"use strict";

var express = require('express')
var box0 = require('../lib/box0')
var util = require('util')

var dev = box0.usb.open_supported()
var dio0 = dev.dio()

var app = express()

function invalid_arg(res, msg) {
    res.set('Content-Type', 'text/plain')
    res.status(400).send(msg)
}

function handle_exception(res, cb) {
    try {
        cb();
    } catch (e) {
        res.set('Content-Type', 'text/plain')
        res.status(500).send(e.message)
    }
}

app.get('/', function (req, res) {
    res.json({
        name: dev.name,
        manuf: dev.manuf,
        serial: dev.serial
    })
})

app.get('/dio/0', function (req, res) {
    var low = dio0.ref.low.toFixed(6)
    var high = dio0.ref.high.toFixed(6)

    res.json({
        name: dio0.header.name,
        count: dio0.pin_count,
        ref: {low, high}
    })
})

app.param('pin', function(req, res, next, pin) {
    var pin_value = parseInt(pin)
    if (pin_value >= 0 && pin_value < dio0.pin_count) {
        req.pin = pin_value
        next()
        return
    }

    invalid_arg(res, util.format('Invalid pin "%s"', pin))
})

app.get('/dio/0/:pin', function (req, res) {
    handle_exception(res, function () {
        var pin = req.pin
        var name = dio0.label.pin[pin]
        if (name == null) {
            name = 'CH' + pin
        }

        var value = dio0.value_get(pin)
        var dir = dio0.dir_get(pin)
        var hiz = dio0.hiz_get(pin)

        value = {true: 'high', false: 'low'}[value]
        dir = {true: 'output', false: 'input'}[dir]
        hiz = {true: 'enabled', false: 'disabled'}[hiz]

        res.json({pin, name, value, dir, hiz})
    })
})

app.get('/dio/0/:pin/value', function (req, res) {
    handle_exception(res, function () {
        var pin = req.pin
        var value = dio0.value_get(pin)
        value = {true: 'high', false: 'low'}[value]
        res.json({pin, value})
    })
})

app.get('/dio/0/:pin/dir', function (req, res) {
    handle_exception(res, function () {
        var pin = req.pin
        var dir = dio0.dir_get(pin)
        dir = {true: 'output', false: 'input'}[dir]
        res.json({pin, dir})
    })
})

app.get('/dio/0/:pin/hiz', function (req, res) {
    handle_exception(res, function () {
        var pin = req.pin
        var hiz = dio0.hiz_get(pin)
        hiz = {true: 'enabled', false: 'disabled'}[hiz]
        res.json({pin, hiz})
    })
})

app.get('/dio/0/:pin/toggle', function (req, res) {
    handle_exception(res, function () {
        var pin = req.pin
        dio0.value_toggle(pin)
        res.json({pin})
    })
})

app.get('/dio/0/:pin/value/:value', function (req, res) {
    var pin = req.pin
    var value = String(req.params.value).toLowerCase()
    value = {'high': true, 'low': false}[value]

    if (value === undefined) {
        var msg = util.format('Invalid value "%s"', req.params.value)
        return invalid_arg(res, msg)
    }

    handle_exception(res, function () {
        dio0.value_set(pin, value)
        res.json({pin})
    })
})

app.get('/dio/0/:pin/dir/:value', function (req, res) {
    var pin = req.pin
    var value = String(req.params.value).toLowerCase()
    value = {'output': true, 'input': false}[value]

    if (value === undefined) {
        var msg = util.format('Invalid value "%s"', req.params.value)
        return invalid_arg(res, msg)
    }

    handle_exception(res, function () {
        dio0.dir_set(pin, value)
        res.json({pin})
    })
})

app.get('/dio/0/:pin/hiz/:value', function (req, res) {
    var pin = req.pin
    var value = String(req.params.value).toLowerCase()
    value = {'enable': true, 'disable': false}[value]

    if (value === undefined) {
        var msg = util.format('Invalid value "%s"', req.params.value)
        return invalid_arg(res, msg)
    }

    handle_exception(res, function () {
        dio0.hiz_set(pin, value)
        res.json({pin})
    })
})

app.listen(3000, function () {
    console.log('Listening on port 3000!')
    dio0.basic_prepare()
    dio0.basic_start()
})

process.on('SIGINT', function() {
    console.log("\nGracefully shutting down from SIGINT (Ctrl+C)")
    dio0.basic_stop()
    dio0.close()
    dev.close()
    process.exit(1)
})