"""This script generates the XAP protocol generated header to be compiled into QMK.
"""
import re
from fnvhash import fnv1a_32

from qmk.commands import get_git_version
from qmk.constants import GPL2_HEADER_C_LIKE, GENERATED_HEADER_C_LIKE
from qmk.xap.common import latest_xap_defs, route_conditions


def _append_route_defines(lines, container, container_id=None, route_stack=None):
    """Handles building the list of the XAP routes, combining parent and child names together, as well as the route number.
    """
    if route_stack is None:
        route_stack = [container]
    else:
        route_stack.append(container)

    route_name = '_'.join([r['define'] for r in route_stack])

    if container_id:
        lines.append(f'#define {route_name} {container_id}')

    if 'routes' in container:
        for route_id in container['routes']:
            route = container['routes'][route_id]
            _append_route_defines(lines, route, route_id, route_stack)

    route_stack.pop()


def _append_route_masks(lines, container, container_id=None, route_stack=None):
    """Handles creating the equivalent XAP route masks, for capabilities checks. Forces value of `0` if disabled in the firmware.
    """
    if route_stack is None:
        route_stack = [container]
    else:
        route_stack.append(container)

    route_name = '_'.join([r['define'] for r in route_stack])
    condition = route_conditions(route_stack)

    if container_id:
        if condition:
            lines.append('')
            lines.append(f'#if {condition}')

        lines.append(f'#define {route_name}_MASK (1ul << ({route_name}))')

        if condition:
            lines.append(f'#else  // {condition}')
            lines.append(f'#define {route_name}_MASK 0')
            lines.append(f'#endif  // {condition}')
            lines.append('')

    if 'routes' in container:
        for route_id in container['routes']:
            route = container['routes'][route_id]
            _append_route_masks(lines, route, route_id, route_stack)

    route_stack.pop()


def _append_route_capabilities(lines, container, container_id=None, route_stack=None):
    """Handles creating the equivalent XAP route masks, for capabilities checks. Forces value of `0` if disabled in the firmware.
    """
    if route_stack is None:
        route_stack = [container]
    else:
        route_stack.append(container)

    route_name = '_'.join([r['define'] for r in route_stack])

    if 'routes' in container:
        lines.append('')
        lines.append(f'#define {route_name}_CAPABILITIES (0 \\')

        if 'routes' in container:
            for route_id in container['routes']:
                route = container['routes'][route_id]
                route_stack.append(route)
                child_name = '_'.join([r['define'] for r in route_stack])
                lines.append(f'  | ({child_name}_MASK) \\')
                route_stack.pop()

        lines.append('  )')

    if 'routes' in container:
        for route_id in container['routes']:
            route = container['routes'][route_id]
            _append_route_capabilities(lines, route, route_id, route_stack)

    route_stack.pop()


def generate_header(output_file, keyboard):
    """Generates the XAP protocol header file, generated during normal build.
    """
    xap_defs = latest_xap_defs()

    # Preamble
    lines = [GPL2_HEADER_C_LIKE, GENERATED_HEADER_C_LIKE, '#pragma once', '']

    # Versions
    prog = re.compile(r'^(\d+)\.(\d+)\.(\d+)')
    b = prog.match(xap_defs['version'])
    lines.append(f'#define XAP_BCD_VERSION 0x{int(b.group(1)):02d}{int(b.group(2)):02d}{int(b.group(3)):04d}ul')
    b = prog.match(get_git_version())
    lines.append(f'#define QMK_BCD_VERSION 0x{int(b.group(1)):02d}{int(b.group(2)):02d}{int(b.group(3)):04d}ul')
    keyboard_id = fnv1a_32(keyboard)
    lines.append(f'#define XAP_KEYBOARD_IDENTIFIER 0x{keyboard_id:08X}ul')
    lines.append('')

    # Append the route and command defines
    _append_route_defines(lines, xap_defs)
    lines.append('')
    _append_route_masks(lines, xap_defs)
    lines.append('')
    _append_route_capabilities(lines, xap_defs)
    lines.append('')

    # Generate the full output
    xap_generated_inl = '\n'.join(lines)

    # Clean up newlines
    while "\n\n\n" in xap_generated_inl:
        xap_generated_inl = xap_generated_inl.replace("\n\n\n", "\n\n")

    if output_file:
        if output_file.name == '-':
            print(xap_generated_inl)
        else:
            output_file.parent.mkdir(parents=True, exist_ok=True)
            if output_file.exists():
                output_file.replace(output_file.parent / (output_file.name + '.bak'))
            output_file.write_text(xap_generated_inl)