Verify result repository

Added a function to quickly verify a repository's mystery.

Please do NOT look at the code unless you already solved the mystery,
it'll just spoil the fun.

README.md

@@ -18,6 +18,13 @@ To generate a new repository at `/tmp/gitstery`:
 gitstery generate /tmp/gitstery
 ```
 
+To verify a repository:
+```
+gitstery verify /tmp/gitstery
+gitstery verify https://github.com/nivbend/gitstery.git
+gitstery verify git@github.com:nivbend/gitstery.git
+```
+
 If you have your own fork of the gitstery repository you'd like to update:
 ```
 gitstery push /tmp/gitstery <your repository URL>

setup.py

@@ -14,7 +14,7 @@
 
 setup(
     name='gitstery-generator',
-    version='0.21.0',
+    version='1.0.0',
     description='A Git murder mystery',
     long_description=Path('README.md').read_text(),
     long_description_content_type='text/markdown',

src/gitstery/cli.py

@@ -1,9 +1,13 @@
+import sys
 from os import environ, urandom
+from urllib.parse import urlparse
 from itertools import chain
 from pathlib import Path
+from contextlib import contextmanager, nullcontext
 from datetime import timedelta
 from random import seed, choice, choices, randrange
 from shutil import rmtree
+from tempfile import TemporaryDirectory
 from csv import DictWriter
 from inflect import engine
 from click import (Path as ClickPath, group, pass_context, argument, option, prompt, confirm, echo,
@@ -14,7 +18,14 @@
 from .fillers import random_people
 from .git_utils import git_commit
 from .phases import PHASES_COUNT, build_phase_1, build_phase_2, build_phase_3
-from .solution import build_solution
+from .solution import build_solution, verify_repository
+
+@contextmanager
+def clone_repository(url):
+    with TemporaryDirectory() as temporary_directory:
+        echo(f'Cloning {url} to {temporary_directory}')
+        cloned = Repo.clone_from(url, temporary_directory)
+        yield cloned
 
 @group()
 def cli():
@@ -176,3 +187,33 @@ def push(repo, url):
             echo(f'  {ref.local_ref} {summary}')
     finally:
         repo.delete_remote('origin')
+
+@cli.command()
+@argument('repository', envvar='GITSTERY_TARGET_REPO')
+def verify(repository):
+    """Verify a mystery REPOSITORY was built properly."""
+    uri = urlparse(repository)
+    if uri.scheme.lower() in ('http', 'https') or uri.path.startswith('git@'):
+        repo_context = clone_repository(repository)
+    else:
+        try:
+            # This also takes care of `file://` URIs.
+            repo_context = nullcontext(Repo(uri.path))
+        except:
+            echo(f'{repository}: Not a git repository')
+            sys.exit(1)
+
+    with repo_context as repo:
+        if 'master' != repo.head.ref.name:
+            echo('Checking out `master`')
+            repo.heads.master.checkout()
+
+        if repo.head.is_detached:
+            echo("Repository's head is detached")
+            sys.exit(1)
+        if repo.is_dirty():
+            echo('Repository is dirty')
+            sys.exit(1)
+
+        if not verify_repository(repo):
+            sys.exit(1)

src/gitstery/solution.py

@@ -1,5 +1,13 @@
+import re
+from datetime import datetime
+from subprocess import check_output
+from pathlib import Path
 from tempfile import NamedTemporaryFile
-from .people import SUSPECTS
+from click import echo, secho
+from .defines import (DATE_REPORT, DATE_REPORT_WEEK_START, DATE_REPORT_WEEK_END, POLICE_BRANCH,
+    ACCESS_POINT_OF_INTEREST)
+from .people import MAIN_DETECTIVE, SUSPECTS
+from .utils import rot13
 
 def build_solution(repo, addresses):
     # First we generate a hash for the solution to store as the contents of the `solution` tag.
@@ -20,3 +28,120 @@ def build_solution(repo, addresses):
         solution_ref = repo.git.hash_object('-w', solution.name)
 
     repo.create_tag('solution', ref=solution_ref)
+
+def verify_repository(repo):
+    ###  NOTE - SPOILER ALERT!!!!
+    # This function is used to verify the repository generated during development. If you haven't
+    # solved the mystery yet, don't spoil the way to the solution for yourself by reading it.
+    repo_root = Path(repo.working_tree_dir)
+    try:
+        (police_branch, ) = (branch for branch in repo.refs if branch.name.endswith(POLICE_BRANCH))
+    except ValueError as err:
+        echo(f'Missing police archive branch: {err}')
+        return False
+
+    try:
+        (detective_branch, ) = (branch for branch in repo.refs
+            if branch.name.endswith(f'detectives/{MAIN_DETECTIVE.username}'))
+    except ValueError as err:
+        echo(f"Missing main detective's branch: {err}")
+        return False
+
+    if not repo_root.joinpath('README.md').exists():
+        echo("Can't find 'README.md'")
+        return False
+    instructions = repo_root / 'instructions.txt'
+    if not instructions.exists():
+        echo(f"Can't find '{instructions.name}'")
+        return False
+    instructions_text = instructions.read_text()
+    if MAIN_DETECTIVE.name not in instructions_text:
+        echo(f"The main detective's name ({MAIN_DETECTIVE.name}) isn't in '{instructions.name}'")
+        return False
+    elif POLICE_BRANCH not in instructions_text:
+        echo(f"The policy branch name ({POLICE_BRANCH}) isn't in '{instructions.name}'")
+        return False
+
+    secho('Finding main report commit', fg='magenta')
+    regex_commit_log = re.compile('\n'.join([
+        r'commit [0-9a-f]+',
+        r'Author: +(.+) <.+>',
+        r'Date: +(.+)',
+        r'',
+        r'(.*)(?:\n((?: +.*\n*)+))?',
+    ]), re.MULTILINE)
+    commits = regex_commit_log.findall(repo.git.log(
+        '--since', f'{DATE_REPORT_WEEK_START:%d/%m/%Y}',
+        '--before', f'{DATE_REPORT_WEEK_END:%d/%m/%Y}',
+        '--author', f'{MAIN_DETECTIVE.name}',
+        police_branch))
+    if not commits:
+        echo('No commits match for main report')
+        return False
+    elif 1 < len(commits):
+        echo(f'Multiple commits ({len(commits)}) match main report')
+        return False
+    ((author, timestamp, title, main_report, ), ) = commits
+    timestamp = datetime.strptime(timestamp, '%a %b %d %H:%M:%S %Y %z').replace(tzinfo=None)
+    assert MAIN_DETECTIVE.name == author
+    assert 'Crime scene report' in title
+    assert DATE_REPORT == timestamp
+    assert ACCESS_POINT_OF_INTEREST in main_report
+    assert f'detectives/{MAIN_DETECTIVE.username}' in main_report
+
+    secho('Finding suspects in access log', fg='magenta')
+    commits = regex_commit_log.findall(repo.git.log(
+        f'-S{ACCESS_POINT_OF_INTEREST}',
+        detective_branch))
+    if not len(SUSPECTS) == len(commits):
+        echo(f'Expected number {len(SUSPECTS)} commits, got {len(commits)}')
+        return False
+    suspect_names = set(author for (author, _, _, _) in commits)
+    current_suspects = set(s.name for s in SUSPECTS)
+    assert current_suspects == suspect_names
+
+    secho("Finding suspects' addresses", fg='magenta')
+    addresses = []
+    regex_address = re.compile('^residents.txt:.+\t([0-9]+) (.+)$')
+    for suspect_name in suspect_names:
+        match = regex_address.match(repo.git.grep('-w', suspect_name, '--', 'residents.txt'))
+        if not match:
+            echo(f"Failed to find {suspect_name}'s address")
+            return False
+        (number, street_name, ) = match.groups()
+        addresses.append((suspect_name, street_name, int(number)))
+
+    secho('Interviewing suspects', fg='magenta')
+    lead = rot13('terra Ulhaqnv')
+    for (suspect_name, street_name, number) in addresses:
+        street_tag_name = street_name.lower().replace(' ', '_')
+        street_ref = f'street/{street_tag_name}~{number}'
+        (_, _, _, commit_msg) = regex_commit_log.match(repo.git.show('-s', street_ref)).groups()
+        if lead in commit_msg:
+            echo('  Got a lead by interviewing a suspect')
+            current_suspects.remove(suspect_name)
+            continue
+        investigate_ref = repo.git.show(f'{street_ref}:investigate')
+        investigation = repo.git.show(investigate_ref)
+        if lead not in investigation:
+            echo('  Suspect dropped due to lead')
+            current_suspects.remove(suspect_name)
+
+    try:
+        (suspect, ) = current_suspects
+    except ValueError:
+        echo(f"Couldn't reduce number of suspects ({len(current_suspects)})")
+        return False
+
+    secho('Checking suspect', fg='magenta')
+    solution_hash = check_output(
+        f'echo "{suspect}" | git hash-object --stdin',
+        cwd=repo_root,
+        shell=True,
+        universal_newlines=True)
+    if solution_hash.strip('\n') != repo.git.show('solution'):
+        echo('Found the wrong suspect!')
+        return False
+
+    secho('Good!', fg='green')
+    return True