#!/usr/bin/env python3

import sys
import struct

import yaml
from intelhex import IntelHex


def as_fxp(v):
    return int(v * 2**16 + 0.5)

BASE_ADDR = 0x08080000

FLAG_NAME_TO_BIT_INDEX = {
        'USE_DCDC_CONTROL':    0
    }

CONFIG_KEY_TO_OFFSET = {
        # note: flags are at 0x0000, but not listed here due to special handling.
        'CORRIDOR_MIN_TEMPERATURE': 0x0004,
        'CORRIDOR_MAX_TEMPERATURE': 0x0008,
        'FAN_START_TEMPERATURE':    0x000C,
        'FAN_OFF_TEMPERATURE':      0x0010,
        'EMERGENCY_TEMPERATURE':    0x0014,
        'DUTY_CYCLE_MIN':           0x0018,
        'DUTY_CYCLE_MAX':           0x001C,
        'DUTY_CYCLE_START':         0x0020,
        'GAIN_T_HIGH_P':            0x0024,
        'GAIN_T_HIGH_I':            0x0028,
        'GAIN_T_LOW_P':             0x002C,
        'GAIN_T_LOW_I':             0x0030,
    }


if __name__ == "__main__":
    output = IntelHex()

    if len(sys.argv) < 3:
        print(f"usage: {sys.argv[0]} <yaml-config> <output-hex>")
        sys.exit(1)

    with open(sys.argv[1], 'r') as configfile:
        config = yaml.safe_load(configfile)

    flags = 0
    for key, bitidx in FLAG_NAME_TO_BIT_INDEX.items():
        if config['flags'][key]:
            flags |= (1 << bitidx)


    enc_bytes = struct.pack('<I', flags)
    output.puts(BASE_ADDR + 0x0000, enc_bytes)

    for key, offset in CONFIG_KEY_TO_OFFSET.items():
        value = as_fxp(config['config'][key])
        enc_bytes = struct.pack('<i', value)
        output.puts(BASE_ADDR + offset, enc_bytes)

    output.write_hex_file(sys.argv[2])