionOrApiKey(req, { rateLimit: { limit: 60, windowSeconds: 60 } });
  if (response) return response;
  const { id } = await params;

  const recipe = await getOwnedRecipe(id, session!.user.id);
  if (!recipe) return NextResponse.json({ error: "Not found" }, { status: 404 });

  return NextResponse.json(recipe);
}

export async function PUT(req: NextRequest, { params }: Params) {
  const { session, response } = await requireSessionOrApiKey(req, { rateLimit: { limit: 60, windowSeconds: 60 } });
  if (response) return response;
  const { id } = await params;

  const existing = await db.query.recipes.findFirst({
    where: and(eq(recipes.id, id), eq(recipes.authorId, session!.user.id)),
    with: {
      ingredients: { orderBy: (t, { asc }) => asc(t.order) },
      steps: { orderBy: (t, { asc }) => asc(t.order) },
      photos: true,
      batchDishes: { orderBy: (t, { asc }) => asc(t.order) },
    },
  });
  if (!existing) return NextResponse.json({ error: "Not found" }, { status: 404 });

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

  const data = parsed.data;

  if (data.photos?.some((p) => !isOwnedRecipePhotoKey(p.key, id, session!.user.id))) {
    return NextResponse.json({ error: "Validation error", issues: [{ path: ["photos"], message: "Photo key not issued for this recipe" }] }, { status: 400 });
  }

  const photosSizeDeltaMb = data.photos !== undefined
    ? data.photos.reduce((sum, p) => sum + p.sizeMb, 0) - existing.photos.reduce((sum, p) => sum + p.sizeMb, 0)
    : 0;

  try {
    await db.transaction(async (tx) => {
    if (photosSizeDeltaMb > 0) {
      await checkTierLimitInTransaction(tx, session!.user.id, session!.user.tier as "free" | "pro" | "family", "storage", photosSizeDeltaMb);
    }
    // Create a snapshot of the current state before updating
    const [maxVersionRow] = await tx
      .select({ v: max(recipeSnapshots.version) })
      .from(recipeSnapshots)
      .where(eq(recipeSnapshots.recipeId, id));
    const nextVersion = (maxVersionRow?.v ?? 0) + 1;
    await tx.insert(recipeSnapshots).values({
      id: crypto.randomUUID(),
      recipeId: id,
      authorId: session!.user.id,
      version: nextVersion,
      title: existing.title,
      snapshotData: {
        title: existing.title,
        description: existing.description,
        baseServings: existing.baseServings,
        difficulty: existing.difficulty,
        prepMins: existing.prepMins,
        cookMins: existing.cookMins,
        dietaryTags: existing.dietaryTags ?? {},
        ingredients: existing.ingredients.map((i) => ({
          rawName: i.rawName,
          quantity: i.quantity,
          unit: i.unit,
          note: i.note,
          order: i.order,
        })),
        steps: existing.steps.map((s) => ({
          instruction: s.instruction,
          timerSeconds: s.timerSeconds,
          order: s.order,
        })),
      },
    });

    const updates: Partial<typeof recipes.$inferInsert> = { updatedAt: new Date() };
    if (data.title !== undefined) updates.title = data.title;
    if (data.description !== undefined) updates.description = data.description;
    if (data.baseServings !== undefined) updates.baseServings = data.baseServings;
    if (data.recipeType !== undefined) updates.recipeType = data.recipeType;
    if (data.visibility !== undefined) updates.visibility = data.visibility;
    if (data.difficulty !== undefined) updates.difficulty = data.difficulty ?? undefined;
    if (data.prepMins !== undefined) updates.prepMins = data.prepMins ?? undefined;
    if (data.cookMins !== undefined) updates.cookMins = data.cookMins ?? undefined;
    if (data.tags !== undefined) updates.tags = data.tags;
    if (data.dietaryTags !== undefined) updates.dietaryTags = data.dietaryTags;
    if (data.isBatchCook !== undefined) updates.isBatchCook = data.isBatchCook;
    if (data.coverIcon !== undefined) updates.coverIcon = data.coverIcon;
    if (data.coverColor !== undefined) updates.coverColor = data.coverColor;
    if (data.nutrition !== undefined) {
      updates.nutritionData = data.nutrition ? { perServing: data.nutrition } : null;
      updates.nutritionManual = !!data.nutrition;
    }

    await tx.update(recipes).set(updates).where(eq(recipes.id, id));

    if (data.ingredients !== undefined) {
      await tx.delete(recipeIngredients).where(eq(recipeIngredients.recipeId, id));
      if (data.ingredients.length > 0) {
        await tx.insert(recipeIngredients).values(
          data.ingredients.map((ing, i) => ({
            id: crypto.randomUUID(),
            recipeId: id,
            rawName: ing.rawName,
            quantity: ing.quantity,
            unit: ing.unit,
            note: ing.note,
            order: ing.order ?? i,
          }))
        );
      }
    }

    if (data.steps !== undefined) {
      await tx.delete(recipeSteps).where(eq(recipeSteps.recipeId, id));
      if (data.steps.length > 0) {
        await tx.insert(recipeSteps).values(
          data.steps.map((step, i) => ({
            id: crypto.randomUUID(),
            recipeId: id,
            instruction: step.instruction,
            timerSeconds: step.timerSeconds,
            order: step.order ?? i,
            appliesTo: step.appliesTo,
          }))
        );
      }
    }

    if (data.dishes !== undefined) {
      await tx.delete(recipeBatchDishes).where(eq(recipeBatchDishes.recipeId, id));
      if (data.dishes.length > 0) {
        await tx.insert(recipeBatchDishes).values(
          data.dishes.map((dish, i) => ({
            id: crypto.randomUUID(),
            recipeId: id,
            name: dish.name,
            description: dish.description,
            order: i,
            fridgeDays: dish.fridgeDays,
            freezerFriendly: dish.freezerFriendly,
            freezerNote: dish.freezerNote,
            dayOfInstructions: dish.dayOfInstructions,
          }))
        );
      }
    }

    if (data.photos !== undefined) {
      await tx.delete(recipePhotos).where(eq(recipePhotos.recipeId, id));
      if (data.photos.length > 0) {
        await tx.insert(recipePhotos).values(
          data.photos.map((photo, i) => ({
            id: crypto.randomUUID(),
            recipeId: id,
            storageKey: photo.key,
            order: i,
            isCover: photo.isCover,
            sizeMb: photo.sizeMb,
          }))
        );
      }
    }
    });
  } catch (err) {
    if (err instanceof TierLimitError) {
      return NextResponse.json({ error: "Storage limit reached for your tier" }, { status: 403 });
    }
    throw err;
  }

  if (data.photos !== undefined) {
    const newKeys = new Set(data.photos.map((p) => p.key));
    const removedKeys = existing.photos.filter((p) => !newKeys.has(p.storageKey)).map((p) => p.storageKey);
    await Promise.all(removedKeys.map((key) => deleteObject(key).catch(() => {})));
  }

  const updated = await getOwnedRecipe(id, session!.user.id);
  void dispatchWebhook(session!.user.id, "recipe.updated", { id, title: updated?.title });
  if (existing.visibility === "private" && data.visibility === "public") {
    void dispatchWebhook(session!.user.id, "recipe.published", { id, title: updated?.title });
  }
  return NextResponse.json(updated);
}

export async function DELETE(req: NextRequest, { params }: Params) {
  const { session, response } = await requireSessionOrApiKey(req, { rateLimit: { limit: 60, windowSeconds: 60 } });
  if (response) return response;
  const { id } = await params;

  const existing = await db.query.recipes.findFirst({
    where: and(eq(recipes.id, id), eq(recipes.authorId, session!.user.id)),
    with: { photos: true },
  });
  if (!existing) return NextResponse.json({ error: "Not found" }, { status: 404 });

  // Collect storage keys before the cascade delete removes the rows.
  // recipeSteps.photoUrl stores a full URL rather than a storage key, so it
  // is intentionally not deleted here — only objects this app stored by key.
  const reviewPhotos = await db
    .select({ photoKey: ratings.photoKey })
    .from(ratings)
    .where(and(eq(ratings.recipeId, id), isNotNull(ratings.photoKey)));
  const storageKeys = [
    ...existing.photos.map((p) => p.storageKey),
    ...reviewPhotos.map((r) => r.photoKey).filter((k): k is string => k !== null),
  ];

  await db.delete(recipes).where(eq(recipes.id, id));

  // Best-effort object cleanup: a storage failure must not fail the response.
  for (const key of storageKeys) {
    try {
      await deleteObject(key);
    } catch (err) {
      console.error(`Failed to delete storage object ${key} for recipe ${id}`, err);
    }
  }

  void dispatchWebhook(session!.user.id, "recipe.deleted", { id });
  return new NextResponse(null, { status: 204 });
}