#!/usr/bin/python
"""Check Django template syntax.

usage::

    djlint INPUT -e <extension>

"""
import os
import re
import sys
from concurrent.futures import ProcessPoolExecutor
from pathlib import Path

import click
import yaml
from click import echo
from colorama import Fore, Style, deinit, init

rules = yaml.load(
    (Path(__file__).parent / "rules.yaml").read_text(encoding="utf8"),
    Loader=yaml.SafeLoader,
)


def lint_file(this_file: Path):
    """Check file for formatting errors."""
    file_name = str(this_file)
    errors: dict = {file_name: []}
    html = this_file.read_text(encoding="utf8")

    # build list of line ends for file
    line_ends = [m.end() for m in re.finditer(r"(?:.*\n)|(?:[^\n]+$)", html)]

    def get_line(start):
        """Get the line number and index of match."""
        for index, value in enumerate(line_ends):
            if value > start:
                line_start_index = (line_ends[index - 1] if index > 0 else 0) - 1
                return "%d:%d" % (index + 1, start - line_start_index)

        return "error"

    for rule in rules:
        rule = rule["rule"]

        for pattern in rule["patterns"]:
            for match in re.finditer(pattern, html, re.DOTALL):
                errors[file_name].append(
                    {
                        "code": rule["name"],
                        "line": get_line(match.start()),
                        "match": match.group()[:20].strip(),
                        "message": rule["message"],
                    }
                )

    return errors


def get_src(src: Path, extension=None):
    """Get source files."""
    if Path.is_file(src):
        return [src]

    # remove leading . from extension
    extension = extension[1:] if extension.startswith(".") else extension

    paths = list(src.glob(r"**/*.%s" % extension))

    if len(paths) == 0:
        echo(Fore.BLUE + "No files to lint! 😢")
        return []

    return paths


@click.command(context_settings={"help_option_names": ["-h", "--help"]})
@click.argument(
    "src",
    type=click.Path(
        exists=True, file_okay=True, dir_okay=True, readable=True, allow_dash=True
    ),
    nargs=1,
    metavar="SRC ...",
)
@click.option(
    "-e",
    "--extension",
    type=str,
    default="html",
    help="File extension to lint",
    show_default=True,
)
def main(src: str, extension: str):
    """Djlint django template files."""
    file_list = get_src(Path(src), extension)

    if len(file_list) == 0:
        return

    file_quantity = "%d file%s" % (len(file_list), ("s" if len(file_list) > 1 else ""))

    echo("\nChecking %s!" % file_quantity)

    worker_count = os.cpu_count()

    if sys.platform == "win32":
        # Work around https://bugs.python.org/issue26903
        worker_count = min(worker_count, 60)

    with ProcessPoolExecutor(max_workers=worker_count) as exe:
        file_errors = exe.map(lint_file, file_list)

    # format errors
    error_count = 0
    for error in file_errors:
        for this_file, errors in error.items():
            if errors:
                echo(
                    "{}\n{}\n{}===============================".format(
                        Fore.GREEN + Style.BRIGHT, this_file, Style.DIM
                    )
                    + Style.RESET_ALL
                )
                error_count += len(errors)
                for message in sorted(
                    errors, key=lambda x: int(x["line"].split(":")[0])
                ):
                    error = bool(message["code"][:1] == "E")
                    echo(
                        "{} {} {} {} {}".format(
                            (Fore.RED if error else Fore.YELLOW),
                            message["code"] + Style.RESET_ALL,
                            Fore.BLUE + message["line"] + Style.RESET_ALL,
                            message["message"],
                            Fore.BLUE + message["match"],
                        ),
                        err=False,
                    )

    success_message = "Checked %s, found %d errors." % (
        file_quantity,
        error_count,
    )

    echo("\n%s\n" % (success_message))


if __name__ == "__main__":
    init(autoreset=True)
    main()
    deinit()