import * as db from '../../db/company.js';
import * as googleAuth from '../../db/googleAuth.js';
import { clearCachedUser } from '../middleware/auth.js';

function userPayload(authRow) {
    return {
        id: authRow.id,
        email: authRow.email,
        selectedCompanyId: authRow.selectedCompanyId,
    };
}

function parseCompanyBody(body) {
    const { iso639, name, taxrate, reducedtaxrate } = body ?? {};
    if (!iso639 || !name || taxrate == null || reducedtaxrate == null) {
        return { error: 'iso639, name, taxrate, and reducedtaxrate are required' };
    }
    if (typeof taxrate !== 'number' || !Number.isFinite(taxrate) || taxrate < 0) {
        return { error: 'taxrate must be a non-negative number' };
    }
    if (typeof reducedtaxrate !== 'number' || !Number.isFinite(reducedtaxrate) || reducedtaxrate < 0) {
        return { error: 'reducedtaxrate must be a non-negative number' };
    }
    return { iso639, name, taxrate, reducedtaxrate };
}

function parseCompanyId(id) {
    const companyId = Number(id);
    if (!Number.isInteger(companyId) || companyId <= 0) {
        return { error: 'Invalid company id' };
    }
    return { companyId };
}

function companyErrorStatus(error) {
    if (error.message === 'Company not found') return 404;
    if (error.message === 'Company name not available') return 409;
    if (error.message === 'Invalid tax rate') return 400;
    return 500;
}

/**
 * Registers company CRUD routes (requires auth middleware).
 * @param {import('express').Application} app - Express app
 * @param {string} [basePath=''] - Optional URL prefix for all routes in this module
 */
export function register(app, basePath = '') {
    /**
     * @openapi
     * /company:
     *   get:
     *     tags: [Company]
     *     summary: List companies
     *     description: Lists companies for the authenticated user.
     *     security:
     *       - cookieAuth: []
     *     x-markdown: company/list.md
     *     responses:
     *       200:
     *         description: Company list
     *         content:
     *           application/json:
     *             schema:
     *               type: object
     *               properties:
     *                 companies:
     *                   type: array
     *                   items:
     *                     $ref: '#/components/schemas/Company'
     *       401:
     *         description: Unauthorized
     *         content:
     *           application/json:
     *             schema:
     *               $ref: '#/components/schemas/Error'
     *       500:
     *         description: Server error
     *         content:
     *           application/json:
     *             schema:
     *               $ref: '#/components/schemas/Error'
     *   post:
     *     tags: [Company]
     *     summary: Create company
     *     description: Creates a company and selects it for the current user.
     *     security:
     *       - cookieAuth: []
     *     x-markdown: company/create.md
     *     requestBody:
     *       required: true
     *       content:
     *         application/json:
     *           schema:
     *             type: object
     *             required: [iso639, name, taxrate, reducedtaxrate]
     *             properties:
     *               iso639:
     *                 type: string
     *               name:
     *                 type: string
     *               taxrate:
     *                 type: number
     *               reducedtaxrate:
     *                 type: number
     *             example:
     *               iso639: de
     *               name: Acme GmbH
     *               taxrate: 19
     *               reducedtaxrate: 7
     *     responses:
     *       201:
     *         description: Created; selected company updated
     *         content:
     *           application/json:
     *             schema:
     *               type: object
     *               properties:
     *                 company:
     *                   $ref: '#/components/schemas/Company'
     *                 user:
     *                   $ref: '#/components/schemas/User'
     *       400:
     *         description: Validation error
     *         content:
     *           application/json:
     *             schema:
     *               $ref: '#/components/schemas/Error'
     *       401:
     *         description: Unauthorized
     *         content:
     *           application/json:
     *             schema:
     *               $ref: '#/components/schemas/Error'
     *       409:
     *         description: Company name not available
     *         content:
     *           application/json:
     *             schema:
     *               $ref: '#/components/schemas/Error'
     */
    app.get(`${basePath}/company`, async (req, res) => {
        try {
            const companies = await db.listCompanies(req.user.id);
            res.status(200).json({ companies });
        } catch (error) {
            console.error('List companies failed:', error);
            res.status(500).json({ error: 'Failed to list companies' });
        }
    });

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

        try {
            const company = await db.createCompany(req.user.id, body);
            await googleAuth.setSelectedCompany(req.user.id, company.id);
            clearCachedUser(req.user.id);
            const authRow = await googleAuth.getAllowedEmail(req.user.email);
            res.status(201).json({ company, user: userPayload(authRow) });
        } catch (error) {
            const status = companyErrorStatus(error);
            if (status === 500) console.error('Create company failed:', error);
            res.status(status).json({ error: error.message });
        }
    });

    /**
     * @openapi
     * /company/{id}:
     *   put:
     *     tags: [Company]
     *     summary: Update company
     *     description: Updates a company.
     *     security:
     *       - cookieAuth: []
     *     x-markdown: company/update.md
     *     parameters:
     *       - in: path
     *         name: id
     *         required: true
     *         schema:
     *           type: integer
     *     requestBody:
     *       required: true
     *       content:
     *         application/json:
     *           schema:
     *             type: object
     *             required: [iso639, name, taxrate, reducedtaxrate]
     *             properties:
     *               iso639:
     *                 type: string
     *               name:
     *                 type: string
     *               taxrate:
     *                 type: number
     *               reducedtaxrate:
     *                 type: number
     *     responses:
     *       200:
     *         description: Updated
     *         content:
     *           application/json:
     *             schema:
     *               type: object
     *               properties:
     *                 company:
     *                   $ref: '#/components/schemas/Company'
     *       400:
     *         description: Validation error
     *         content:
     *           application/json:
     *             schema:
     *               $ref: '#/components/schemas/Error'
     *       401:
     *         description: Unauthorized
     *         content:
     *           application/json:
     *             schema:
     *               $ref: '#/components/schemas/Error'
     *       404:
     *         description: Company not found
     *         content:
     *           application/json:
     *             schema:
     *               $ref: '#/components/schemas/Error'
     *       409:
     *         description: Company name not available
     *         content:
     *           application/json:
     *             schema:
     *               $ref: '#/components/schemas/Error'
     *   delete:
     *     tags: [Company]
     *     summary: Delete company
     *     description: Deletes a company.
     *     security:
     *       - cookieAuth: []
     *     x-markdown: company/delete.md
     *     parameters:
     *       - in: path
     *         name: id
     *         required: true
     *         schema:
     *           type: integer
     *     responses:
     *       204:
     *         description: Deleted
     *       400:
     *         description: Invalid id
     *         content:
     *           application/json:
     *             schema:
     *               $ref: '#/components/schemas/Error'
     *       401:
     *         description: Unauthorized
     *         content:
     *           application/json:
     *             schema:
     *               $ref: '#/components/schemas/Error'
     *       500:
     *         description: Server error
     *         content:
     *           application/json:
     *             schema:
     *               $ref: '#/components/schemas/Error'
     */
    app.put(`${basePath}/company/:id`, async (req, res) => {
        const parsedId = parseCompanyId(req.params.id);
        if (parsedId.error) {
            return res.status(400).json({ error: parsedId.error });
        }

        const body = parseCompanyBody(req.body);
        if (body.error) {
            return res.status(400).json({ error: body.error });
        }

        try {
            const company = await db.updateCompany(parsedId.companyId, body);
            res.status(200).json({ company });
        } catch (error) {
            const status = companyErrorStatus(error);
            if (status === 500) console.error('Update company failed:', error);
            res.status(status).json({ error: error.message });
        }
    });

    app.delete(`${basePath}/company/:id`, async (req, res) => {
        const parsedId = parseCompanyId(req.params.id);
        if (parsedId.error) {
            return res.status(400).json({ error: parsedId.error });
        }

        try {
            await db.deleteCompany(parsedId.companyId);
            res.sendStatus(204);
        } catch (error) {
            console.error('Delete company failed:', error);
            res.status(500).json({ error: 'Failed to delete company' });
        }
    });
}