import * as db from '../../db/shipment.js';
import { createAndAttachManifestPdf } from '../../services/manifestPdf.js';
import { emit } from '../sse.js';

// #region Helpers

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

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

function shipmentErrorStatus(error) {
    if (error.message === 'No company selected') return 400;
    if (error.message === 'Not authorized') return 403;
    if (error.message?.endsWith(' not found')) return 404;
    if (
        error.message?.endsWith(' required') ||
        error.message?.startsWith('Article (') ||
        error.message?.includes('Invalid lines')
    ) {
        return 400;
    }
    if (
        error.message?.startsWith('Shipment amount exceeds') ||
        error.message?.includes('cannot be deleted') ||
        error.message?.includes('cannot be undone') ||
        error.message?.includes('already shipped')
    ) {
        return 409;
    }
    return 500;
}

function emitShipmentEvents(companyId) {
    emit('order', { companyId });
    emit('shipment', { companyId });
}

// #endregion

/**
 * Registers shipment routes (shipments belong to an order).
 * @param {import('express').Application} app
 * @param {string} [basePath='']
 */
export function register(app, basePath = '') {
    /**
     * @openapi
     * /order/{id}/shipment:
     *   get:
     *     tags: [Shipment]
     *     summary: List shipments of an order
     *     description: Lists all shipment manifests belonging to the specified order.
     *     security:
     *       - cookieAuth: []
     *     parameters:
     *       - in: path
     *         name: id
     *         required: true
     *         schema:
     *           type: integer
     *         description: Order ID
     *     responses:
     *       200:
     *         description: List of shipments
     *         content:
     *           application/json:
     *             schema:
     *               type: object
     *               properties:
     *                 shipments:
     *                   type: array
     *                   items:
     *                     $ref: '#/components/schemas/Shipment'
     *       400:
     *         description: 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'
     *       404:
     *         description: Order not found
     *         content:
     *           application/json:
     *             schema:
     *               $ref: '#/components/schemas/Error'
     */
    // #region GET /order/:id/shipment

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

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

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

    // #endregion

    /**
     * @openapi
     * /order/{id}/shipment:
     *   post:
     *     tags: [Shipment]
     *     summary: Create shipment for an order
     *     description: |
     *       Creates a new partial or full shipment manifest for the order.
     *       Validates that article positions belong to the order and cumulative shipped quantities
     *       do not exceed ordered quantities.
     *     security:
     *       - cookieAuth: []
     *     parameters:
     *       - in: path
     *         name: id
     *         required: true
     *         schema:
     *           type: integer
     *         description: Order ID
     *     requestBody:
     *       required: true
     *       content:
     *         application/json:
     *           schema:
     *             type: object
     *             required: [lines]
     *             properties:
     *               date:
     *                 type: string
     *                 format: date
     *               externalNumber:
     *                 type: string
     *               lines:
     *                 type: array
     *                 items:
     *                   type: object
     *                   required: [sku, amount]
     *                   properties:
     *                     sku:
     *                       type: string
     *                     amount:
     *                       type: number
     *                     name:
     *                       type: string
     *                     pu:
     *                       type: number
     *                     net:
     *                       type: number
     *                     rebate:
     *                       type: number
     *                     taxrate:
     *                       type: number
     *                     comment:
     *                       type: string
     *     responses:
     *       201:
     *         description: Created shipment
     *         content:
     *           application/json:
     *             schema:
     *               type: object
     *               properties:
     *                 shipment:
     *                   $ref: '#/components/schemas/Shipment'
     *       400:
     *         description: Validation error or article not in order
     *         content:
     *           application/json:
     *             schema:
     *               $ref: '#/components/schemas/Error'
     *       401:
     *         description: Unauthorized
     *         content:
     *           application/json:
     *             schema:
     *               $ref: '#/components/schemas/Error'
     *       404:
     *         description: Order not found
     *         content:
     *           application/json:
     *             schema:
     *               $ref: '#/components/schemas/Error'
     *       409:
     *         description: Cumulative shipment amount exceeds ordered amount
     *         content:
     *           application/json:
     *             schema:
     *               $ref: '#/components/schemas/Error'
     */
    // #region POST /order/:id/shipment

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

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

        try {
            const shipment = await db.create(req.user.id, {
                ...(req.body ?? {}),
                orderId: parsedId.id,
            });
            emitShipmentEvents(selected.companyId);
            res.status(201).json({ shipment });
        } catch (error) {
            const status = shipmentErrorStatus(error);
            if (status === 500) console.error('Create shipment failed:', error);
            res.status(status).json({ error: error.message });
        }
    });

    // #endregion

    /**
     * @openapi
     * /shipment/{id}:
     *   get:
     *     tags: [Shipment]
     *     summary: Get shipment by ID
     *     description: Retrieves shipment header, article positions, and attached packages.
     *     security:
     *       - cookieAuth: []
     *     parameters:
     *       - in: path
     *         name: id
     *         required: true
     *         schema:
     *           type: integer
     *         description: Shipment ID
     *     responses:
     *       200:
     *         description: Shipment details
     *         content:
     *           application/json:
     *             schema:
     *               type: object
     *               properties:
     *                 shipment:
     *                   $ref: '#/components/schemas/Shipment'
     *       400:
     *         description: 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'
     *       404:
     *         description: Shipment not found
     *         content:
     *           application/json:
     *             schema:
     *               $ref: '#/components/schemas/Error'
     */
    // #region GET /shipment/:id

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

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

        try {
            const shipment = await db.getById(req.user.id, parsedId.id);
            res.status(200).json({ shipment });
        } catch (error) {
            const status = shipmentErrorStatus(error);
            if (status === 500) console.error('Get shipment failed:', error);
            res.status(status).json({ error: error.message });
        }
    });

    // #endregion

    /**
     * @openapi
     * /shipment/{id}:
     *   delete:
     *     tags: [Shipment]
     *     summary: Delete shipment
     *     description: Deletes an unshipped shipment manifest. Shipped shipments cannot be deleted.
     *     security:
     *       - cookieAuth: []
     *     parameters:
     *       - in: path
     *         name: id
     *         required: true
     *         schema:
     *           type: integer
     *         description: Shipment ID
     *     responses:
     *       204:
     *         description: Shipment deleted
     *       400:
     *         description: 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'
     *       404:
     *         description: Shipment not found
     *         content:
     *           application/json:
     *             schema:
     *               $ref: '#/components/schemas/Error'
     *       409:
     *         description: Shipped shipment cannot be deleted
     *         content:
     *           application/json:
     *             schema:
     *               $ref: '#/components/schemas/Error'
     */
    // #region DELETE /shipment/:id

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

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

        try {
            await db.remove(req.user.id, parsedId.id);
            emitShipmentEvents(selected.companyId);
            res.status(204).end();
        } catch (error) {
            const status = shipmentErrorStatus(error);
            if (status === 500) console.error('Delete shipment failed:', error);
            res.status(status).json({ error: error.message });
        }
    });

    // #endregion

    /**
     * @openapi
     * /shipment/{id}/pdf:
     *   post:
     *     tags: [Shipment]
     *     summary: Generate and attach shipment PDF (delivery note)
     *     description: |
     *       Generates an A4 delivery note PDF document for the shipment with line items and package tracking.
     *       Shipping slips contain no price information.
     *       Attaches the PDF as a `manifestattachment` to the shipment so it can be printed or attached to packages.
     *     security:
     *       - cookieAuth: []
     *     x-signals: [shipment]
     *     parameters:
     *       - in: path
     *         name: id
     *         required: true
     *         schema:
     *           type: integer
     *         description: Shipment ID
     *     responses:
     *       201:
     *         description: PDF generated and attached to shipment
     *         content:
     *           application/json:
     *             schema:
     *               type: object
     *               required: [attachment, fileUrl]
     *               properties:
     *                 attachment:
     *                   $ref: '#/components/schemas/DeliveryFile'
     *                 fileUrl:
     *                   type: string
     *                   example: /shipment/1/file/5
     *       400:
     *         description: 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: Shipment not found
     *         content:
     *           application/json:
     *             schema:
     *               $ref: '#/components/schemas/Error'
     */
    // #region POST /shipment/:id/pdf

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

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

        try {
            const { attachment } = await createAndAttachManifestPdf(
                req.user.id,
                selected.companyId,
                parsedId.id,
                'shipment'
            );

            res.status(201).json({
                attachment,
                fileUrl: `/shipment/${parsedId.id}/file/${attachment.fileId}`,
            });
        } catch (error) {
            const status = shipmentErrorStatus(error);
            if (status === 500) console.error('Create shipment PDF failed:', error);
            res.status(status).json({ error: error.message });
        }
    });

    // #endregion

    /**
     * @openapi
     * /shipment/{id}/file/{fileId}:
     *   get:
     *     tags: [Shipment]
     *     summary: Get shipment attachment file content
     *     description: |
     *       Returns the full binary content of an attached file (e.g. shipment delivery note PDF)
     *       for the specified shipment. Supports HTTP caching via ETag (SHA-256 hash) and 304 Not Modified.
     *     security:
     *       - cookieAuth: []
     *     parameters:
     *       - in: path
     *         name: id
     *         required: true
     *         schema:
     *           type: integer
     *         description: Shipment ID
     *       - in: path
     *         name: fileId
     *         required: true
     *         schema:
     *           type: integer
     *         description: File ID or attachment ID
     *       - in: query
     *         name: download
     *         required: false
     *         schema:
     *           type: boolean
     *         description: When true, sets Content-Disposition to attachment instead of inline
     *     responses:
     *       200:
     *         description: Binary file content
     *         content:
     *           application/pdf:
     *             schema:
     *               type: string
     *               format: binary
     *           application/octet-stream:
     *             schema:
     *               type: string
     *               format: binary
     *       304:
     *         description: Not modified
     *       400:
     *         description: Invalid ID or no company selected
     *         content:
     *           application/json:
     *             schema:
     *               $ref: '#/components/schemas/Error'
     *       404:
     *         description: Shipment or file not found
     *         content:
     *           application/json:
     *             schema:
     *               $ref: '#/components/schemas/Error'
     */
    // #region GET /shipment/:id/file/:fileId

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

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

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

        try {
            const attachment = await db.getFile(req.user.id, parsedId.id, parsedFileId.id);

            if (attachment.hash) {
                const etag = `"${attachment.hash}"`;
                res.setHeader('ETag', etag);
                const ifNoneMatch = req.headers['if-none-match'];
                if (ifNoneMatch === etag || ifNoneMatch === attachment.hash) {
                    return res.status(304).end();
                }
            }

            const isDownload = req.query.download === '1' || req.query.download === 'true';
            const dispositionType = isDownload ? 'attachment' : 'inline';
            const filename = attachment.name || `file-${attachment.fileId}`;
            const asciiName = filename.replace(/["\r\n\\]/g, '_');
            const encodedName = encodeURIComponent(filename).replace(/['()]/g, escape);

            res.setHeader('Content-Type', attachment.mimetype || 'application/octet-stream');
            res.setHeader('Content-Disposition', `${dispositionType}; filename="${asciiName}"; filename*=UTF-8''${encodedName}`);
            res.setHeader('Cache-Control', 'private, max-age=86400');

            if (attachment.content && Buffer.isBuffer(attachment.content)) {
                res.setHeader('Content-Length', String(attachment.content.length));
                return res.status(200).send(attachment.content);
            } else {
                const buffer = Buffer.from(attachment.content || '');
                res.setHeader('Content-Length', String(buffer.length));
                return res.status(200).send(buffer);
            }
        } catch (error) {
            const status = shipmentErrorStatus(error);
            if (status === 500) console.error('Get shipment file failed:', error);
            res.status(status).json({ error: error.message });
        }
    });

    // #endregion

    /**
     * @openapi
     * /shipment/{id}/file/{fileId}:
     *   delete:
     *     tags: [Shipment]
     *     summary: Delete shipment file attachment
     *     description: |
     *       Removes a file attachment from the shipment and deletes the underlying file.
     *     security:
     *       - cookieAuth: []
     *     x-signals: [shipment, order]
     *     parameters:
     *       - in: path
     *         name: id
     *         required: true
     *         schema:
     *           type: integer
     *         description: Shipment ID
     *       - in: path
     *         name: fileId
     *         required: true
     *         schema:
     *           type: integer
     *         description: File ID or attachment ID
     *     responses:
     *       204:
     *         description: Attachment deleted
     *       400:
     *         description: Invalid parameters 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: Shipment or attachment not found
     *         content:
     *           application/json:
     *             schema:
     *               $ref: '#/components/schemas/Error'
     */
    // #region DELETE /shipment/:id/file/:fileId

    app.delete(`${basePath}/shipment/:id/file/:fileId`, 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 fileId = Number(req.params.fileId);
        if (!Number.isInteger(fileId) || fileId <= 0) {
            return res.status(400).json({ error: 'fileId is required' });
        }

        try {
            await db.removeAttachment(req.user.id, id, fileId);
            emitShipmentEvents(selected.companyId);
            res.sendStatus(204);
        } catch (error) {
            const status = shipmentErrorStatus(error);
            if (status === 500) console.error('Delete shipment attachment failed:', error);
            res.status(status).json({ error: error.message });
        }
    });

    // #endregion
}