"""Helper functions for commands.
"""
import os
import sys
import json
import shutil
from itertools import islice
from pathlib import Path

from milc import cli
import jsonschema

from qmk.constants import KEYBOARD_OUTPUT_PREFIX
from qmk.json_schema import json_load, validate


def _find_make():
    """Returns the correct make command for this environment.
    """
    make_cmd = os.environ.get('MAKE')

    if not make_cmd:
        make_cmd = 'gmake' if shutil.which('gmake') else 'make'

    return make_cmd


def create_make_target(target, dry_run=False, parallel=1, **env_vars):
    """Create a make command

    Args:

        target
            Usually a make rule, such as 'clean' or 'all'.

        dry_run
            make -n -- don't actually build

        parallel
            The number of make jobs to run in parallel

        **env_vars
            Environment variables to be passed to make.

    Returns:

        A command that can be run to make the specified keyboard and keymap
    """
    env = []
    make_cmd = _find_make()

    for key, value in env_vars.items():
        env.append(f'{key}={value}')

    return [make_cmd, *(['-n'] if dry_run else []), *get_make_parallel_args(parallel), *env, target]


def create_make_command(keyboard, keymap, target=None, dry_run=False, parallel=1, **env_vars):
    """Create a make compile command

    Args:

        keyboard
            The path of the keyboard, for example 'plank'

        keymap
            The name of the keymap, for example 'algernon'

        target
            Usually a bootloader.

        dry_run
            make -n -- don't actually build

        parallel
            The number of make jobs to run in parallel

        **env_vars
            Environment variables to be passed to make.

    Returns:

        A command that can be run to make the specified keyboard and keymap
    """
    make_args = [keyboard, keymap]

    if target:
        make_args.append(target)

    return create_make_target(':'.join(make_args), dry_run=dry_run, parallel=parallel, **env_vars)


def get_make_parallel_args(parallel=1):
    """Returns the arguments for running the specified number of parallel jobs.
    """
    parallel_args = []

    if int(parallel) <= 0:
        # 0 or -1 means -j without argument (unlimited jobs)
        parallel_args.append('--jobs')
    else:
        parallel_args.append('--jobs=' + str(parallel))

    if int(parallel) != 1:
        # If more than 1 job is used, synchronize parallel output by target
        parallel_args.append('--output-sync=target')

    return parallel_args


def compile_configurator_json(user_keymap, bootloader=None, parallel=1, clean=False, **env_vars):
    """Convert a configurator export JSON file into a C file and then compile it.

    Args:

        user_keymap
            A deserialized keymap export

        bootloader
            A bootloader to flash

        parallel
            The number of make jobs to run in parallel

    Returns:

        A command to run to compile and flash the C file.
    """
    # In case the user passes a keymap.json from a keymap directory directly to the CLI.
    # e.g.: qmk compile - < keyboards/clueboard/california/keymaps/default/keymap.json
    user_keymap["keymap"] = user_keymap.get("keymap", "default_json")

    keyboard_filesafe = user_keymap['keyboard'].replace('/', '_')
    target = f'{keyboard_filesafe}_{user_keymap["keymap"]}'
    keyboard_output = Path(f'{KEYBOARD_OUTPUT_PREFIX}{keyboard_filesafe}')
    keymap_output = Path(f'{keyboard_output}_{user_keymap["keymap"]}')
    keymap_dir = keymap_output / 'src'
    keymap_json = keymap_dir / 'keymap.json'

    if clean:
        if keyboard_output.exists():
            shutil.rmtree(keyboard_output)
        if keymap_output.exists():
            shutil.rmtree(keymap_output)

    # begin with making the deepest folder in the tree
    keymap_dir.mkdir(exist_ok=True, parents=True)

    # Compare minified to ensure consistent comparison
    new_content = json.dumps(user_keymap, separators=(',', ':'))
    if keymap_json.exists():
        old_content = json.dumps(json.loads(keymap_json.read_text(encoding='utf-8')), separators=(',', ':'))
        if old_content == new_content:
            new_content = None

    # Write the keymap.json file if different
    if new_content:
        keymap_json.write_text(new_content, encoding='utf-8')

    # Return a command that can be run to make the keymap and flash if given
    verbose = 'true' if cli.config.general.verbose else 'false'
    color = 'true' if cli.config.general.color else 'false'
    make_command = [_find_make()]

    if not cli.config.general.verbose:
        make_command.append('-s')

    make_command.extend([
        *get_make_parallel_args(parallel),
        '-r',
        '-R',
        '-f',
        'builddefs/build_keyboard.mk',
    ])

    if bootloader:
        make_command.append(bootloader)

    for key, value in env_vars.items():
        make_command.append(f'{key}={value}')

    make_command.extend([
        f'KEYBOARD={user_keymap["keyboard"]}',
        f'KEYMAP={user_keymap["keymap"]}',
        f'KEYBOARD_FILESAFE={keyboard_filesafe}',
        f'TARGET={target}',
        f'KEYBOARD_OUTPUT={keyboard_output}',
        f'KEYMAP_OUTPUT={keymap_output}',
        f'MAIN_KEYMAP_PATH_1={keymap_output}',
        f'MAIN_KEYMAP_PATH_2={keymap_output}',
        f'MAIN_KEYMAP_PATH_3={keymap_output}',
        f'MAIN_KEYMAP_PATH_4={keymap_output}',
        f'MAIN_KEYMAP_PATH_5={keymap_output}',
        f'KEYMAP_JSON={keymap_json}',
        f'KEYMAP_PATH={keymap_dir}',
        f'VERBOSE={verbose}',
        f'COLOR={color}',
        'SILENT=false',
        'QMK_BIN="qmk"',
    ])

    return make_command


def parse_configurator_json(configurator_file):
    """Open and parse a configurator json export
    """
    user_keymap = json_load(configurator_file)
    # Validate against the jsonschema
    try:
        validate(user_keymap, 'qmk.keymap.v1')

    except jsonschema.ValidationError as e:
        cli.log.error(f'Invalid JSON keymap: {configurator_file} : {e.message}')
        exit(1)

    orig_keyboard = user_keymap['keyboard']
    aliases = json_load(Path('data/mappings/keyboard_aliases.hjson'))

    if orig_keyboard in aliases:
        if 'target' in aliases[orig_keyboard]:
            user_keymap['keyboard'] = aliases[orig_keyboard]['target']

        if 'layouts' in aliases[orig_keyboard] and user_keymap['layout'] in aliases[orig_keyboard]['layouts']:
            user_keymap['layout'] = aliases[orig_keyboard]['layouts'][user_keymap['layout']]

    return user_keymap


def build_environment(args):
    """Common processing for cli.args.env
    """
    envs = {}
    for env in args:
        if '=' in env:
            key, value = env.split('=', 1)
            envs[key] = value
        else:
            cli.log.warning('Invalid environment variable: %s', env)
    return envs


def in_virtualenv():
    """Check if running inside a virtualenv.
    Based on https://stackoverflow.com/a/1883251
    """
    active_prefix = getattr(sys, "base_prefix", None) or getattr(sys, "real_prefix", None) or sys.prefix
    return active_prefix != sys.prefix


def get_chunks(it, size):
    """Break down a collection into smaller parts
    """
    it = iter(it)
    return iter(lambda: tuple(islice(it, size)), ())


def dump_lines(output_file, lines, quiet=True):
    """Handle dumping to stdout or file
    Creates parent folders if required
    """
    generated = '\n'.join(lines) + '\n'
    if output_file and output_file.name != '-':
        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(generated, encoding='utf-8')

        if not quiet:
            cli.log.info(f'Wrote {output_file.name} to {output_file}.')
    else:
        print(generated)