import json
import math
import os
import StringIO
import subprocess
import tempfile
import time

import cairo
import flask
import pango
import pangocairo

class App(flask.Flask):
    def __init__(self, *args, **kwargs):
        super(App, self).__init__(*args, **kwargs)
        self.last = 0
        self.health = (0, False, "unknown")


app = App(__name__)

class Renderer(object):
    INCH_PER_MM = 0.039
    DPI = 300
    def __init__(self, size=(36,89)):
        width, height = [int(s * self.INCH_PER_MM * self.DPI) for s in size]
        surface = cairo.ImageSurface(cairo.FORMAT_ARGB32, width, height)
        context = cairo.Context(surface)

        # fill it white, while we're at it
        context.rectangle(0, 0, width, height)
        context.set_source_rgb(1, 1, 1)
        context.fill()

        context.translate(width, 0)
        context.rotate(math.pi/2)
        # yolo
        self.width, self.height = height, width

        self.context = context
        self.surface = surface

    def export_png(self, name):
        with open(name, 'w') as f:
            self.surface.write_to_png(f)

    def render_text(self, text, fontname, x, y, html=False):
        self.context.save()
        if y != -1:
            self.context.translate(x, y)

        pangocairo_context = pangocairo.CairoContext(self.context)
        pangocairo_context.set_antialias(cairo.ANTIALIAS_SUBPIXEL)
        layout = pangocairo_context.create_layout()
        layout.set_width(self.width*pango.SCALE)
        layout.set_alignment(pango.ALIGN_CENTER)

        if html:
            # Absolutely horrifying hack to fix broken text wrapping
            layout.set_markup('<span font_desc="%s">%s</span>' % (fontname, text))
        else:
            font = pango.FontDescription(fontname)
            layout.set_font_description(font)
            layout.set_text(text)

        if y == -1:
            self.context.translate(0, (self.height - layout.get_size()[1]/pango.SCALE)/2)

        self.context.set_source_rgb(0, 0, 0)
        pangocairo_context.update_layout(layout)
        pangocairo_context.show_layout(layout)

        self.context.restore()

@app.route('/')
def index():
    return flask.render_template('index.html')

def healthcheck():
    last_checked, last_status, last_details = app.health
    if time.time() - last_checked < 1:
        return last_status, last_details
    output = subprocess.check_output(['lpstat', '-p', '-d'])
    mark = False
    for line in output.split('\n'):
        line = line.strip()
        if line.startswith('printer DYMO_LabelWriter_450'):
            if 'is idle.' in line:
                return True, 'Idle'
            mark = True
            continue
        if mark:
            if line.startswith('Ready to print'):
                app.health = (time.time(), True, line)
                return True, line
            else:
                app.health = (time.time(), False, line)
                return False, line
        mark = False

@app.route('/health')
def health():
    ok, details = healthcheck()
    return json.dumps({'ok': ok, 'details': details})

@app.route('/stuff/preview/<int:size>/')
def stuff_preview(size):
    text = flask.request.args.get('text')
    html = flask.request.args.get('html') == '1'
    r = Renderer()
    r.render_text(text, 'Sans {}'.format(size), 0, -1, html)

    sio = StringIO.StringIO()
    r.surface.write_to_png(sio)
    sio.seek(0)
    return flask.send_file(sio, mimetype='image/png')

DELAY = 5
@app.route('/stuff/print/<int:size>/', methods=['POST'])
def stuff_print(size):
    if not healthcheck()[0]:
        return 'Printer is down.'
    last = app.last
    print last, time.time() - last
    if time.time() - last < DELAY:
        return 'Please wait {} more seconds before next print.'.format(int(DELAY - (time.time() - last)))
    text = flask.request.args.get('text')
    html = flask.request.args.get('html') == '1'
    r = Renderer()
    r.render_text(text, 'Sans {}'.format(size), 0, -1, html)
    path = '/tmp/hslabel'
    f = open(path, 'w')

    r.surface.write_to_png(f)
    f.flush()
    f.close()
    time.sleep(1)
    ex = 'lpr -P DYMO_LabelWriter_450 {}'.format(path)
    os.system(ex)

    f.close()
    app.last = time.time()
    return 'ok'

if __name__ == '__main__':
    app.run(debug=True)