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

// #region Helpers

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

function unitErrorStatus(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 === 'Unit not found') return 404;
    if (error.message === 'Invalid unit') return 400;
    if (error.message === 'Unit in use') return 409;
    return 500;
}

// #endregion

/**
 * Registers unit routes for the authenticated user's selected company.
 * @param {import('express').Application} app
 * @param {string} [basePath='']
 */
export function register(app, basePath = '') {
    /**
     * @openapi
     * /unit:
     *   get:
     *     tags: [Unit]
     *     summary: List units
     *     description: Lists units for the authenticated user's selected company (default-language symbol/name).
     *     security:
     *       - cookieAuth: []
     *     x-markdown: unit/list.md
     *     responses:
     *       200:
     *         description: Unit list
     *         content:
     *           application/json:
     *             schema:
     *               type: object
     *               properties:
     *                 units:
     *                   type: array
     *                   items:
     *                     $ref: '#/components/schemas/Unit'
     *       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'
     *   put:
     *     tags: [Unit]
     *     summary: Upsert unit
     *     description: |
     *       Insert or update unit by `si` for the selected company. Upserts `unittext` for the company language.
     *       `basesifactor` must be finite and `> 0`.
     *     security:
     *       - cookieAuth: []
     *     x-markdown: unit/upsert.md
     *     requestBody:
     *       required: true
     *       content:
     *         application/json:
     *           schema:
     *             type: object
     *             required: [si, basesi, basesifactor, symbol, name]
     *             properties:
     *               si:
     *                 type: string
     *               basesi:
     *                 type: string
     *               basesifactor:
     *                 type: number
     *               symbol:
     *                 type: string
     *               name:
     *                 type: string
     *             example:
     *               si: l
     *               basesi: l
     *               basesifactor: 1
     *               symbol: L
     *               name: Liter
     *     responses:
     *       200:
     *         description: Upserted unit
     *         content:
     *           application/json:
     *             schema:
     *               type: object
     *               properties:
     *                 unit:
     *                   $ref: '#/components/schemas/Unit'
     *       400:
     *         description: Invalid unit 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'
     *   delete:
     *     tags: [Unit]
     *     summary: Delete unit
     *     description: Deletes `si` for the selected company. Fails with `Unit in use` if articles still reference it.
     *     security:
     *       - cookieAuth: []
     *     x-markdown: unit/delete.md
     *     parameters:
     *       - in: query
     *         name: si
     *         required: true
     *         schema:
     *           type: string
     *     responses:
     *       204:
     *         description: Deleted
     *       400:
     *         description: Missing si 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 or unit not found
     *         content:
     *           application/json:
     *             schema:
     *               $ref: '#/components/schemas/Error'
     *       409:
     *         description: Unit in use
     *         content:
     *           application/json:
     *             schema:
     *               $ref: '#/components/schemas/Error'
     */
    // #region GET /unit

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

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

    // #endregion

    // #region PUT /unit

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

        const { si, basesi, basesifactor, symbol, name } = req.body ?? {};

        try {
            const unit = await db.upsert(req.user.id, {
                si,
                basesi,
                basesifactor,
                symbol,
                name,
            });
            res.status(200).json({ unit });
        } catch (error) {
            const status = unitErrorStatus(error);
            if (status === 500) console.error('Upsert unit failed:', error);
            res.status(status).json({ error: error.message });
        }
    });

    // #endregion

    // #region DELETE /unit

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

        const si = typeof req.query.si === 'string' ? req.query.si.trim() : '';
        if (!si) {
            return res.status(400).json({ error: 'si is required' });
        }

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

    // #endregion
}