#!/usr/bin/env python3

import math
import time
import sqlite3
from datetime import datetime

import serial
import click

seg_map = {
        " ": 0x00,
        "a": 0x2e,
        "b": 0xd6,
        "c": 0xd0,
        "d": 0xc5,
        "e": 0x59,
        "f": 0x98,
        "g": 0xd4,
        "h": 0x8c,
        "i": 0x5c,
        "j": 0x78,
        "k": 0x8e,
        "l": 0xc0,
        "m": 0xa3,
        "n": 0xa5,
        "o": 0xf0,
        "p": 0x93,
        "q": 0xf4,
        "r": 0x9e,
        "s": 0x55,
        "t": 0xc8,
        "u": 0xe0,
        "v": 0x8a,
        "w": 0xac,
        "x": 0x0f,
        "y": 0x0b,
        "z": 0x5a,
        "0": 0x13,
        "1": 0x20,
        "2": 0x16,
        "3": 0x56,
        "4": 0x23,
        "5": 0x1c,
        "6": 0x4e,
        "7": 0x1a,
        "8": 0x5f,
        "9": 0x33,
        "/": 0x0a,
        "\\": 0x05,
        ".": 0x04,
        ",": 0x08,
        "_": 0x40,
        "!": 0x53,
        "?": 0x52,
        "*": 0x0f,
        ":": 0x50,
        "(": 0x06,
        "<": 0x06,
        "[": 0xd0,
        ")": 0x09,
        ">": 0x09,
        "]": 0x70,
        "|": 0x20,
        "#": 0xff,
    }


@click.command()
@click.option('-b', '--baudrate', type=int, default=9600)
@click.option('-w', '--display-width', type=int, default=32)
@click.option('-i', '--message-interval', type=float, default=30)
@click.argument('database')
@click.argument('port')
def cli(database, port, baudrate, message_interval, display_width):
    db = sqlite3.connect(database)
    ser = serial.Serial(port, baudrate)

    discard = 0
    while True:
        count, = db.execute('''
                SELECT COUNT(*) FROM messages
                WHERE suppress_display = 0 AND timestamp_displayed IS NULL
                ORDER BY timestamp_received''').fetchone()

        if count == 0:
            print(f'Queue is empty. Sleeping.')
            time.sleep(1)
            continue

        queue_pressure = max(0, min((math.log10(max(1, count-3)) - 0.3) * message_interval*2/3, message_interval*1/3))
        interval = message_interval - queue_pressure

        rowid, message, timestamp, remote_ip, suppress_display = db.execute('''
                SELECT rowid, message, timestamp_received, remote_ip, suppress_display FROM messages
                WHERE timestamp_displayed IS NULL
                ORDER BY timestamp_received LIMIT 1
                ''').fetchone()
        timestamp = datetime.fromisoformat(timestamp)
        delta = (datetime.utcnow() - timestamp).total_seconds()

        db.execute('UPDATE messages SET timestamp_displayed = datetime("now") WHERE rowid=?', (rowid,)) 
        db.commit()

        if suppress_display:
            discard += 1

        else:
            if discard > 0:
                print(f'Discarded {discard} messages.')
            discard = 0

            print(f'Queueing message by {remote_ip} received at {timestamp} ({delta//60:.0f}m {delta%60:.0f}s ago):')
            print('   ', repr(message))

            lines = [ line for line in message.splitlines() if line.strip() ]
            interval = max(5, interval/len(lines))
            for i, line in enumerate(lines):
                print(f'    [Line {i+1}/{len(lines)}] Waiting interval of {message_interval:.1f} s with queue pressure {queue_pressure:.1f} from n={count} items for a total of {interval:.1f} s')

                line = line.center(display_width)[:display_width]
                line_mapped = [seg_map.get(c, seg_map['#']) for c in line]
                formatted = ''.join(f'{d:02x}' for d in line_mapped) + '\n'
                time.sleep(interval)
                ser.write(formatted)
                ser.flush()


if __name__ == '__main__':
    cli()