import * as db from '../../db/shipping.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 shippingErrorStatus(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?.includes('not a shipment')
    ) {
        return 400;
    }
    if (
        error.message?.includes('cannot be deleted') ||
        error.message?.includes('cannot be undone') ||
        error.message?.includes('already shipped')
    ) {
        return 409;
    }
    return 500;
}

function emitShippingEvents(companyId) {
    emit('stock', { companyId });
    emit('ledger', { companyId });
    emit('articles', { companyId });
    emit('order', { companyId });
}

// #endregion

/**
 * Registers shipping routes (shippings belong to an order / manifest).
 * @param {import('express').Application} app
 * @param {string} [basePath='']
 */
export function register(app, basePath = '') {
    /**
     * @openapi
     * /order/{id}/shipping:
     *   get:
     *     tags: [Shipping]
     *     summary: List shippings of an order
     *     description: Lists shippings of the order (manifest) for the selected company.
     *     security:
     *       - cookieAuth: []
     *     parameters:
     *       - in: path
     *         name: id
     *         required: true
     *         schema:
     *           type: integer
     *         description: Order ID
     *     responses:
     *       200:
     *         description: List of shippings
     *         content:
     *           application/json:
     *             schema:
     *               type: object
     *               properties:
     *                 shippings:
     *                   type: array
     *                   items:
     *                     $ref: '#/components/schemas/Shipping'
     *       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/shipping

    app.get(`${basePath}/order/:id/shipping`, 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 shippings = await db.listByManifestId(req.user.id, parsedId.id);
            res.status(200).json({ shippings });
        } catch (error) {
            const status = shippingErrorStatus(error);
            if (status === 500) console.error('List shippings failed:', error);
            res.status(status).json({ error: error.message });
        }
    });

    // #endregion

    /**
     * @openapi
     * /order/{id}/shipping:
     *   post:
     *     tags: [Shipping]
     *     summary: Create shipping for an order
     *     description: |
     *       Creates a shipping for the order. The shipping number is allocated from the
     *       `shipping` number sequence (prefix and counter from the numbers API).
     *       If `state` is `shipped`, stock is adjusted via the ledger and article history is written.
     *     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: [carrierId, type, state]
     *             properties:
     *               carrierId:
     *                 type: integer
     *                 description: Carrier ID
     *               type:
     *                 type: string
     *               state:
     *                 type: string
     *               trackingCode:
     *                 type: string
     *                 description: Carrier parcel tracking code
     *               warehouseId:
     *                 type: integer
     *                 description: Optional warehouse ID for stock deduction when state is shipped
     *     responses:
     *       201:
     *         description: Created shipping
     *         content:
     *           application/json:
     *             schema:
     *               type: object
     *               properties:
     *                 shipping:
     *                   $ref: '#/components/schemas/Shipping'
     *       400:
     *         description: Validation error 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: Order or warehouse not found
     *         content:
     *           application/json:
     *             schema:
     *               $ref: '#/components/schemas/Error'
     *       409:
     *         description: Order already shipped
     *         content:
     *           application/json:
     *             schema:
     *               $ref: '#/components/schemas/Error'
     */
    // #region POST /order/:id/shipping

    app.post(`${basePath}/order/:id/shipping`, 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 shipping = await db.create(req.user.id, {
                ...(req.body ?? {}),
                manifestId: parsedId.id,
            });
            if (String(shipping.state || '').trim().toLowerCase() === 'shipped') {
                emitShippingEvents(selected.companyId);
            }
            res.status(201).json({ shipping });
        } catch (error) {
            const status = shippingErrorStatus(error);
            if (status === 500) console.error('Create shipping failed:', error);
            res.status(status).json({ error: error.message });
        }
    });

    // #endregion

    /**
     * @openapi
     * /shipment/{id}/shipping:
     *   get:
     *     tags: [Shipping]
     *     summary: List packages of a shipment
     *     description: Lists all packages (shippings) belonging to the specified shipment manifest.
     *     security:
     *       - cookieAuth: []
     *     parameters:
     *       - in: path
     *         name: id
     *         required: true
     *         schema:
     *           type: integer
     *         description: Shipment ID
     *     responses:
     *       200:
     *         description: List of packages
     *         content:
     *           application/json:
     *             schema:
     *               type: object
     *               properties:
     *                 shippings:
     *                   type: array
     *                   items:
     *                     $ref: '#/components/schemas/Shipping'
     *       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/shipping

    app.get(`${basePath}/shipment/:id/shipping`, 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 shippings = await db.listByManifestId(req.user.id, parsedId.id);
            res.status(200).json({ shippings });
        } catch (error) {
            const status = shippingErrorStatus(error);
            if (status === 500) console.error('List shipment packages failed:', error);
            res.status(status).json({ error: error.message });
        }
    });

    // #endregion

    /**
     * @openapi
     * /shipment/{id}/shipping:
     *   post:
     *     tags: [Shipping]
     *     summary: Create package for a shipment
     *     description: |
     *       Creates a physical package (shipping) for the shipment manifest.
     *       Accepts carrier and parcel tracking code. If state is `shipped`,
     *       deducts stock for the shipment's lines via ledger movements.
     *     security:
     *       - cookieAuth: []
     *     parameters:
     *       - in: path
     *         name: id
     *         required: true
     *         schema:
     *           type: integer
     *         description: Shipment ID
     *     requestBody:
     *       required: true
     *       content:
     *         application/json:
     *           schema:
     *             type: object
     *             required: [carrierId, type, state]
     *             properties:
     *               carrierId:
     *                 type: integer
     *                 description: Carrier ID
     *               type:
     *                 type: string
     *               state:
     *                 type: string
     *               trackingCode:
     *                 type: string
     *                 description: Carrier parcel tracking code
     *               warehouseId:
     *                 type: integer
     *                 description: Optional warehouse ID for stock deduction when state is shipped
     *     responses:
     *       201:
     *         description: Created package
     *         content:
     *           application/json:
     *             schema:
     *               type: object
     *               properties:
     *                 shipping:
     *                   $ref: '#/components/schemas/Shipping'
     *       400:
     *         description: Validation error, manifest is not a shipment, 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 or warehouse not found
     *         content:
     *           application/json:
     *             schema:
     *               $ref: '#/components/schemas/Error'
     */
    // #region POST /shipment/:id/shipping

    app.post(`${basePath}/shipment/:id/shipping`, 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 shipping = await db.create(req.user.id, {
                ...(req.body ?? {}),
                manifestId: parsedId.id,
            });
            if (String(shipping.state || '').trim().toLowerCase() === 'shipped') {
                emitShippingEvents(selected.companyId);
            }
            res.status(201).json({ shipping });
        } catch (error) {
            const status = shippingErrorStatus(error);
            if (status === 500) console.error('Create shipment package failed:', error);
            res.status(status).json({ error: error.message });
        }
    });

    // #endregion

    /**
     * @openapi
     * /shipping/{id}:
     *   patch:
     *     tags: [Shipping]
     *     summary: Update shipping
     *     description: |
     *       Updates a shipping record. If transitioned to `shipped`, stock is adjusted
     *       via ledger and article history is written. Once shipped, it cannot be undone.
     *     security:
     *       - cookieAuth: []
     *     parameters:
     *       - in: path
     *         name: id
     *         required: true
     *         schema:
     *           type: integer
     *         description: Shipping ID
     *     requestBody:
     *       required: true
     *       content:
     *         application/json:
     *           schema:
     *             type: object
     *             properties:
     *               type:
     *                 type: string
     *               state:
     *                 type: string
     *               trackingCode:
     *                 type: string
     *                 description: Carrier parcel tracking code
     *               carrierId:
     *                 type: integer
     *                 description: Carrier ID
     *               warehouseId:
     *                 type: integer
     *                 description: Warehouse ID for stock deduction when transitioning to shipped
     *     responses:
     *       200:
     *         description: Updated shipping
     *         content:
     *           application/json:
     *             schema:
     *               type: object
     *               properties:
     *                 shipping:
     *                   $ref: '#/components/schemas/Shipping'
     *       400:
     *         description: Validation error 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: Shipping or warehouse not found
     *         content:
     *           application/json:
     *             schema:
     *               $ref: '#/components/schemas/Error'
     *       409:
     *         description: Shipped shipping cannot be undone, or order already shipped
     *         content:
     *           application/json:
     *             schema:
     *               $ref: '#/components/schemas/Error'
     */
    // #region PATCH /shipping/:id

    app.patch(`${basePath}/shipping/: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 shipping = await db.update(req.user.id, parsedId.id, req.body ?? {});
            if (String(shipping.state || '').trim().toLowerCase() === 'shipped') {
                emitShippingEvents(selected.companyId);
            }
            res.status(200).json({ shipping });
        } catch (error) {
            const status = shippingErrorStatus(error);
            if (status === 500) console.error('Update shipping failed:', error);
            res.status(status).json({ error: error.message });
        }
    });

    // #endregion

    /**
     * @openapi
     * /shipping/{id}:
     *   delete:
     *     tags: [Shipping]
     *     summary: Delete shipping
     *     description: |
     *       Deletes a shipping of the selected company. Its packages are removed as well.
     *       Shipped shippings cannot be deleted because stock movements have been ledgered.
     *     security:
     *       - cookieAuth: []
     *     parameters:
     *       - in: path
     *         name: id
     *         required: true
     *         schema:
     *           type: integer
     *         description: Shipping ID
     *     responses:
     *       204:
     *         description: Shipping 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'
     *       403:
     *         description: Not authorized
     *         content:
     *           application/json:
     *             schema:
     *               $ref: '#/components/schemas/Error'
     *       404:
     *         description: Shipping not found
     *         content:
     *           application/json:
     *             schema:
     *               $ref: '#/components/schemas/Error'
     *       409:
     *         description: Shipped shipping cannot be deleted
     *         content:
     *           application/json:
     *             schema:
     *               $ref: '#/components/schemas/Error'
     */
    // #region DELETE /shipping/:id

    app.delete(`${basePath}/shipping/: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);
            res.status(204).end();
        } catch (error) {
            const status = shippingErrorStatus(error);
            if (status === 500) console.error('Delete shipping failed:', error);
            res.status(status).json({ error: error.message });
        }
    });

    // #endregion
}