import * as db from '../../db/articlesupplier.js';
import { emit } from '../sse.js';

function requireSelectedCompany(req) {
    const companyId = req.user?.selectedCompanyId;
    if (companyId == null) {
        return { error: 'No company selected' };
    }
    return { companyId };
}

function parseSku(value) {
    const sku = typeof value === 'string' ? value.trim() : '';
    if (!sku) return { error: 'sku is required' };
    return { sku: decodeURIComponent(sku) };
}

function parsePositiveInt(value, field) {
    const id = Number(value);
    if (!Number.isInteger(id) || id <= 0) {
        return { error: `${field} is required` };
    }
    return { id };
}

function emitArticleSignal(req, sku) {
    const companyId = req.user?.selectedCompanyId;
    if (companyId == null) return;
    emit(`article-${sku}`, { companyId });
}

function articleSupplierErrorStatus(error) {
    if (error.message === 'No company selected') return 400;
    if (error.message === 'Not authorized') return 403;
    if (error.message === 'Company not found') return 404;
    if (error.message === 'Article not found') return 404;
    if (error.message === 'Supplier not found') return 404;
    if (error.message === 'Invalid supplierId') return 400;
    if (error.message === 'Supplier assignment not found') return 404;
    if (error.message === 'Supplier already assigned') return 409;
    if (error.message === 'Supplier required' || error.message === 'entityId is required') return 400;
    if (error.message === 'Invalid pu' || error.message === 'pu must be greater than 0') return 400;
    if (error.message === 'Invalid stock') return 400;
    if (error.message === 'Invalid sort') return 400;
    if (error.message === 'Invalid supplier order') return 400;
    if (error.message === 'Invalid price') return 400;
    if (error.message === 'sku is required') return 400;
    if (error.message === 'id is required') return 400;
    if (error.message === 'ids is required') return 400;
    return 500;
}

/**
 * Registers article supplier routes under `/article/:sku/supplier`.
 * @param {import('express').Application} app
 * @param {string} [basePath='']
 */
export function register(app, basePath = '') {
    /**
     * @openapi
     * /article/{sku}/supplier:
     *   get:
     *     tags: [Article]
     *     summary: List article suppliers
     *     description: Fetches all suppliers linked to the specified article SKU.
     *     security:
     *       - cookieAuth: []
     *     x-markdown: article/supplier/list.md
     *     parameters:
     *       - in: path
     *         name: sku
     *         required: true
     *         schema:
     *           type: string
     *         description: Article SKU
     *     responses:
     *       200:
     *         description: List of suppliers linked to the article
     *         content:
     *           application/json:
     *             schema:
     *               type: object
     *               properties:
     *                 suppliers:
     *                   type: array
     *                   items:
     *                     $ref: '#/components/schemas/ArticleSupplier'
     *       400:
     *         description: No company selected or invalid sku
     *         content:
     *           application/json:
     *             schema:
     *               $ref: '#/components/schemas/Error'
     *       401:
     *         description: Unauthorized
     *         content:
     *           application/json:
     *             schema:
     *               $ref: '#/components/schemas/Error'
     *       403:
     *         description: Not authorized
     *         content:
     *           application/json:
     *             schema:
     *               $ref: '#/components/schemas/Error'
     *       404:
     *         description: Article or company not found
     *         content:
     *           application/json:
     *             schema:
     *               $ref: '#/components/schemas/Error'
     *   post:
     *     tags: [Article]
     *     summary: Assign supplier to article
     *     description: |
     *       Assigns a supplier to an article with optional purchase price, stock, and supplier SKU.
     *     security:
     *       - cookieAuth: []
     *     x-signals: [article-<sku>]
     *     x-markdown: article/supplier/create.md
     *     parameters:
     *       - in: path
     *         name: sku
     *         required: true
     *         schema:
     *           type: string
     *         description: Article SKU
     *     requestBody:
     *       required: true
     *       content:
     *         application/json:
     *           schema:
     *             type: object
     *             required: [entityId]
     *             properties:
     *               entityId:
     *                 type: integer
     *                 description: Supplier entity ID (in Lieferanten group)
     *               sku:
     *                 type: string
     *                 nullable: true
     *                 description: Supplier's item number
     *               pu:
     *                 type: number
     *                 default: 1
     *                 description: Packaging unit (VPE)
     *               stock:
     *                 type: number
     *                 nullable: true
     *                 description: Supplier stock
     *               sort:
     *                 type: integer
     *                 nullable: true
     *                 description: Display sort order (defaults to next sort)
     *               netPrice:
     *                 type: number
     *                 nullable: true
     *                 description: Net purchase price
     *               taxId:
     *                 type: integer
     *                 nullable: true
     *                 description: Tax ID for purchase price
     *               taxRate:
     *                 type: number
     *                 nullable: true
     *                 description: Tax rate in percent
     *             example:
     *               entityId: 88
     *               sku: MET-44910
     *               pu: 1
     *               stock: 140
     *               sort: 0
     *               netPrice: 4.20
     *               taxId: 1
     *     responses:
     *       201:
     *         description: Created supplier assignment
     *         content:
     *           application/json:
     *             schema:
     *               type: object
     *               properties:
     *                 supplier:
     *                   $ref: '#/components/schemas/ArticleSupplier'
     *       400:
     *         description: entityId required, invalid pu, invalid stock, invalid price, or no company selected
     *         content:
     *           application/json:
     *             schema:
     *               $ref: '#/components/schemas/Error'
     *       401:
     *         description: Unauthorized
     *         content:
     *           application/json:
     *             schema:
     *               $ref: '#/components/schemas/Error'
     *       403:
     *         description: Not authorized
     *         content:
     *           application/json:
     *             schema:
     *               $ref: '#/components/schemas/Error'
     *       404:
     *         description: Article, supplier, or company not found
     *         content:
     *           application/json:
     *             schema:
     *               $ref: '#/components/schemas/Error'
     *       409:
     *         description: Supplier already assigned
     *         content:
     *           application/json:
     *             schema:
     *               $ref: '#/components/schemas/Error'
     */
    app.get(`${basePath}/article/:sku/supplier`, async (req, res) => {
        const selected = requireSelectedCompany(req);
        if (selected.error) {
            return res.status(400).json({ error: selected.error });
        }

        const skuParsed = parseSku(req.params.sku);
        if (skuParsed.error) {
            return res.status(400).json({ error: skuParsed.error });
        }

        try {
            const suppliers = await db.listByArticleSku(req.user.id, skuParsed.sku);
            res.status(200).json({ suppliers });
        } catch (error) {
            const status = articleSupplierErrorStatus(error);
            if (status === 500) console.error('List article suppliers failed:', error);
            res.status(status).json({ error: error.message });
        }
    });

    app.post(`${basePath}/article/:sku/supplier`, async (req, res) => {
        const selected = requireSelectedCompany(req);
        if (selected.error) {
            return res.status(400).json({ error: selected.error });
        }

        const skuParsed = parseSku(req.params.sku);
        if (skuParsed.error) {
            return res.status(400).json({ error: skuParsed.error });
        }

        const { entityId, sku: supplierSku, pu, stock, sort, netPrice, taxId, taxRate } = req.body ?? {};
        if (entityId == null) {
            return res.status(400).json({ error: 'entityId is required' });
        }
        if (typeof entityId !== 'number' || !Number.isInteger(entityId) || entityId <= 0) {
            return res.status(400).json({ error: 'entityId must be an integer' });
        }
        if (pu !== undefined && pu !== null && (typeof pu !== 'number' || !Number.isFinite(pu) || pu <= 0)) {
            return res.status(400).json({ error: 'pu must be greater than 0' });
        }
        if (stock !== undefined && stock !== null && (typeof stock !== 'number' || !Number.isFinite(stock))) {
            return res.status(400).json({ error: 'Invalid stock' });
        }
        if (sort !== undefined && sort !== null && (typeof sort !== 'number' || !Number.isInteger(sort) || sort < 0)) {
            return res.status(400).json({ error: 'Invalid sort' });
        }
        if (netPrice !== undefined && netPrice !== null && (typeof netPrice !== 'number' || !Number.isFinite(netPrice) || netPrice < 0)) {
            return res.status(400).json({ error: 'Invalid price' });
        }
        if (taxId !== undefined && taxId !== null && (typeof taxId !== 'number' || !Number.isInteger(taxId) || taxId <= 0)) {
            return res.status(400).json({ error: 'Invalid taxId' });
        }
        if (taxRate !== undefined && taxRate !== null && (typeof taxRate !== 'number' || !Number.isFinite(taxRate) || taxRate < 0)) {
            return res.status(400).json({ error: 'Invalid taxRate' });
        }

        try {
            const supplier = await db.create(req.user.id, skuParsed.sku, {
                entityId,
                sku: supplierSku,
                pu,
                stock,
                sort,
                netPrice,
                taxId,
                taxRate,
            });
            emitArticleSignal(req, skuParsed.sku);
            res.status(201).json({ supplier });
        } catch (error) {
            const status = articleSupplierErrorStatus(error);
            if (status === 500) console.error('Create article supplier failed:', error);
            res.status(status).json({ error: error.message });
        }
    });

    /**
     * @openapi
     * /article/{sku}/supplier/{id}:
     *   patch:
     *     tags: [Article]
     *     summary: Update article supplier assignment
     *     description: |
     *       Updates an existing article-supplier association (supplier SKU, packaging unit, stock, purchase price).
     *     security:
     *       - cookieAuth: []
     *     x-signals: [article-<sku>]
     *     x-markdown: article/supplier/update.md
     *     parameters:
     *       - in: path
     *         name: sku
     *         required: true
     *         schema:
     *           type: string
     *         description: Article SKU
     *       - in: path
     *         name: id
     *         required: true
     *         schema:
     *           type: integer
     *         description: articlesupplier assignment ID
     *     requestBody:
     *       required: true
     *       content:
     *         application/json:
     *           schema:
     *             type: object
     *             properties:
     *               sku:
     *                 type: string
     *                 nullable: true
     *               pu:
     *                 type: number
     *               stock:
     *                 type: number
     *                 nullable: true
     *               sort:
     *                 type: integer
     *                 description: Display sort order
     *               netPrice:
     *                 type: number
     *                 nullable: true
     *               taxId:
     *                 type: integer
     *                 nullable: true
     *               taxRate:
     *                 type: number
     *                 nullable: true
     *             example:
     *               sku: MET-44910-B
     *               pu: 6
     *               stock: 95
     *               netPrice: 22.50
     *     responses:
     *       200:
     *         description: Updated supplier assignment
     *         content:
     *           application/json:
     *             schema:
     *               type: object
     *               properties:
     *                 supplier:
     *                   $ref: '#/components/schemas/ArticleSupplier'
     *       400:
     *         description: Invalid pu, invalid stock, invalid price, invalid id, or no company selected
     *         content:
     *           application/json:
     *             schema:
     *               $ref: '#/components/schemas/Error'
     *       401:
     *         description: Unauthorized
     *         content:
     *           application/json:
     *             schema:
     *               $ref: '#/components/schemas/Error'
     *       403:
     *         description: Not authorized
     *         content:
     *           application/json:
     *             schema:
     *               $ref: '#/components/schemas/Error'
     *       404:
     *         description: Supplier assignment, article, or company not found
     *         content:
     *           application/json:
     *             schema:
     *               $ref: '#/components/schemas/Error'
     *   delete:
     *     tags: [Article]
     *     summary: Remove supplier assignment from article
     *     description: |
     *       Removes a supplier assignment from the article and cleans up its associated purchase price.
     *     security:
     *       - cookieAuth: []
     *     x-signals: [article-<sku>]
     *     x-markdown: article/supplier/delete.md
     *     parameters:
     *       - in: path
     *         name: sku
     *         required: true
     *         schema:
     *           type: string
     *         description: Article SKU
     *       - in: path
     *         name: id
     *         required: true
     *         schema:
     *           type: integer
     *         description: articlesupplier assignment ID
     *     responses:
     *       204:
     *         description: Deleted
     *       400:
     *         description: Invalid id, invalid sku, or no company selected
     *         content:
     *           application/json:
     *             schema:
     *               $ref: '#/components/schemas/Error'
     *       401:
     *         description: Unauthorized
     *         content:
     *           application/json:
     *             schema:
     *               $ref: '#/components/schemas/Error'
     *       403:
     *         description: Not authorized
     *         content:
     *           application/json:
     *             schema:
     *               $ref: '#/components/schemas/Error'
     *       404:
     *         description: Supplier assignment or article not found
     *         content:
     *           application/json:
     *             schema:
     *               $ref: '#/components/schemas/Error'
     */
    app.patch(`${basePath}/article/:sku/supplier/:id`, async (req, res) => {
        const selected = requireSelectedCompany(req);
        if (selected.error) {
            return res.status(400).json({ error: selected.error });
        }

        const skuParsed = parseSku(req.params.sku);
        if (skuParsed.error) {
            return res.status(400).json({ error: skuParsed.error });
        }

        const idParsed = parsePositiveInt(req.params.id, 'id');
        if (idParsed.error) {
            return res.status(400).json({ error: idParsed.error });
        }

        const body = req.body ?? {};
        const patch = {};
        if (body.sku !== undefined) patch.sku = body.sku;
        if (body.pu !== undefined) {
            if (body.pu === null || !Number.isFinite(body.pu) || body.pu <= 0) {
                return res.status(400).json({ error: 'pu must be greater than 0' });
            }
            patch.pu = body.pu;
        }
        if (body.stock !== undefined) {
            if (body.stock !== null && !Number.isFinite(body.stock)) {
                return res.status(400).json({ error: 'Invalid stock' });
            }
            patch.stock = body.stock;
        }
        if (body.sort !== undefined) {
            if (body.sort === null || !Number.isInteger(body.sort) || body.sort < 0) {
                return res.status(400).json({ error: 'Invalid sort' });
            }
            patch.sort = body.sort;
        }
        if (body.netPrice !== undefined) {
            if (body.netPrice !== null && !Number.isFinite(body.netPrice)) {
                return res.status(400).json({ error: 'Invalid price' });
            }
            patch.netPrice = body.netPrice;
        }
        if (body.taxId !== undefined) {
            if (body.taxId !== null && (typeof body.taxId !== 'number' || !Number.isInteger(body.taxId) || body.taxId <= 0)) {
                return res.status(400).json({ error: 'Invalid taxId' });
            }
            patch.taxId = body.taxId;
        }
        if (body.taxRate !== undefined) {
            if (body.taxRate !== null && (typeof body.taxRate !== 'number' || !Number.isFinite(body.taxRate) || body.taxRate < 0)) {
                return res.status(400).json({ error: 'Invalid taxRate' });
            }
            patch.taxRate = body.taxRate;
        }

        try {
            const supplier = await db.update(req.user.id, skuParsed.sku, idParsed.id, patch);
            emitArticleSignal(req, skuParsed.sku);
            res.status(200).json({ supplier });
        } catch (error) {
            const status = articleSupplierErrorStatus(error);
            if (status === 500) console.error('Update article supplier failed:', error);
            res.status(status).json({ error: error.message });
        }
    });

    app.delete(`${basePath}/article/:sku/supplier/:id`, async (req, res) => {
        const selected = requireSelectedCompany(req);
        if (selected.error) {
            return res.status(400).json({ error: selected.error });
        }

        const skuParsed = parseSku(req.params.sku);
        if (skuParsed.error) {
            return res.status(400).json({ error: skuParsed.error });
        }

        const idParsed = parsePositiveInt(req.params.id, 'id');
        if (idParsed.error) {
            return res.status(400).json({ error: idParsed.error });
        }

        try {
            await db.remove(req.user.id, skuParsed.sku, idParsed.id);
            emitArticleSignal(req, skuParsed.sku);
            res.sendStatus(204);
        } catch (error) {
            const status = articleSupplierErrorStatus(error);
            if (status === 500) console.error('Delete article supplier failed:', error);
            res.status(status).json({ error: error.message });
        }
    });

    /**
     * @openapi
     * /article/{sku}/supplier/order:
     *   put:
     *     tags: [Article]
     *     summary: Reorder article suppliers
     *     description: |
     *       Sets the display sort order of supplier assignments for an article.
     *       Expects an array of all assigned `articlesupplier` IDs in the desired order.
     *     security:
     *       - cookieAuth: []
     *     x-signals: [article-<sku>]
     *     x-markdown: article/supplier/order.md
     *     parameters:
     *       - in: path
     *         name: sku
     *         required: true
     *         schema:
     *           type: string
     *         description: Article SKU
     *     requestBody:
     *       required: true
     *       content:
     *         application/json:
     *           schema:
     *             type: object
     *             required: [ids]
     *             properties:
     *               ids:
     *                 type: array
     *                 items:
     *                   type: integer
     *                 description: Full list of articlesupplier ids in their new order
     *             example:
     *               ids: [12, 10, 15]
     *     responses:
     *       200:
     *         description: New order applied
     *         content:
     *           application/json:
     *             schema:
     *               type: object
     *               properties:
     *                 ids:
     *                   type: array
     *                   items:
     *                     type: integer
     *       400:
     *         description: Invalid supplier order, ids is required, or no company selected
     *         content:
     *           application/json:
     *             schema:
     *               $ref: '#/components/schemas/Error'
     *       401:
     *         description: Unauthorized
     *         content:
     *           application/json:
     *             schema:
     *               $ref: '#/components/schemas/Error'
     *       403:
     *         description: Not authorized
     *         content:
     *           application/json:
     *             schema:
     *               $ref: '#/components/schemas/Error'
     *       404:
     *         description: Article or company not found
     *         content:
     *           application/json:
     *             schema:
     *               $ref: '#/components/schemas/Error'
     */
    app.put(`${basePath}/article/:sku/supplier/order`, async (req, res) => {
        const selected = requireSelectedCompany(req);
        if (selected.error) {
            return res.status(400).json({ error: selected.error });
        }

        const skuParsed = parseSku(req.params.sku);
        if (skuParsed.error) {
            return res.status(400).json({ error: skuParsed.error });
        }

        const rawIds = req.body?.ids;
        if (!Array.isArray(rawIds)) {
            return res.status(400).json({ error: 'ids is required' });
        }

        const ids = [];
        for (const value of rawIds) {
            const id = Number(value);
            if (!Number.isInteger(id) || id <= 0) {
                return res.status(400).json({ error: 'Invalid supplier order' });
            }
            ids.push(id);
        }

        try {
            const result = await db.order(req.user.id, skuParsed.sku, { ids });
            emitArticleSignal(req, skuParsed.sku);
            res.status(200).json(result);
        } catch (error) {
            const status = articleSupplierErrorStatus(error);
            if (status === 500) console.error('Order article suppliers failed:', error);
            res.status(status).json({ error: error.message });
        }
    });
}