import * as db from '../../db/supplier.js';

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

function supplierErrorStatus(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 === 'Supplier not found') return 404;
    if (error.message === 'Supplier required') return 400;
    if (error.message === 'Name required') return 400;
    return 500;
}

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

function parseSkus(source) {
    if (source == null) return undefined;
    if (Array.isArray(source)) return source;
    if (typeof source === 'string') {
        const trimmed = source.trim();
        if (!trimmed) return [];
        if (trimmed.startsWith('[') && trimmed.endsWith(']')) {
            try {
                const parsed = JSON.parse(trimmed);
                if (Array.isArray(parsed)) return parsed;
            } catch {
                // fall through
            }
        }
        if (trimmed.includes(',')) {
            return trimmed.split(',').map((s) => s.trim()).filter(Boolean);
        }
        return [trimmed];
    }
    return undefined;
}

/**
 * Registers supplier routes for the authenticated user's selected company.
 * @param {import('express').Application} app
 * @param {string} [basePath='']
 */
export function register(app, basePath = '') {
    /**
     * @openapi
     * /supplier:
     *   get:
     *     tags: [Supplier]
     *     summary: List suppliers
     *     description: |
     *       Lists suppliers (`entity` rows in the company `Lieferanten` customergroup)
     *       for the authenticated user's selected company.
     *     security:
     *       - cookieAuth: []
     *     x-markdown: supplier/list.md
     *     responses:
     *       200:
     *         description: Supplier list
     *         content:
     *           application/json:
     *             schema:
     *               type: object
     *               properties:
     *                 suppliers:
     *                   type: array
     *                   items:
     *                     $ref: '#/components/schemas/Supplier'
     *       400:
     *         description: 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: Company not found
     *         content:
     *           application/json:
     *             schema:
     *               $ref: '#/components/schemas/Error'
     *   post:
     *     tags: [Supplier]
     *     summary: Create supplier
     *     description: |
     *       Creates a supplier in the company `Lieferanten` group (created on first use).
     *     security:
     *       - cookieAuth: []
     *     x-markdown: supplier/create.md
     *     requestBody:
     *       required: true
     *       content:
     *         application/json:
     *           schema:
     *             type: object
     *             required: [name]
     *             properties:
     *               name:
     *                 type: string
     *             example:
     *               name: Großhandel Müller
     *     responses:
     *       201:
     *         description: Created supplier
     *         content:
     *           application/json:
     *             schema:
     *               type: object
     *               properties:
     *                 supplier:
     *                   $ref: '#/components/schemas/Supplier'
     *       400:
     *         description: Name 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: Company not found
     *         content:
     *           application/json:
     *             schema:
     *               $ref: '#/components/schemas/Error'
     */
    app.get(`${basePath}/supplier`, async (req, res) => {
        const selected = requireSelectedCompany(req);
        if (selected.error) {
            return res.status(400).json({ error: selected.error });
        }

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

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

        const { name } = req.body ?? {};

        try {
            const supplier = await db.create(req.user.id, { name });
            res.status(201).json({ supplier });
        } catch (error) {
            const status = supplierErrorStatus(error);
            if (status === 500) console.error('Create supplier failed:', error);
            res.status(status).json({ error: error.message });
        }
    });

    /**
     * @openapi
     * /supplier/{id}:
     *   patch:
     *     tags: [Supplier]
     *     summary: Update supplier
     *     description: Renames a supplier for the selected company.
     *     security:
     *       - cookieAuth: []
     *     x-markdown: supplier/update.md
     *     parameters:
     *       - in: path
     *         name: id
     *         required: true
     *         schema:
     *           type: integer
     *     requestBody:
     *       required: true
     *       content:
     *         application/json:
     *           schema:
     *             type: object
     *             required: [name]
     *             properties:
     *               name:
     *                 type: string
     *             example:
     *               name: Großhandel Müller GmbH
     *     responses:
     *       200:
     *         description: Updated supplier
     *         content:
     *           application/json:
     *             schema:
     *               type: object
     *               properties:
     *                 supplier:
     *                   $ref: '#/components/schemas/Supplier'
     *       400:
     *         description: Name required, 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 or company not found
     *         content:
     *           application/json:
     *             schema:
     *               $ref: '#/components/schemas/Error'
     *   delete:
     *     tags: [Supplier]
     *     summary: Delete supplier
     *     description: |
     *       Deletes the supplier entity for the selected company.
     *       Related `entityhistory` cascades; `manifest.entity_id` is set null.
     *     security:
     *       - cookieAuth: []
     *     x-markdown: supplier/delete.md
     *     parameters:
     *       - in: path
     *         name: id
     *         required: true
     *         schema:
     *           type: integer
     *     responses:
     *       204:
     *         description: Deleted
     *       400:
     *         description: No company selected or invalid id
     *         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 not found
     *         content:
     *           application/json:
     *             schema:
     *               $ref: '#/components/schemas/Error'
     */
    app.patch(`${basePath}/supplier/:id`, async (req, res) => {
        const selected = requireSelectedCompany(req);
        if (selected.error) {
            return res.status(400).json({ error: selected.error });
        }

        const id = Number(req.params.id);
        if (!Number.isInteger(id) || id <= 0) {
            return res.status(400).json({ error: 'id is required' });
        }

        const { name } = req.body ?? {};

        try {
            const supplier = await db.update(req.user.id, id, { name });
            res.status(200).json({ supplier });
        } catch (error) {
            const status = supplierErrorStatus(error);
            if (status === 500) console.error('Update supplier failed:', error);
            res.status(status).json({ error: error.message });
        }
    });

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

        const id = Number(req.params.id);
        if (!Number.isInteger(id) || id <= 0) {
            return res.status(400).json({ error: 'id is required' });
        }

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

    /**
     * @openapi
     * /supplier/{id}/articles:
     *   get:
     *     tags: [Supplier]
     *     summary: List supplier articles by SKUs
     *     description: |
     *       Lists article-supplier assignments for the specified supplier (entity ID),
     *       optionally filtered by a list of SKUs (matching either article SKU or supplier SKU).
     *       Includes linked article details (name, slug, photos/articlepic, eans/articleean).
     *     security:
     *       - cookieAuth: []
     *     x-markdown: supplier/articles.get.md
     *     parameters:
     *       - in: path
     *         name: id
     *         required: true
     *         schema:
     *           type: integer
     *         description: Supplier entity ID
     *       - in: query
     *         name: skus
     *         required: false
     *         schema:
     *           oneOf:
     *             - type: array
     *               items:
     *                 type: string
     *             - type: string
     *         description: Optional SKU or comma-separated SKUs to filter by
     *     responses:
     *       200:
     *         description: List of supplier articles
     *         content:
     *           application/json:
     *             schema:
     *               type: object
     *               properties:
     *                 articles:
     *                   type: array
     *                   items:
     *                     $ref: '#/components/schemas/SupplierArticle'
     *       400:
     *         description: No company selected or invalid id
     *         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 or company not found
     *         content:
     *           application/json:
     *             schema:
     *               $ref: '#/components/schemas/Error'
     *   post:
     *     tags: [Supplier]
     *     summary: Query supplier articles by SKUs (bulk)
     *     description: |
     *       Queries article-supplier assignments for the specified supplier (entity ID) with a
     *       JSON list of SKUs in the request body, avoiding URL length limits for large SKU lists.
     *       Includes linked article details (name, slug, photos/articlepic, eans/articleean).
     *     security:
     *       - cookieAuth: []
     *     x-markdown: supplier/articles.post.md
     *     parameters:
     *       - in: path
     *         name: id
     *         required: true
     *         schema:
     *           type: integer
     *         description: Supplier entity ID
     *     requestBody:
     *       required: false
     *       content:
     *         application/json:
     *           schema:
     *             type: object
     *             properties:
     *               skus:
     *                 type: array
     *                 items:
     *                   type: string
     *                 description: List of SKUs to filter by (empty array returns empty list)
     *             example:
     *               skus: ['SKU-1', 'SKU-2']
     *     responses:
     *       200:
     *         description: List of supplier articles
     *         content:
     *           application/json:
     *             schema:
     *               type: object
     *               properties:
     *                 articles:
     *                   type: array
     *                   items:
     *                     $ref: '#/components/schemas/SupplierArticle'
     *       400:
     *         description: No company selected or invalid id
     *         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 or company not found
     *         content:
     *           application/json:
     *             schema:
     *               $ref: '#/components/schemas/Error'
     */
    async function handleGetSupplierArticles(req, res) {
        const selected = requireSelectedCompany(req);
        if (selected.error) {
            return res.status(400).json({ error: selected.error });
        }

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

        const skus = parseSkus(req.query.skus ?? req.query.sku);

        try {
            const articles = await db.listArticlesBySkus(req.user.id, idParsed.id, skus);
            res.status(200).json({ articles });
        } catch (error) {
            const status = supplierErrorStatus(error);
            if (status === 500) console.error('List supplier articles failed:', error);
            res.status(status).json({ error: error.message });
        }
    }

    async function handlePostSupplierArticles(req, res) {
        const selected = requireSelectedCompany(req);
        if (selected.error) {
            return res.status(400).json({ error: selected.error });
        }

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

        const skus = parseSkus(req.body?.skus ?? req.body?.sku);

        try {
            const articles = await db.listArticlesBySkus(req.user.id, idParsed.id, skus);
            res.status(200).json({ articles });
        } catch (error) {
            const status = supplierErrorStatus(error);
            if (status === 500) console.error('Query supplier articles failed:', error);
            res.status(status).json({ error: error.message });
        }
    }

    app.get(`${basePath}/supplier/:id/articles`, handleGetSupplierArticles);
    app.get(`${basePath}/supplier/:id/article`, handleGetSupplierArticles);
    app.post(`${basePath}/supplier/:id/articles`, handlePostSupplierArticles);
    app.post(`${basePath}/supplier/:id/article`, handlePostSupplierArticles);
}