# Copyright 2013-2019 Lawrence Livermore National Security, LLC and other
# Spack Project Developers. See the top-level COPYRIGHT file for details.
#
# SPDX-License-Identifier: (Apache-2.0 OR MIT)

import os
import re

import llnl.util.tty as tty
from llnl.util.lang import pretty_date
from llnl.util.filesystem import working_dir
from llnl.util.tty.colify import colify_table

import spack.paths
import spack.repo
from spack.util.executable import which
from spack.cmd import spack_is_git_repo


description = "show contributors to packages"
section = "developer"
level = "long"


def setup_parser(subparser):
    view_group = subparser.add_mutually_exclusive_group()
    view_group.add_argument(
        '-t', '--time', dest='view', action='store_const', const='time',
        default='time', help='sort by last modification date (default)')
    view_group.add_argument(
        '-p', '--percent', dest='view', action='store_const', const='percent',
        help='sort by percent of code')
    view_group.add_argument(
        '-g', '--git', dest='view', action='store_const', const='git',
        help='show git blame output instead of summary')

    subparser.add_argument(
        'package_name', help='name of package to show contributions for, '
        'or path to a file in the spack repo')


def blame(parser, args):
    # make sure this is a git repo
    if not spack_is_git_repo():
        tty.die("This spack is not a git clone. Can't use 'spack blame'")
    git = which('git', required=True)

    # Get name of file to blame
    blame_file = None
    if os.path.isfile(args.package_name):
        path = os.path.realpath(args.package_name)
        if path.startswith(spack.paths.prefix):
            blame_file = path

    if not blame_file:
        pkg = spack.repo.get(args.package_name)
        blame_file = pkg.module.__file__.rstrip('c')  # .pyc -> .py

    # get git blame for the package
    with working_dir(spack.paths.prefix):
        if args.view == 'git':
            git('blame', blame_file)
            return
        else:
            output = git('blame', '--line-porcelain', blame_file, output=str)
            lines = output.split('\n')

    # Histogram authors
    counts = {}
    emails = {}
    last_mod = {}
    total_lines = 0
    for line in lines:
        match = re.match(r'^author (.*)', line)
        if match:
            author = match.group(1)

        match = re.match(r'^author-mail (.*)', line)
        if match:
            email = match.group(1)

        match = re.match(r'^author-time (.*)', line)
        if match:
            mod = int(match.group(1))
            last_mod[author] = max(last_mod.setdefault(author, 0), mod)

        # ignore comments
        if re.match(r'^\t[^#]', line):
            counts[author] = counts.setdefault(author, 0) + 1
            emails.setdefault(author, email)
            total_lines += 1

    if args.view == 'time':
        rows = sorted(
            counts.items(), key=lambda t: last_mod[t[0]], reverse=True)
    else:  # args.view == 'percent'
        rows = sorted(counts.items(), key=lambda t: t[1], reverse=True)

    # Print a nice table with authors and emails
    table = [['LAST_COMMIT', 'LINES', '%', 'AUTHOR', 'EMAIL']]
    for author, nlines in rows:
        table += [[
            pretty_date(last_mod[author]),
            nlines,
            round(nlines / float(total_lines) * 100, 1),
            author,
            emails[author]]]

    table += [[''] * 5]
    table += [[pretty_date(max(last_mod.values())), total_lines, '100.0'] +
              [''] * 3]

    colify_table(table)
