mantra.press/server/router/translate/index.js

const express = require('express')
const { Op } = require("sequelize")

module.exports = function (options) {
    const db = options.db;
    var router = express.Router();

    router.route('/:id')
        .get(function(request, response, next) {
            db.TranslationEntryVersion.findByPk(request.params.id, {
                include: [
                    {
                        association: db.TranslationEntryVersion.EntryVersion,
                        required: true,
                        include: [
                            {
                                association: db.EntryVersion.Chapters,
                                required: true,
                                limit: 1,
                                // TODO: Order by chapter index
                            }
                        ]
                    }
                ]
            }).then(translationEntryVersion => {
                if (translationEntryVersion) {
                    response.redirect(`/translate/${translationEntryVersion.id}/chapter/${translationEntryVersion.entryVersion.chapters[0].id}`)
                } else {
                    next()
                }
            })
        })

    router.route('/:id/chapter/:chapterId')
        .get(function(request, response, next) {
            db.Chapter.findByPk(request.params.chapterId, {
                include: [
                    {
                        association: db.Chapter.Chunks,
                        include: [
                            {
                                association: db.Chunk.Translation
                            }
                        ]
                    },
                    {
                        association: db.Chapter.EntryVersion,
                        required: true,
                        include: [
                            {
                                association: db.EntryVersion.TranslationEntryVersions,
                                required: true,
                                where: {
                                    id: request.params.id
                                }
                            },
                            {
                                association: db.EntryVersion.Entry,
                                include: [
                                    {
                                        association: db.Entry.Dialect
                                    }
                                ]
                            }
                        ]
                    }
                ]
            }).then(chapter => {
                if (chapter) {
                    response.display("translate-chapter", {
                        user: request.user,
                        pageTitle: `Translate Chapter ${chapter.name}`,
                        chapter: chapter 
                    })
                } else {
                    next()
                }
            }).catch(error => {
                next(error)
            })
        })

    router.route('/:id/chapter/:chapterId/t/:chunkIndex')
        .get(function(request, response, next) {
            const previousIndex = Number(request.params.chunkIndex)-1
            const nextIndex = Number(request.params.chunkIndex)+1
            db.Chunk.findAll({
                where: {
                    chapterId: request.params.chapterId,
                    index: {
                        [Op.between]: [
                            previousIndex, 
                            nextIndex
                        ],
                    }
                },
                limit: 3,
                include: [
                    {
                        association: db.Chunk.Translation
                    },
                    {
                        association: db.Chunk.Chapter,
                        required: true,
                        include: [
                            {
                                association: db.Chapter.EntryVersion,
                                required: true,
                                include: [
                                    {
                                        association: db.EntryVersion.TranslationEntryVersions,
                                        required: true,
                                        where: {
                                            id: request.params.id
                                        }
                                    },
                                    {
                                        association: db.EntryVersion.Entry,
                                        include: [
                                            {
                                                association: db.Entry.Dialect
                                            }
                                        ]
                                    }
                                ]
                            }
                        ]
                    }
                ]
            }).then(chunks => {
                if (chunks.length > 0) {
                    const chunk = chunks.find(chunk => chunk.index == Number(request.params.chunkIndex))
                    response.display("translate-chunk", {
                        user: request.user,
                        pageTitle: `Translate ${chunk.chapter.entryVersion.entry.name}`,
                        chunk: chunk,
                        previousChunk: chunks.find(chunk => chunk.index == previousIndex),
                        nextChunk: chunks.find(chunk => chunk.index == nextIndex)
                    })
                } else {
                    next()
                }
            }).catch(error => {
                next(error)
            })
        })
    return router;
};