import os
from os import path
from uuid import uuid4
import copy
from os import path
import sys

from bs4 import BeautifulSoup
import vcdvcd
from flask import Flask, redirect, url_for, abort, send_file, render_template, request, flash, Response
from werkzeug.utils import secure_filename

app = Flask(__name__)
app.config['MAX_CONTENT_LENGTH'] = 100 * 1000
app.config.from_envvar('VCD8SEG_SETTINGS')


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

@app.route('/show/<uuid:uuid>')
def show(uuid):
    uuid = str(uuid)
    fp = path.join(app.config['UPLOAD_PATH'], secure_filename(uuid))
    if not path.isfile(fp):
        abort(404)

    return send_file(fp, mimetype='image/svg+xml')

@app.route('/upload', methods=['POST'])
def upload_vcd():
    if not (file := request.files.get('file')):
        flash('Request is missing file part.')
        return redirect(url_for('index'))
    
    if file.filename == '':
        flash('No file selected.')
        return redirect(url_for('index'))

    if path.splitext(file.filename)[1].lower() != '.vcd':
        flash('Please upload a .vcd waveform file (not e.g. .v or .vvp)')
        return redirect(url_for('index'))

    uuid = str(uuid4())
    fp = path.join(app.config['UPLOAD_PATH'], secure_filename(uuid))
    file.save(fp)
    return redirect(url_for('vcd_setup', uuid=uuid))


@app.route('/setup/<uuid:uuid>', methods=['GET', 'POST'])
def vcd_setup(uuid):
    uuid = str(uuid)
    fp = path.join(app.config['UPLOAD_PATH'], secure_filename(uuid))
    if not path.isfile(fp):
        abort(404)
    with open(fp) as f:
        vcd = f.read()

    if request.method == 'GET':
        default_signal, signal_names = vcd_signal_names(vcd)
        return render_template('setup.html', uuid=uuid, signal_names=signal_names, default_signal=default_signal)

    else: # request.method == 'POST'
        try:
            svg = vcd_to_8seg_svg(vcd, request.form['signal'])
        except IndexError:
            abort(Response(400, 'Signal not found'))

        os.remove(path.join(app.config['UPLOAD_PATH'], secure_filename(uuid)))

        uuid = str(uuid4())
        fp = path.join(app.config['UPLOAD_PATH'], secure_filename(uuid))
        with open(fp, 'w') as f:
            f.write(svg)
        return redirect(url_for('show', uuid=uuid))


def vcd_signal_names(data):
    vcd = vcdvcd.VCDVCD(vcd_string=data)
    signal_names = list(vcd.references_to_ids.keys())
    default_signal = [*[n for n in signal_names if 'segments' in n],
                    *[n for n in signal_names if 'segs' in n],
                    *signal_names][0]
    return default_signal, signal_names


def vcd_to_8seg_svg(in_vcd, signal=None):
    with open(path.join(app.static_folder, '8seg-template.svg')) as f:
        soup = BeautifulSoup(f.read(), 'xml')

    (vb_x, vb_y, vb_w, vb_h) = list(map(int, soup.find('svg')['viewBox'].split()))

    display_template = soup.find(id='display').extract()

    def generate_digit(segments):
        inst = copy.copy(display_template)
        for seg, val in zip('abcdefgh', segments):
            if val:
                tag = inst.find(id=f'seg_{seg}')
                tag['style'] = tag['style'].replace('fill:#202040', 'fill:#ff0000')
        return inst

    def concat_digits(digits):
        inst = copy.copy(soup)
        svg = inst.find('svg')

        x, y = vb_x, vb_y
        w, h = 0, 0
        for i, segments in enumerate(digits):
            digit = generate_digit(segments)
            digit['id'] = f'digit{i}'
            digit['transform'] = f'translate({x}, {y})'
            svg.append(digit)

            x += vb_w
            w += vb_w
            h = vb_h

        w_phys = (i+1) * 15 # mm
        svg['viewBox'] = f'{vb_x} {vb_y} {w} {h}'
        svg['width'] = f'{w_phys}mm'
        svg['height'] = f'{15 * (vb_h / vb_w)}mm'
        return svg

    def parse_vcd(data, signal=None):
        vcd = vcdvcd.VCDVCD(vcd_string=data) # vcd? vcd vcd, vcd!

        signal_names = vcd.references_to_ids.keys()
        if signal is None:
            signal = [*[n for n in signal_names if 'segments' in n],
                    *[n for n in signal_names if 'segs' in n],
                    *signal_names][0]

        try:
            sig = vcd[signal]
        except IndexError:
            raise IndexError('Signal {signal} not found. Available signals: {", ".join(signal_names)}')

        # Only use first 10k rows
        for i, (time, value) in zip(range(10000), sig.tv):
            value = ('0' * int(sig.size) + value)[-int(sig.size):]
            yield [int(x) for x in value]

    return str(concat_digits(list(parse_vcd(in_vcd, signal))))