import os
import subprocess
from tempfile import TemporaryDirectory

import buildconfig
import codegen
import mozpack.path as mozpath
from mozbuild.util import FileAvoidWrite


def WebCompatBuildTest(harness):
    mach_path = mozpath.join(buildconfig.topsrcdir, "mach")
    if not os.path.isfile(mach_path) or not os.access(mach_path, os.X_OK):
        raise ValueError("Could not find mach to run linter")
    webcompat_reldir = mozpath.join("browser", "extensions", "webcompat")
    webcompat_dir = mozpath.join(buildconfig.topsrcdir, webcompat_reldir)
    interventions_dir = mozpath.join(webcompat_dir, "data", "interventions")

    generated_filenames_list = mozpath.join(
        webcompat_dir, "preprocessed_intervention_files.mozbuild"
    )
    generated_files = []
    with open(generated_filenames_list) as fd:
        for line in fd.read().splitlines():
            if ".js" in line or ".css" in line:
                generated_files.append(line.strip()[1:-2])

    with TemporaryDirectory(dir=webcompat_dir) as to_lint_dir:
        for filename in generated_files:
            generated_path = mozpath.join(to_lint_dir, filename)
            with FileAvoidWrite(generated_path) as generated_fd:
                codegen.generate_file(generated_fd, interventions_dir)

        linting_result = subprocess.run(
            [mach_path, "lint", to_lint_dir],
            stdout=subprocess.PIPE,
            check=False,
            text=True,
        ).stdout

        # The output should look like this. We only care about the lines with [error]:
        # 0:06.85   0   error  An error occurred running prettier. Please check the following error messages:
        # 0:06.85
        # 0:06.85 [error] browser/extensions/webcompat/tmp6q8stvbu/bug1899930-africanews.com-hide_browser_notice.css: SyntaxError: CssSyntaxError: Unexpected } (1:56)
        # 0:06.85 [error] > 1 | #platform-detection-info { display: none !important; } }
        # 0:06.85 [error]     |                                                        ^  prettier (stylelint)
        # 0:06.85
        # 0:06.85 /full/path/to/build/browser/extensions/webcompat/tmp6q8stvbu/bug1575000-apply.lloydsbank.co.uk.json-fix_misaligned_radio_buttons.css
        # 0:06.85   0   error  No matching license strings found in tools/lint/license/valid-licenses.txt  (license)
        # 0:06.85   0   error  This file needs formatting with Prettier (use 'mach lint --fix <path>').    prettier (stylelint)
        # 0:06.85   1   error  File does not end with newline character                                    (file-whitespace)

        def parse_fragment_errors(linter_stdout):
            error_lines_for_current_file = None
            for line in linter_stdout.splitlines():
                if "[error]" not in line:
                    continue

                # we hit the next file being linted when we reach a line like this:
                # 0:09.50 [error] browser/extensions/webcompat/tmpumt4ocoj/bug1457335-histography.io.js: SyntaxError: Missing semicolon. (27:5)
                if webcompat_reldir in line:
                    if error_lines_for_current_file:
                        yield error_lines_for_current_file

                    [linted_filename, error] = line.split("[error]", maxsplit=1)[
                        1
                    ].split(":", maxsplit=1)
                    linted_filename = mozpath.splitext(
                        mozpath.basename(linted_filename)
                    )[0]
                    summary_line = (
                        f"Error linting generated file {linted_filename}: {error}"
                    )
                    error_lines_for_current_file = [summary_line]
                else:
                    error_lines_for_current_file.append(
                        line.split("[error] ", maxsplit=1)[1]
                    )

            if error_lines_for_current_file:
                yield "\n".join(error_lines_for_current_file)

        bad_fragments = list(parse_fragment_errors(linting_result))
        if not bad_fragments:
            harness.ok(True, "mach lint found no errors with generated files")
        else:
            for fragment_error in bad_fragments:
                harness.ok(False, fragment_error)