@php
/**
 * @api-readonly
 * Returns developer team statistics from GitHub
 */
use Illuminate\Support\Facades\Http;
use Carbon\Carbon;

// Configuration
$token = env('GITHUB_TOKEN');
$repoStr = env('GITHUB_REPO'); // Expected format: "owner/repo"
// Filter Configuration:
// Commits with total line changes (additions + deletions) greater than this value 
// will have their line counts ignored in the stats (treated as 0 lines).
// This effectively bypasses vendor/node_modules dumps or massive removals.
$ignoredLinesThreshold = 5000; 

if (!$token || !$repoStr) {
    echo json_encode([
        'status' => 'error',
        'message' => 'GITHUB_TOKEN or GITHUB_REPO not set in .env'
    ]);
    exit;
}

$parts = explode('/', $repoStr);
if (count($parts) !== 2) {
    echo json_encode(['status' => 'error', 'message' => 'Invalid GITHUB_REPO format. Expected owner/repo']);
    exit;
}
$owner = $parts[0];
$name = $parts[1];

// GraphQL Query to fetch Commits
// This allows us to see authors even if they are not verified GitHub users (unlike stats/contributors)
$query = <<<GRAPHQL
query(\$owner: String!, \$name: String!, \$cursor: String) {
  repository(owner: \$owner, name: \$name) {
    defaultBranchRef {
      target {
        ... on Commit {
          history(first: 25, after: \$cursor) {
            pageInfo {
              hasNextPage
              endCursor
            }
            nodes {
              committedDate
              additions
              deletions
              author {
                name
                email
                user {
                  login
                  avatarUrl
                }
              }
            }
          }
        }
      }
    }
  }
}
GRAPHQL;

try {
    $allCommits = [];
    $cursor = null;
    $hasNextPage = true;
    $pageCount = 0;
    $maxPages = 20; // Fetch up to 1000 commits to avoid timeout

    while ($hasNextPage && $pageCount < $maxPages) {
        $response = Http::withToken($token)
            ->withHeaders([
                'User-Agent' => 'Laravel/10.0',
                'Accept' => 'application/json',
            ])
            ->post('https://api.github.com/graphql', [
            'query' => $query,
            'variables' => [
                'owner' => $owner,
                'name' => $name,
                'cursor' => $cursor
            ]
        ]);

        if ($response->failed()) {
            throw new Exception("GitHub API Error: " . $response->body());
        }

        $json = $response->json();
        
        if (isset($json['errors'])) {
            throw new Exception("GraphQL Error: " . json_encode($json['errors']));
        }

        $history = $json['data']['repository']['defaultBranchRef']['target']['history'] ?? null;
        
        if (!$history) {
            break;
        }

        $commits = $history['nodes'];
        $allCommits = array_merge($allCommits, $commits);
        
        $hasNextPage = $history['pageInfo']['hasNextPage'];
        $cursor = $history['pageInfo']['endCursor'];
        $pageCount++;
    }

    // Process Data
    $monthlyStats = [];
    $monthlyTotals = [];
    $totalCommitsProject = 0;

    foreach ($allCommits as $commit) {
        // Outlier Filter (Bypass Vendor/Large Changes)
        // If a commit changes more lines than the threshold, we ignore its line counts
        // but still count it as a commit activity.
        $totalChanges = $commit['additions'] + $commit['deletions'];
        if ($totalChanges > $ignoredLinesThreshold) {
            $commit['additions'] = 0;
            $commit['deletions'] = 0;
        }

        $date = Carbon::parse($commit['committedDate']);
        $monthKey = $date->format('Y-m');
        
        $authorData = $commit['author'];
        // Prefer GitHub Login, fallback to Git Author Name
        $authorName = $authorData['user']['login'] ?? $authorData['name'] ?? 'Unknown';
        
        // Grouping key
        $key = $authorName . '_' . $monthKey;

        // Initialize Monthly Total for relative percentage
        if (!isset($monthlyTotals[$monthKey])) {
            $monthlyTotals[$monthKey] = 0;
        }
        $monthlyTotals[$monthKey]++;

        // Initialize Developer Stats
        if (!isset($monthlyStats[$key])) {
            $monthlyStats[$key] = [
                'author' => $authorName,
                'month' => $monthKey,
                'added' => 0,
                'deleted' => 0,
                'commits' => 0,
            ];
        }

        $monthlyStats[$key]['added'] += $commit['additions'];
        $monthlyStats[$key]['deleted'] += $commit['deletions'];
        $monthlyStats[$key]['commits']++;
        
        $totalCommitsProject++;
    }

    // Calculate percentages and format for DevExtreme
    $resultData = array_values($monthlyStats);
    
    // Sort by month descending
    usort($resultData, function($a, $b) {
        return strcmp($b['month'], $a['month']);
    });

    // Add percentages
    foreach ($resultData as &$item) {
        // Global contribution percentage
        $item['percentage'] = $totalCommitsProject > 0 ? round(($item['commits'] / $totalCommitsProject) * 100, 2) : 0;
        
        // Monthly relative contribution percentage
        $monthTotal = $monthlyTotals[$item['month']] ?? 0;
        $item['monthly_percentage'] = $monthTotal > 0 ? round(($item['commits'] / $monthTotal) * 100, 2) : 0;
    }

    echo json_encode([
        'status' => 'success',
        'data' => $resultData,
        'meta' => [
            'repo' => $repoStr,
            'total_commits' => $totalCommitsProject,
            'fetched_commits' => count($allCommits),
            'ignored_threshold' => $ignoredLinesThreshold
        ]
    ], JSON_UNESCAPED_UNICODE);

} catch (Exception $e) {
    echo json_encode([
        'status' => 'error',
        'message' => $e->getMessage()
    ], JSON_UNESCAPED_UNICODE);
}
@endphp