# Copyright (C) 2021 The Qt Company Ltd.
# Contact: https://www.qt.io/licensing/
#
# You may use this file under the terms of the CC0 license.
# See the file LICENSE.CC0 from this package for details.

import argparse
import logging
import os
import re
import subprocess
import sys
from pathlib import Path

logging.basicConfig(level=logging.INFO)
log = logging.getLogger("get_data")


class cd:
    def __init__(self, path):
        self.path = path

    def __enter__(self):
        self.saved = os.getcwd()
        os.chdir(self.path)

    def __exit__(self, etype, value, traceback):
        os.chdir(self.saved)


def get_qt_modules(qt_path):
    def is_qt(x):
        valid_dir = (x.startswith("qt") or "pyside-setup" in x)
        return valid_dir and os.path.isdir(os.path.join(qt_path, x))
    return sorted([i for i in os.listdir(qt_path) if is_qt(i)])


def get_email_domain(x):
    x = x.replace('"', "")
    if x.count("@") == 0:
        try:
            v = x.split(".")[-2]
        except IndexError:
            v = ""
    else:
        v = ".".join(x.split("@")[1].split(".")[:-1]).replace("\\", "")

    if v in ("theqtcompany", "qt", "nokia", "nokiamail", "digia"):
        new_email = re.sub("@.*", "@qt.io", x)
        return new_email, "qt"
    return x, v


def process_git_log_line(line):
    changed = insertions = deletions = 0
    # files changed
    re_changed = re.search(r"(\d+) files? changed", line)
    if re_changed:
        changed = re_changed.group(1)
    # insertions
    re_insertions = re.search(r"(\d+) insertions?", line)
    if re_insertions:
        insertions = re_insertions.group(1)
    # deletions
    re_deletions = re.search(r"(\d+) deletions?", line)
    if re_deletions:
        deletions = re_deletions.group(1)

    original_line = line.split("‽")[0]
    # the last field is the 'email'
    original_email = original_line.split(";")[-1]
    email, domain = get_email_domain(original_email)

    return f'{original_line};"{email}";"{domain}";"{changed}";"{insertions}";"{deletions}"'


def git_log():
    def is_valid_line(x):
        if (
            x.strip()
            and "Qt by Nokia" not in x
            and "Qt Forward Merge Bot" not in x
            and "Qt Submodule Update Bot" not in x
        ):
            return True
        return False

    # We can do this process with:
    #   git log --all --no-merges --date=format:'%Y-%m-%d'
    #       --pretty=format:'µ"%cd";"%h";"%an";"%ce"'
    #       --shortstat | tr '\n' ' ' | tr 'µ' '\n' |
    #       sed 's/\ *\(\d+\)\ files\{0,1\}/\1/g'
    # But we will use only Python to perform those pipe operations.

    # This command has a trick to get the 'shortstats' on the same line
    # when processing the lines. Notice the 'µ' character that depicts the
    # beginning of the line. Additionally we use an interrobang '‽'
    # to depict the end of the git log, so we can add the 'files changed',
    # 'insertions', and 'deletions' at the end.
    o = subprocess.run(
        (
            "git log --all --no-merges "
            "--date=format:'%Y-%m-%d' "
            '--pretty=format:\'µ"%cd";"%h";"%an";"%ae"\'‽ '
            "--shortstat "
        ).split(),
        capture_output=True,
        universal_newlines=True,
        encoding="utf-8",
        errors="ignore",
    ).stdout
    o = o.replace("\n", " ").replace("µ", "\n").replace("'", "")
    return "\n".join(process_git_log_line(line) for line in o.splitlines() if is_valid_line(line))


def check_arguments(options):
    qt_path = Path(options.qt_dir)
    if qt_path.is_dir():
        return True
    log.error(f"'{qt_path}' is not a directory.")
    return False


def is_valid_module(m):
    if (m.name.startswith("qt") or str(m.name) in ("pyside-setup",)) and m.is_dir():
        return True
    return False


def process_qt_src(options):
    qt_path = Path(options.qt_dir)
    HEADER = "date;sha;name;original_email;email;domain;files_changed;insertions;deletions\n"
    for i in qt_path.glob("*"):
        if is_valid_module(i):
            log.info(f"Processing {i}...")
            output_csv = f"{Path(__file__).parent}/{i.name}.csv"
            out = None
            with cd(i):
                out = git_log()
            if not out:
                log.error("Empty 'git log' for i")
                continue
            with open(output_csv, "w") as f:
                f.write(HEADER)
                f.write(out)


if __name__ == "__main__":
    parser = argparse.ArgumentParser(prog="get_data")

    parser.add_argument(
        "--qt",
        action="http://code.qt.io/store",
        dest="qt_dir",
        required=True,
        help="Path to a directory containing Qt modules, like the 'qt5' meta repository",
    )

    options = parser.parse_args()
    if not check_arguments(options):
        parser.print_help()
        sys.exit(-1)

    # main process
    process_qt_src(options)