'use strict';

const knex = require('../lib/knex');
const hasher = require('node-object-hash')();
const { enforce, filterObject } = require('../lib/helpers');
const dtHelpers = require('../lib/dt-helpers');
const interoperableErrors = require('../../shared/interoperable-errors');
const namespaceHelpers = require('../lib/namespace-helpers');
const shares = require('./shares');
const reports = require('./reports');
const files = require('./files');
const dependencyHelpers = require('../lib/dependency-helpers');

const allowedKeys = new Set(['name', 'description', 'type', 'data', 'html', 'text', 'namespace']);

function hash(entity) {
    return hasher.hash(filterObject(entity, allowedKeys));
}

async function getByIdTx(tx, context, id, withPermissions = true) {
    await shares.enforceEntityPermissionTx(tx, context, 'template', id, 'view');
    const entity = await tx('templates').where('id', id).first();
    entity.data = JSON.parse(entity.data);

    if (withPermissions) {
        entity.permissions = await shares.getPermissionsTx(tx, context, 'template', id);
    }

    return entity;
}

async function getById(context, id, withPermissions = true) {
    return await knex.transaction(async tx => {
        return await getByIdTx(tx, context, id, withPermissions);
    });
}

async function listDTAjax(context, params) {
    return await dtHelpers.ajaxListWithPermissions(
        context,
        [{ entityTypeId: 'template', requiredOperations: ['view'] }],
        params,
        builder => builder.from('templates').innerJoin('namespaces', 'namespaces.id', 'templates.namespace'),
        [ 'templates.id', 'templates.name', 'templates.description', 'templates.type', 'templates.created', 'namespaces.name' ]
    );
}

async function _validateAndPreprocess(tx, entity) {
    await namespaceHelpers.validateEntity(tx, entity);

    // We don't check contents of the "data" because it is processed solely on the client. The client generates the HTML code we use when sending out campaigns.

    entity.data = JSON.stringify(entity.data);
}

async function create(context, entity) {
    return await knex.transaction(async tx => {
        await shares.enforceEntityPermissionTx(tx, context, 'namespace', entity.namespace, 'createTemplate');

        await _validateAndPreprocess(tx, entity);

        const ids = await tx('templates').insert(filterObject(entity, allowedKeys));
        const id = ids[0];

        await shares.rebuildPermissionsTx(tx, { entityTypeId: 'template', entityId: id });

        return id;
    });
}

async function updateWithConsistencyCheck(context, entity) {
    await knex.transaction(async tx => {
        await shares.enforceEntityPermissionTx(tx, context, 'template', entity.id, 'edit');

        const existing = await tx('templates').where('id', entity.id).first();
        if (!existing) {
            throw new interoperableErrors.NotFoundError();
        }

        existing.data = JSON.parse(existing.data);

        const existingHash = hash(existing);
        if (existingHash !== entity.originalHash) {
            throw new interoperableErrors.ChangedError();
        }

        await _validateAndPreprocess(tx, entity);

        await namespaceHelpers.validateMove(context, entity, existing, 'template', 'createTemplate', 'delete');

        await tx('templates').where('id', entity.id).update(filterObject(entity, allowedKeys));

        await shares.rebuildPermissionsTx(tx, { entityTypeId: 'template', entityId: entity.id });
    });
}

async function remove(context, id) {
    await knex.transaction(async tx => {
        await shares.enforceEntityPermissionTx(tx, context, 'template', id, 'delete');

        await dependencyHelpers.ensureNoDependencies(tx, context, id, [
            {
                entityTypeId: 'campaign',
                query: tx => tx('template_dep_campaigns')
                    .where('template_dep_campaigns.template', id)
                    .innerJoin('campaigns', 'template_dep_campaigns.campaign', 'campaigns.id')
                    .select(['campaigns.id', 'campaigns.name'])
            }
        ]);

        await files.removeAllTx(tx, context, 'template', 'file', id);

        await tx('templates').where('id', id).del();
    });
}

module.exports.hash = hash;
module.exports.getByIdTx = getByIdTx;
module.exports.getById = getById;
module.exports.listDTAjax = listDTAjax;
module.exports.create = create;
module.exports.updateWithConsistencyCheck = updateWithConsistencyCheck;
module.exports.remove = remove;