# -*- coding: utf-8 -*-

import calendar
import difflib
import os
import shutil
import time
from code import CodeMetrics
from git import Repo


class RepositoryChecker:
    """Browse a Git repository."""


    def __init__(self, url, year):
        """Initialize the analysis of a Git repository."""

        self._repo = Repo(url)
        self._dump_path = url + '_dump'

        self._start = calendar.timegm(time.strptime('1/1/%u' % year, '%d/%m/%Y'))
        self._end = calendar.timegm(time.strptime('1/1/%u' % (year + 1), '%d/%m/%Y'))

        self._timeline = {}

        self._last_metrics = None

        self._insertions = 0
        self._deletions = 0

        self._added = 0
        self._removed = 0

        self._old = 0
        self._new = 0
        self._killed = 0


    def __str__(self):
        """Provide a pretty print of the checker."""

        desc = ''

        desc += '=== Code ===\n'
        desc += 'Insertions: %u\n' % self._insertions
        desc += 'Deletions:  %u\n' % self._deletions

        desc += '\n'

        desc += '=== Files ===\n'
        desc += 'Added:    %u\n' % self._added
        desc += 'Removed:  %u\n' % self._removed

        desc += '\n'

        desc += '=== TODO/FIXME ===\n'
        desc += 'Old:    %u\n' % self._old
        desc += 'New:    %u\n' % self._new
        desc += 'Killed: %u\n' % self._killed

        return desc


    def process(self):
        """Collect Git info."""

        selection = list(self._repo.iter_commits('master'))

        count = 0

        previous = None

        for commit in list(selection):

            valid = self._start <= commit.committed_date and commit.committed_date < self._end

            if not(previous or valid):
                continue

            elif previous and not(valid):
                break

            previous = commit

            count += 1

        i = 0

        previous = None

        for commit in list(selection):

            valid = self._start <= commit.committed_date and commit.committed_date < self._end

            if not(previous or valid):
                continue

            elif previous and not(valid):
                break

            previous = commit

            print('\r[+] Collecting Git info... %d%%' % ((i * 100) / count), end='')

            # Insertions / deletions

            total = commit.stats.total

            self._insertions += total.get('insertions', 0)

            self._deletions += total.get('deletions', 0)

            # The run command is :
            #
            #   git diff-tree SHA SHA~1 -r --abbrev=40 --full-index -M --raw --no-color
            #
            # Beware: all is reversed!

            for diff in commit.diff(commit.hexsha + '~1', create_patch=True, ignore_blank_lines=True, 
                                    ignore_space_at_eol=True, diff_filter='cr'):

                # Added / removed

                if diff.new_file:
                    self._removed += 1

                if diff.deleted_file:
                    self._added += 1

                # TODO / FIXME / REMME

                blob_a = None
                blob_b = None

                try:

                    if diff.a_blob:
                        blob_a = diff.a_blob.data_stream.read().decode('utf-8').splitlines(1)

                    if diff.b_blob:
                        blob_b = diff.b_blob.data_stream.read().decode('utf-8').splitlines(1)

                except UnicodeDecodeError:
                    pass

                if blob_a is None and blob_b is None:

                    # Binary file
                    pass

                elif blob_a is None:

                    for line in blob_b:

                        if 'TODO' in line or 'FIXME' in line or 'REMME' in line:

                            self._killed += 1

                elif blob_b is None:

                    for line in blob_a:

                        if 'TODO' in line or 'FIXME' in line or 'REMME' in line:

                            self._new += 1

                else:

                    for line in difflib.unified_diff(blob_a, blob_b):

                        if line.startswith('+++') or line.startswith('---'):
                            continue

                        if 'TODO' in line or 'FIXME' in line or 'REMME' in line:

                            if line.startswith('-'):
                                self._new += 1

                            elif line.startswith('+'):
                                self._killed += 1

            # Single lines of code

            progress = '\r[+] Collecting Git info... %d%%' % ((i * 100) / count)

            self._delete_dump()

            msg = self._build_dump(commit.tree, progress)

            print('\r' + ' ' * len(msg[1:]), end='')

            print(progress, end='')

            cm = CodeMetrics(self._dump_path)

            msg = cm.process(progress)

            print('\r' + ' ' * len(msg[1:]), end='')

            print(progress, end='')

            self._timeline[commit.committed_date] = cm.count_all_lines()

            if self._last_metrics is None:

                self._last_metrics = cm

                # All remaining TODO / FIXME

                msg = self._grep_for_toto_fixme(commit.tree, progress)

                print('\r' + ' ' * len(msg[1:]), end='')

                print(progress, end='')

            i += 1

        print('\r[+] Collecting Git info... %d%%' % ((i * 100) / count))


    def _delete_dump(self):
        """Delete all dumped items."""

        if os.path.exists(self._dump_path):
            shutil.rmtree(self._dump_path)


    def _build_dump(self, tree, msg):
        """Dump all items from a commit tree."""

        if not os.path.exists(self._dump_path):
            os.makedirs(self._dump_path)

        count = len(list(tree.traverse()))

        i = 0

        for item in tree.traverse():

            print(msg + ' -> Dumping items... %d%%' % ((i * 100) / count), end='')

            path = os.path.join(self._dump_path, item.path)

            if item.type == 'tree':

                if not os.path.exists(path):
                    os.makedirs(path)

            elif item.type == 'blob':

                with open(path, 'wb') as out:

                    out.write(item.data_stream.read())

            i += 1

        msg = msg + ' -> Dumping items... %d%%' % ((i * 100) / count)

        print(msg, end='')

        return msg


    def _grep_for_toto_fixme(self, tree, msg):
        """Find all waiting TODO / FIXME markers."""

        count = len(list(tree.traverse()))

        i = 0

        for item in tree.traverse():

            print(msg + ' -> Searching for markers... %d%%' % ((i * 100) / count), end='')

            if item.type == 'blob':

                blob = None

                try:

                    blob = item.data_stream.read().decode('utf-8').splitlines(1)

                except UnicodeDecodeError:
                    pass

                if blob:

                    for line in blob:

                        if 'TODO' in line or 'FIXME' in line or 'REMME' in line:

                            self._old += 1

            i += 1

        msg = msg + ' -> Searching for markers... %d%%' % ((i * 100) / count)

        print(msg, end='')

        return msg


    def get(self, name):
        """Provide a memorized property."""

        return getattr(self, '_' + name)