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

// Configuration
$token = env('GITHUB_TOKEN');
$org = 'Truncgil-Techology';
$projectNumber = 2;

if (!$token) {
    echo json_encode(['status' => 'error', 'message' => 'GITHUB_TOKEN not set']);
    exit;
}

// GraphQL Query to fetch Project V2 items and fields
$query = <<<GRAPHQL
query {
  organization(login: "$org") {
    projectV2(number: $projectNumber) {
      title
      items(first: 100) {
        nodes {
          fieldValues(first: 20) {
            nodes {
              ... on ProjectV2ItemFieldSingleSelectValue {
                name
                field {
                  ... on ProjectV2FieldCommon {
                    name
                  }
                }
              }
              ... on ProjectV2ItemFieldUserValue {
                users(first: 5) {
                  nodes {
                    login
                    avatarUrl
                    name
                  }
                }
                field {
                  ... on ProjectV2FieldCommon {
                    name
                  }
                }
              }
            }
          }
          content {
            ... on Issue {
              title
              url
              state
              number
              createdAt
              updatedAt
              closedAt
            }
            ... on DraftIssue {
              title
              createdAt
              updatedAt
            }
            ... on PullRequest {
              title
              url
              state
              number
              createdAt
              updatedAt
              closedAt
            }
          }
        }
      }
    }
  }
}
GRAPHQL;

try {
    $response = Http::withToken($token)->post('https://api.github.com/graphql', [
        'query' => $query
    ]);

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

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

    $project = $data['data']['organization']['projectV2'] ?? null;
    
    if (!$project) {
        throw new Exception("Project not found or access denied.");
    }

    $items = $project['items']['nodes'];
    
    // Data structures for advanced analysis
    $developerStats = [];
    $timelineStats = [
        'weekly' => [],
        'monthly' => []
    ];
    $detailedItems = []; // Array for DataGrid
    
    $statusMapping = [
        'Done' => 'completed',
        'Ready' => 'active',
        'In progress' => 'active',
        'In review' => 'active',
        'Backlog' => 'pending',
        'No Status' => 'pending'
    ];

    foreach ($items as $item) {
        $status = 'No Status';
        $size = 'No Size';
        $assignees = [];

        // Parse Field Values
        foreach ($item['fieldValues']['nodes'] as $fieldValue) {
            if (!isset($fieldValue['field']['name'])) continue;

            $fieldName = $fieldValue['field']['name'];

            if ($fieldName === 'Status') {
                $status = $fieldValue['name'];
            } elseif ($fieldName === 'Size') {
                $size = $fieldValue['name'];
            } elseif ($fieldName === 'Assignees') {
                foreach ($fieldValue['users']['nodes'] as $user) {
                    $assignees[] = $user['login'];
                }
            }
        }

        if (empty($assignees)) {
            $assignees[] = 'Unassigned';
        }

        // Content details
        $content = $item['content'] ?? [];
        $title = $content['title'] ?? 'Untitled';
        $url = $content['url'] ?? '#';
        $state = $content['state'] ?? 'OPEN';
        
        $createdAt = $content['createdAt'] ?? null;
        $updatedAt = $content['updatedAt'] ?? null;
        $closedAt = $content['closedAt'] ?? null;
        
        // Determine completion date
        $completionDate = ($state === 'CLOSED' || $state === 'MERGED' || $status === 'Done') 
            ? ($closedAt ?? $updatedAt) 
            : null;

        $isCompleted = ($completionDate !== null);
        
        // Duration Calculation
        $duration = 'N/A';
        $durationSeconds = 0;

        if ($createdAt) {
             try {
                 $cStart = Carbon::parse($createdAt);
                 $endDateStr = $isCompleted ? $completionDate : $updatedAt;
                 if (!$endDateStr) $endDateStr = $createdAt; 

                 $cEnd = Carbon::parse($endDateStr);
                 
                 $diff = $cStart->diff($cEnd);
                 $parts = [];
                 if ($diff->y > 0) $parts[] = $diff->y . 'y';
                 if ($diff->m > 0) $parts[] = $diff->m . 'mo';
                 if ($diff->d > 0) $parts[] = $diff->d . 'd';
                 if ($diff->h > 0) $parts[] = $diff->h . 'h';
                 if (empty($parts) && $diff->i > 0) $parts[] = $diff->i . 'm';
                 if (empty($parts)) $parts[] = '0m';
                 
                 $duration = implode(' ', array_slice($parts, 0, 2));
                 $durationSeconds = $cStart->diffInSeconds($cEnd);

             } catch (Exception $e) {
                 $duration = 'Error';
             }
        }

        // Add to detailed items list (For DataGrid)
        $detailedItems[] = [
            'title' => $title,
            'status' => $status,
            'size' => $size,
            'assignees' => implode(', ', $assignees),
            'url' => $url,
            'duration' => $duration,
            'duration_seconds' => $durationSeconds,
            'created_at' => $createdAt ? Carbon::parse($createdAt)->format('Y-m-d H:i') : '-',
            'end_date' => $completionDate ? Carbon::parse($completionDate)->format('Y-m-d H:i') : '-'
        ];
        
        // Analyze for each assignee (For Charts/Cards)
        foreach ($assignees as $assignee) {
            if (!isset($developerStats[$assignee])) {
                $developerStats[$assignee] = [
                    'total_tasks' => 0,
                    'completed_tasks' => 0,
                    'active_tasks' => 0,
                    'pending_tasks' => 0,
                    'sizes' => [],
                    'completion_history' => [] 
                ];
            }

            $developerStats[$assignee]['total_tasks']++;
            
            $generalStatus = $statusMapping[$status] ?? 'active';
            
            if ($isCompleted) {
                $developerStats[$assignee]['completed_tasks']++;
                
                if ($completionDate) {
                    $cDate = Carbon::parse($completionDate);
                    $monthKey = $cDate->format('Y-m');
                    
                    if (!isset($developerStats[$assignee]['completion_history']['monthly'][$monthKey])) {
                        $developerStats[$assignee]['completion_history']['monthly'][$monthKey] = 0;
                    }
                    $developerStats[$assignee]['completion_history']['monthly'][$monthKey]++;
                }
            } else {
                 if ($generalStatus === 'active') {
                     $developerStats[$assignee]['active_tasks']++;
                 } else {
                     $developerStats[$assignee]['pending_tasks']++;
                 }
            }
            
            if (!isset($developerStats[$assignee]['sizes'][$size])) {
                $developerStats[$assignee]['sizes'][$size] = 0;
            }
            $developerStats[$assignee]['sizes'][$size]++;
        }
    }

    // Format Developer Stats for Frontend
    $performanceData = [];
    foreach ($developerStats as $assignee => $stats) {
        $performanceData[] = [
            'assignee' => $assignee,
            'total' => $stats['total_tasks'],
            'completed' => $stats['completed_tasks'],
            'active' => $stats['active_tasks'],
            'pending' => $stats['pending_tasks'],
            'completion_rate' => $stats['total_tasks'] > 0 ? round(($stats['completed_tasks'] / $stats['total_tasks']) * 100, 1) : 0,
            'sizes' => $stats['sizes'],
            'history' => $stats['completion_history']
        ];
    }
    
    // Format Timeline Data
    $timelineChartData = [];
    $allMonths = [];
    foreach ($developerStats as $assignee => $stats) {
        if (isset($stats['completion_history']['monthly'])) {
            $allMonths = array_merge($allMonths, array_keys($stats['completion_history']['monthly']));
        }
    }
    $allMonths = array_unique($allMonths);
    sort($allMonths);
    
    foreach ($allMonths as $month) {
        $row = ['month' => $month];
        foreach ($developerStats as $assignee => $stats) {
            $row[$assignee] = $stats['completion_history']['monthly'][$month] ?? 0;
        }
        $timelineChartData[] = $row;
    }

    echo json_encode([
        'status' => 'success',
        'project_title' => $project['title'],
        'developer_performance' => $performanceData,
        'timeline_chart' => $timelineChartData,
        'raw_items' => $detailedItems, // Restored this field for DataGrid
        'meta' => [
            'total_tasks' => count($items)
        ]
    ], JSON_UNESCAPED_UNICODE);

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