import { Elysia, t } from "elysia";
import prisma from "../lib/prisma";
import {
  SUPPORTED_LANGS,
  localizeAttributeDefinition,
  localizeProductAttribute,
  normalizeAttributeType,
  validateAttributeValue,
  validateSelectOption,
} from "../lib/productAttributes";

function parseId(value: string, label: string) {
  const parsed = parseInt(value);
  if (Number.isNaN(parsed)) {
    throw new Error(`Invalid ${label}`);
  }
  return parsed;
}

function buildDefinitionPayload(payload: any) {
  return {
    code: payload.code,
    label: payload.label,
    description: payload.description ?? null,
    type: normalizeAttributeType(payload.type),
    unit: payload.unit ?? null,
    options: payload.options ?? null,
    isRequired: Boolean(payload.isRequired),
    isFilterable: Boolean(payload.isFilterable),
    sortOrder: typeof payload.sortOrder === 'number' ? payload.sortOrder : 0,
    categoryId: payload.categoryId ?? null,
  };
}

async function assertProductAndDefinitionMatch(productId: number, attributeDefinitionId: number) {
  const [product, definition] = await Promise.all([
    prisma.product.findUnique({ where: { id: productId } }),
    prisma.attributeDefinition.findUnique({ where: { id: attributeDefinitionId } }),
  ]);

  if (!product) throw new Error("Product not found");
  if (!definition) throw new Error("Attribute definition not found");
  if (definition.categoryId && definition.categoryId !== product.categoryId) {
    throw new Error("Attribute definition category does not match product category");
  }

  return { product, definition };
}

export const productAttributesRoute = new Elysia()
  .get("/product-attributes/definitions", async ({ query }) => {
    const lang = (query as any).lang || 'th';
    const categoryId = (query as any).categoryId ? parseInt((query as any).categoryId) : undefined;

    const definitions = await prisma.attributeDefinition.findMany({
      where: categoryId ? { OR: [{ categoryId }, { categoryId: null }] } : undefined,
      include: {
        category: true,
        translations: true,
      },
      orderBy: [
        { sortOrder: 'asc' },
        { code: 'asc' },
      ],
    });

    return definitions.map((definition: any) => localizeAttributeDefinition(definition, lang));
  })
  .get("/product-attributes/definitions/:id", async ({ params, query, status }) => {
    try {
      const id = parseId(params.id, "attribute definition ID");
      const lang = (query as any).lang || 'th';
      const definition = await prisma.attributeDefinition.findUnique({
        where: { id },
        include: {
          category: true,
          translations: true,
        },
      });

      if (!definition) return status(404, { message: "Attribute definition not found" });
      return localizeAttributeDefinition(definition, lang);
    } catch (err: any) {
      return status(400, { message: err.message });
    }
  })
  .post("/product-attributes/definitions", async ({ body, status }) => {
    try {
      const payload = body as any;
      const definition = await prisma.attributeDefinition.create({
        data: {
          ...buildDefinitionPayload(payload),
          translations: payload.translations && typeof payload.translations === 'object'
            ? {
                create: Object.entries(payload.translations)
                  .filter(([lang, value]) => SUPPORTED_LANGS.includes(lang as any) && value && typeof value === 'object' && (value as any).label)
                  .map(([lang, value]) => ({
                    langCode: lang,
                    label: (value as any).label,
                    description: (value as any).description ?? null,
                  })),
              }
            : undefined,
        },
        include: {
          category: true,
          translations: true,
        },
      });

      return { success: true, definition };
    } catch (err: any) {
      if (err.code === 'P2002') return status(400, { message: "Attribute definition code already exists" });
      return status(500, { message: err?.message || "Failed to create attribute definition" });
    }
  }, {
    body: t.Any(),
  })
  .put("/product-attributes/definitions/:id", async ({ params, body, status }) => {
    try {
      const id = parseId(params.id, "attribute definition ID");
      const payload = body as any;
      const definition = await prisma.attributeDefinition.update({
        where: { id },
        data: buildDefinitionPayload(payload),
        include: {
          category: true,
          translations: true,
        },
      });

      return { success: true, definition };
    } catch (err: any) {
      if (err.code === 'P2025') return status(404, { message: "Attribute definition not found" });
      if (err.code === 'P2002') return status(400, { message: "Attribute definition code already exists" });
      return status(500, { message: err?.message || "Failed to update attribute definition" });
    }
  }, {
    body: t.Any(),
  })
  .patch("/product-attributes/definitions/:id/translations", async ({ params, body, status }) => {
    try {
      const id = parseId(params.id, "attribute definition ID");
      const definition = await prisma.attributeDefinition.findUnique({ where: { id } });
      if (!definition) return status(404, { message: "Attribute definition not found" });

      const payload = body as any;
      const results: any[] = [];

      for (const lang of SUPPORTED_LANGS) {
        const item = payload.translations?.[lang]
          || ((payload.label?.[lang] || payload.description?.[lang]) ? { label: payload.label?.[lang], description: payload.description?.[lang] } : null);

        if (!item?.label) continue;

        const existing = await prisma.attributeDefinitionTranslation.findUnique({
          where: { attributeDefinitionId_langCode: { attributeDefinitionId: id, langCode: lang } },
        });

        const data = {
          label: item.label,
          description: item.description ?? null,
        };

        if (existing) {
          results.push(await prisma.attributeDefinitionTranslation.update({
            where: { id: existing.id },
            data,
          }));
        } else {
          results.push(await prisma.attributeDefinitionTranslation.create({
            data: {
              attributeDefinitionId: id,
              langCode: lang,
              ...data,
            },
          }));
        }
      }

      if (results.length === 0) return status(400, { message: "No valid translations provided" });

      const updated = await prisma.attributeDefinition.findUnique({
        where: { id },
        include: { category: true, translations: true },
      });

      return { success: true, definition: updated, translations: results };
    } catch (err: any) {
      return status(500, { message: err?.message || "Failed to update attribute definition translations" });
    }
  }, {
    body: t.Any(),
  })
  .get("/products/:id/attributes", async ({ params, query, status }) => {
    try {
      const productId = parseId(params.id, "product ID");
      const lang = (query as any).lang || 'th';
      const product = await prisma.product.findUnique({ where: { id: productId } });
      if (!product) return status(404, { message: "Product not found" });

      const attributes = await prisma.productAttribute.findMany({
        where: { productId },
        include: {
          translations: true,
          attributeDefinition: {
            include: {
              category: true,
              translations: true,
            },
          },
        },
        orderBy: [
          { attributeDefinition: { sortOrder: 'asc' } },
          { id: 'asc' },
        ],
      });

      return attributes.map((attribute: any) => localizeProductAttribute(attribute, lang));
    } catch (err: any) {
      return status(400, { message: err.message });
    }
  })
  .post("/products/:id/attributes", async ({ params, body, status }) => {
    try {
      const productId = parseId(params.id, "product ID");
      const payload = body as any;
      const attributeDefinitionId = Number(payload.attributeDefinitionId);
      if (!attributeDefinitionId) return status(400, { message: "attributeDefinitionId is required" });

      const { definition } = await assertProductAndDefinitionMatch(productId, attributeDefinitionId);
      const type = normalizeAttributeType(definition.type);
      validateAttributeValue(type, payload);
      if (type === 'SELECT') validateSelectOption(definition.options, payload.valueText);

      const attribute = await prisma.productAttribute.upsert({
        where: { productId_attributeDefinitionId: { productId, attributeDefinitionId } },
        update: {
          valueText: payload.valueText ?? null,
          valueNumber: payload.valueNumber ?? null,
          valueBoolean: payload.valueBoolean ?? null,
          valueJson: payload.valueJson ?? null,
        },
        create: {
          productId,
          attributeDefinitionId,
          valueText: payload.valueText ?? null,
          valueNumber: payload.valueNumber ?? null,
          valueBoolean: payload.valueBoolean ?? null,
          valueJson: payload.valueJson ?? null,
        },
        include: {
          translations: true,
          attributeDefinition: { include: { category: true, translations: true } },
        },
      });

      return { success: true, attribute };
    } catch (err: any) {
      const code = err.message === "Product not found" || err.message === "Attribute definition not found" ? 404 : 400;
      return status(code, { message: err.message });
    }
  }, {
    body: t.Any(),
  })
  .put("/products/:id/attributes", async ({ params, body, status }) => {
    try {
      const productId = parseId(params.id, "product ID");
      const payload = body as any;
      if (!Array.isArray(payload.attributes)) return status(400, { message: "attributes array is required" });

      const product = await prisma.product.findUnique({ where: { id: productId } });
      if (!product) return status(404, { message: "Product not found" });

      const existing = await prisma.productAttribute.findMany({
        where: { productId },
        select: { id: true, attributeDefinitionId: true },
      });
      const incomingDefinitionIds = payload.attributes.map((item: any) => Number(item.attributeDefinitionId)).filter(Boolean);
      const toDelete = existing.filter((item: any) => !incomingDefinitionIds.includes(item.attributeDefinitionId));

      if (toDelete.length > 0) {
        await prisma.productAttribute.deleteMany({
          where: { id: { in: toDelete.map((item: any) => item.id) } },
        });
      }

      const results = [];
      for (const item of payload.attributes) {
        const attributeDefinitionId = Number(item.attributeDefinitionId);
        const { definition } = await assertProductAndDefinitionMatch(productId, attributeDefinitionId);
        const type = normalizeAttributeType(definition.type);
        validateAttributeValue(type, item);
        if (type === 'SELECT') validateSelectOption(definition.options, item.valueText);

        const attribute = await prisma.productAttribute.upsert({
          where: { productId_attributeDefinitionId: { productId, attributeDefinitionId } },
          update: {
            valueText: item.valueText ?? null,
            valueNumber: item.valueNumber ?? null,
            valueBoolean: item.valueBoolean ?? null,
            valueJson: item.valueJson ?? null,
          },
          create: {
            productId,
            attributeDefinitionId,
            valueText: item.valueText ?? null,
            valueNumber: item.valueNumber ?? null,
            valueBoolean: item.valueBoolean ?? null,
            valueJson: item.valueJson ?? null,
          },
          include: {
            translations: true,
            attributeDefinition: { include: { category: true, translations: true } },
          },
        });

        if (type === 'TEXT' && item.translations && typeof item.translations === 'object') {
          for (const lang of SUPPORTED_LANGS) {
            const translatedValue = item.translations[lang];
            if (typeof translatedValue !== 'string' || !translatedValue.trim()) continue;
            await prisma.productAttributeTranslation.upsert({
              where: { productAttributeId_langCode: { productAttributeId: attribute.id, langCode: lang } },
              update: { valueText: translatedValue },
              create: { productAttributeId: attribute.id, langCode: lang, valueText: translatedValue },
            });
          }
        }

        results.push(attribute);
      }

      const updated = await prisma.productAttribute.findMany({
        where: { productId },
        include: {
          translations: true,
          attributeDefinition: { include: { category: true, translations: true } },
        },
        orderBy: [
          { attributeDefinition: { sortOrder: 'asc' } },
          { id: 'asc' },
        ],
      });

      return { success: true, attributes: updated };
    } catch (err: any) {
      const code = err.message === "Product not found" || err.message === "Attribute definition not found" ? 404 : 400;
      return status(code, { message: err.message });
    }
  }, {
    body: t.Any(),
  })
  .put("/products/:id/attributes/:productAttributeId", async ({ params, body, status }) => {
    try {
      const productId = parseId(params.id, "product ID");
      const productAttributeId = parseId(params.productAttributeId, "product attribute ID");
      const attribute = await prisma.productAttribute.findUnique({
        where: { id: productAttributeId },
        include: { attributeDefinition: true },
      });

      if (!attribute || attribute.productId !== productId) {
        return status(404, { message: "Product attribute not found" });
      }

      const type = normalizeAttributeType(attribute.attributeDefinition.type);
      const payload = body as any;
      validateAttributeValue(type, payload);
      if (type === 'SELECT') validateSelectOption(attribute.attributeDefinition.options, payload.valueText);

      const updated = await prisma.productAttribute.update({
        where: { id: productAttributeId },
        data: {
          valueText: payload.valueText ?? null,
          valueNumber: payload.valueNumber ?? null,
          valueBoolean: payload.valueBoolean ?? null,
          valueJson: payload.valueJson ?? null,
        },
        include: {
          translations: true,
          attributeDefinition: { include: { category: true, translations: true } },
        },
      });

      return { success: true, attribute: updated };
    } catch (err: any) {
      return status(400, { message: err.message });
    }
  }, {
    body: t.Any(),
  })
  .patch("/products/:id/attributes/:productAttributeId/translations", async ({ params, body, status }) => {
    try {
      const productId = parseId(params.id, "product ID");
      const productAttributeId = parseId(params.productAttributeId, "product attribute ID");
      const attribute = await prisma.productAttribute.findUnique({
        where: { id: productAttributeId },
        include: { attributeDefinition: true, translations: true },
      });

      if (!attribute || attribute.productId !== productId) {
        return status(404, { message: "Product attribute not found" });
      }

      const type = normalizeAttributeType(attribute.attributeDefinition.type);
      if (type !== 'TEXT') {
        return status(400, { message: "Only TEXT product attributes support translations in this phase" });
      }

      const payload = body as any;
      const results: any[] = [];
      for (const lang of SUPPORTED_LANGS) {
        const valueText = payload.translations?.[lang] ?? payload.valueText?.[lang];
        if (typeof valueText !== 'string' || !valueText.trim()) continue;

        results.push(await prisma.productAttributeTranslation.upsert({
          where: { productAttributeId_langCode: { productAttributeId, langCode: lang } },
          update: { valueText },
          create: { productAttributeId, langCode: lang, valueText },
        }));
      }

      if (results.length === 0) return status(400, { message: "No valid translations provided" });

      const updated = await prisma.productAttribute.findUnique({
        where: { id: productAttributeId },
        include: {
          translations: true,
          attributeDefinition: { include: { category: true, translations: true } },
        },
      });

      return { success: true, attribute: updated, translations: results };
    } catch (err: any) {
      return status(400, { message: err.message });
    }
  }, {
    body: t.Any(),
  });