#!/usr/bin/env python3
"""
Сбор данных о коммитах из всех веток репозитория с полным diff.
Сохраняет JSON в /app/hermes_data/git_reports/<repo>_data.json
"""

import os
import re
import sys
import json
import argparse
import subprocess
import tempfile
from datetime import datetime
from collections import defaultdict

REPORTS_BASE_DIR = "/app/hermes_data/git_reports"

def get_all_commits_with_diff(repo_url, since=None, until=None, max_diff_size=5000, max_commits=500):
    """
    Клонирует репозиторий, получает коммиты из всех веток через git log --all.
    Возвращает список коммитов с полями:
        sha, message, author, date, diff, files_changed, insertions, deletions, branches (list)
    """
    clone_dir = tempfile.mkdtemp(prefix='git_report_')
    try:
        subprocess.run(['git', 'clone', repo_url, clone_dir],
                       check=True, capture_output=True, text=True)
    except subprocess.CalledProcessError as e:
        print(f"Clone failed: {e.stderr}", file=sys.stderr)
        return []

    # Загружаем все ветки и теги
    try:
        subprocess.run(['git', '-C', clone_dir, 'fetch', '--all'],
                       check=True, capture_output=True, text=True)
    except subprocess.CalledProcessError as e:
        print(f"Fetch --all failed: {e.stderr}", file=sys.stderr)
        # продолжаем, возможно, ветки уже есть

    # Получаем список коммитов из всех веток (--all)
    log_args = ['git', '-C', clone_dir, 'log', '--all', '--pretty=format:%H|%an|%ai|%s']
    if since:
        log_args.append(f'--since={since.isoformat()}')
    if until:
        log_args.append(f'--until={until.isoformat()}')

    try:
        result = subprocess.run(log_args, capture_output=True, text=True, check=True)
        lines = result.stdout.strip().split('\n')
        if not lines or (len(lines) == 1 and not lines[0]):
            print("No commits found.", file=sys.stderr)
            subprocess.run(['rm', '-rf', clone_dir])
            return []
    except subprocess.CalledProcessError as e:
        print(f"git log --all failed: {e.stderr}", file=sys.stderr)
        subprocess.run(['rm', '-rf', clone_dir])
        return []

    # Для каждого коммита определим, в каких ветках он встречается
    # Сначала соберём все коммиты без информации о ветках
    commits_dict = {}
    commit_order = []
    for line in lines:
        if not line.strip():
            continue
        parts = line.split('|', 3)
        if len(parts) < 4:
            continue
        sha, author, date, subject = parts
        commits_dict[sha] = {
            'sha': sha[:8],
            'author': author,
            'date': date,
            'message': subject,
            'diff': '',
            'files_changed': [],
            'insertions': 0,
            'deletions': 0,
            'branches': []
        }
        commit_order.append(sha)

    # Получаем информацию о ветках для каждого коммита
    # Используем git branch --contains
    for sha in commit_order[:max_commits]:
        try:
            branch_proc = subprocess.run(
                ['git', '-C', clone_dir, 'branch', '-r', '--contains', sha],
                capture_output=True, text=True, check=True
            )
            branches = [b.strip() for b in branch_proc.stdout.split('\n') if b.strip()]
            # Добавляем также локальные ветки
            local_proc = subprocess.run(
                ['git', '-C', clone_dir, 'branch', '--contains', sha],
                capture_output=True, text=True, check=True
            )
            local_branches = [b.strip().lstrip('* ') for b in local_proc.stdout.split('\n') if b.strip()]
            all_branches = list(set(branches + local_branches))
            commits_dict[sha]['branches'] = all_branches
        except subprocess.CalledProcessError:
            commits_dict[sha]['branches'] = []

    # Теперь собираем diff и статистику для каждого коммита (ограничимся max_commits)
    commits = []
    for idx, sha in enumerate(commit_order):
        if idx >= max_commits:
            print(f"Reached max commits limit ({max_commits}), stopping.", file=sys.stderr)
            break
        commit = commits_dict[sha]

        # Получаем diff (с флагом -m для merge-коммитов)
        try:
            diff_proc = subprocess.run(
                ['git', '-C', clone_dir, 'show', '-m', '--patch', '--unified=3', sha],
                capture_output=True, text=True, check=True
            )
            diff_output = diff_proc.stdout
            if not diff_output.strip():
                diff_output = "(no diff content – possibly empty commit or merge commit without changes)"
        except subprocess.CalledProcessError as e:
            diff_output = f"(error getting diff: {e.stderr})"

        if len(diff_output) > max_diff_size:
            diff_output = diff_output[:max_diff_size] + "\n... (diff truncated)"
        commit['diff'] = diff_output

        # Получаем статистику
        try:
            stat_proc = subprocess.run(
                ['git', '-C', clone_dir, 'show', '--numstat', '--pretty=format:', sha],
                capture_output=True, text=True, check=True
            )
            stat_lines = stat_proc.stdout.strip().split('\n')
            insertions = 0
            deletions = 0
            files_changed = []
            for sl in stat_lines:
                if not sl.strip():
                    continue
                parts_stat = sl.split('\t')
                if len(parts_stat) >= 3:
                    add_str, del_str, fname = parts_stat[0], parts_stat[1], parts_stat[2]
                    if add_str != '-':
                        insertions += int(add_str)
                    if del_str != '-':
                        deletions += int(del_str)
                    files_changed.append(fname)
            commit['insertions'] = insertions
            commit['deletions'] = deletions
            commit['files_changed'] = files_changed
        except subprocess.CalledProcessError:
            commit['insertions'] = 0
            commit['deletions'] = 0
            commit['files_changed'] = []

        # Отладочный вывод
        print(f"Commit {commit['sha']}: diff size = {len(commit['diff'])} bytes, branches: {len(commit['branches'])}", file=sys.stderr)
        commits.append(commit)

    subprocess.run(['rm', '-rf', clone_dir])
    return commits

def main():
    parser = argparse.ArgumentParser()
    parser.add_argument('--repo-url', required=True)
    parser.add_argument('--since', help='YYYY-MM-DD')
    parser.add_argument('--until', help='YYYY-MM-DD')
    parser.add_argument('--max-diff-size', type=int, default=5000,
                        help='Max characters of diff per commit (default 5000)')
    parser.add_argument('--max-commits', type=int, default=500,
                        help='Max commits to process (default 500)')
    args = parser.parse_args()

    since = datetime.fromisoformat(args.since) if args.since else None
    until = datetime.fromisoformat(args.until) if args.until else None

    repo_name_match = re.search(r'([^/]+?)(?:\.git)?$', args.repo_url.rstrip('/'))
    repo_name = repo_name_match.group(1) if repo_name_match else "unknown"

    print(f"Analyzing {repo_name} (all branches)...", file=sys.stderr)
    commits = get_all_commits_with_diff(args.repo_url, since, until,
                                        args.max_diff_size, args.max_commits)

    data = {
        "repo": repo_name,
        "period": {
            "since": since.isoformat() if since else "full_history_start",
            "until": until.isoformat() if until else "full_history_end"
        },
        "commits": commits,
        "issues": []
    }

    os.makedirs(REPORTS_BASE_DIR, exist_ok=True)
    data_file = os.path.join(REPORTS_BASE_DIR, f"{repo_name}_data.json")
    with open(data_file, 'w', encoding='utf-8') as f:
        json.dump(data, f, ensure_ascii=False, indent=2)
    print(data_file)

if __name__ == '__main__':
    main()