var sys  = require('sys')
var fs   = require('fs')
var http = require('http')
var haml = require('hamljs');
var exec = require('child_process').exec

var argv = process.argv
var target = argv[2]
var parser = argv[3] || 'ruby'

if(!target){
    console.error('usage: ' + argv.join(' ') + ' <filename>')
    process.exit(1)
}

fs.stat(target, function(e, stat){
    if(e){ throw e }
    if(!stat.isFile()) {
        console.error(target + ' is not file.')
        process.exit(1)
    }

    fs.watchFile(target, { interval: 500 }, function(curr, prev){
        Parser[parser](target)
    })
})

var Parser = {
    ruby: function(target){
        var output = target.replace('.haml', '.html'),
            cmd = 'haml -f html5 --trace ' + target + ' ' + output

        exec(cmd, function (e, stdout, stderr) {
            if(e){ console.error(e) }
            console.log('updated ', output)
        })
    },

    hamljs: function(target){
        fs.readFile(target, 'utf8', function (e, text) {
            if(e){ throw e }

            try{
                var html = haml.render(text)

                var output = target.replace('.haml', '.html')
                fs.writeFile(output, html, function(e){
                    if(e){ throw e }
                    console.log('updated ', output)
                })
            }catch(e){
                console.error(e)
            }
        })
    }
}