keppler/lib/file.js

Real time code sharing for your lectures and presentations

// Depedencies
const diff = require('diff')
const ids = require('./ids.js')

class File
{
    constructor(_options)
    {
        // Set up
        this.id = ids.getId()
        this.name = _options.name
        this.path = {}
        this.path.directory = _options.path
        this.path.full = this.path.directory + '/' + this.name
        this.versions = []
        this.projectSocket = _options.projectSocket

        const nameParts = this.name.split('.')

        if(nameParts.length > 1)
        {
            this.extension = nameParts[ nameParts.length - 1 ]
        }
        else
        {
            this.extension = ''
        }

        // Create first version
        if(typeof _options.content !== 'undefined')
        {
            this.createVersion(_options.content)
        }
    }

    createVersion(content)
    {
        // Create version
        const version = {}
        const lastVersion = this.getLastVersion()

        version.date = new Date()
        version.content = content

        // First version
        if(!lastVersion)
        {
            version.addedLines = []
            version.removedLines = []
        }
        // No content
        else if(version.content === '')
        {
            version.addedLines = []
            version.removedLines = []

            // Don't save if last version had no content too
            if(lastVersion.content === '')
            {
                return false
            }
        }
        // Content
        else
        {
            const differences = diff.diffLines(
                lastVersion.content,
                version.content,
                {
                    // ignoreWhitespace: true
                }
            )

            // Set added lines
            version.addedLines = []

            let lineProgress = 0

            // Added lines and unchanged lines
            for(const differenceKey in differences)
            {
                const difference = differences[differenceKey]
                let lineBreaks = (difference.value.match(/\n/g) || []).length

                if(parseInt(differenceKey) === differences.length - 1)
                {
                    lineBreaks += 1
                }

                if(difference.added)
                {
                    for(let i = 0; i < lineBreaks; i++)
                    {
                        version.addedLines.push(lineProgress + i)
                    }
                }

                if(!difference.removed)
                {
                    lineProgress += lineBreaks
                }
            }

            // Set removed lines
            version.removedLines = []

            lineProgress = 0

            // Removed lines
            for(const differenceKey in differences)
            {
                const difference = differences[differenceKey]
                let lineBreaks = (difference.value.match(/\n/g) || []).length

                if(parseInt(differenceKey) === differences.length - 1)
                {
                    lineBreaks += 1
                }

                if(difference.removed)
                {
                    if(version.addedLines.indexOf(lineProgress) === -1 && version.addedLines.indexOf(lineProgress + 1) === -1)
                    {
                        version.removedLines.push(lineProgress)
                    }
                }

                if(!difference.removed)
                {
                    lineProgress += lineBreaks
                }
            }

            // No changed
            if(differences.length === 1 && lastVersion.content !== '')
            {
                return false
            }
        }

        // Emit
        this.projectSocket.emit('createVersion', { file: this.path.full, version })

        // Save
        this.versions.push(version)
    }

    getLastVersion()
    {
        if(this.versions.length === 0)
            return false

        return this.versions[ this.versions.length - 1 ]
    }

    describe()
    {
        // Set up
        const result = {}

        result.id        = this.id
        result.name      = this.name
        result.path      = this.path
        result.versions  = this.versions
        result.extension = this.extension

        return result
    }

    destructor()
    {

    }
}

module.exports = File