import { WorkloadUser, LoadLevel } from '../services/workload'

interface WorkloadHeatmapProps {
  users: WorkloadUser[]
  weekStart: string
  weekEnd: string
  onUserClick: (userId: string, userName: string) => void
}

// Color mapping for load levels
const loadLevelColors: Record<LoadLevel, string> = {
  normal: '#4caf50',
  warning: '#ff9800',
  overloaded: '#f44336',
  unavailable: '#9e9e9e',
}

const loadLevelLabels: Record<LoadLevel, string> = {
  normal: 'Normal',
  warning: 'Warning',
  overloaded: 'Overloaded',
  unavailable: 'Unavailable',
}

export function WorkloadHeatmap({ users, weekStart, weekEnd, onUserClick }: WorkloadHeatmapProps) {
  const formatDate = (dateStr: string) => {
    const date = new Date(dateStr)
    return date.toLocaleDateString('zh-TW', { month: 'short', day: 'numeric' })
  }

  // Group users by department
  const groupedByDepartment = users.reduce((acc, user) => {
    const dept = user.department_name || 'No Department'
    if (!acc[dept]) {
      acc[dept] = []
    }
    acc[dept].push(user)
    return acc
  }, {} as Record<string, WorkloadUser[]>)

  const departments = Object.keys(groupedByDepartment).sort()

  if (users.length === 0) {
    return (
      <div style={styles.emptyState}>
        <p>No workload data available for this week.</p>
      </div>
    )
  }

  return (
    <div style={styles.container}>
      <div style={styles.header}>
        <span style={styles.weekRange}>
          {formatDate(weekStart)} - {formatDate(weekEnd)}
        </span>
        <div style={styles.legend}>
          {(Object.keys(loadLevelColors) as LoadLevel[]).map((level) => (
            <div key={level} style={styles.legendItem}>
              <span
                style={{
                  ...styles.legendColor,
                  backgroundColor: loadLevelColors[level],
                }}
              />
              <span style={styles.legendLabel}>{loadLevelLabels[level]}</span>
            </div>
          ))}
        </div>
      </div>

      <div style={styles.tableContainer}>
        <table style={styles.table}>
          <thead>
            <tr>
              <th style={styles.th}>Team Member</th>
              <th style={styles.th}>Department</th>
              <th style={styles.th}>Allocated</th>
              <th style={styles.th}>Capacity</th>
              <th style={styles.th}>Load</th>
              <th style={styles.th}>Status</th>
            </tr>
          </thead>
          <tbody>
            {departments.map((dept) =>
              groupedByDepartment[dept].map((user, index) => (
                <tr
                  key={user.user_id}
                  style={{
                    ...styles.tr,
                    backgroundColor: index % 2 === 0 ? '#fff' : '#fafafa',
                  }}
                  onClick={() => onUserClick(user.user_id, user.user_name)}
                >
                  <td style={styles.td}>
                    <span style={styles.userName}>{user.user_name}</span>
                  </td>
                  <td style={styles.td}>
                    <span style={styles.department}>{user.department_name || '-'}</span>
                  </td>
                  <td style={styles.td}>
                    <span style={styles.hours}>{user.allocated_hours}h</span>
                  </td>
                  <td style={styles.td}>
                    <span style={styles.hours}>{user.capacity_hours}h</span>
                  </td>
                  <td style={styles.td}>
                    <div style={styles.loadBarContainer}>
                      <div
                        style={{
                          ...styles.loadBar,
                          width: `${Math.min(user.load_percentage, 100)}%`,
                          backgroundColor: loadLevelColors[user.load_level],
                        }}
                      />
                      <span style={styles.loadPercentage}>{user.load_percentage}%</span>
                    </div>
                  </td>
                  <td style={styles.td}>
                    <span
                      style={{
                        ...styles.statusBadge,
                        backgroundColor: loadLevelColors[user.load_level],
                      }}
                    >
                      {loadLevelLabels[user.load_level]}
                    </span>
                  </td>
                </tr>
              ))
            )}
          </tbody>
        </table>
      </div>
    </div>
  )
}

const styles: { [key: string]: React.CSSProperties } = {
  container: {
    backgroundColor: 'white',
    borderRadius: '8px',
    boxShadow: '0 1px 3px rgba(0, 0, 0, 0.1)',
    overflow: 'hidden',
  },
  header: {
    display: 'flex',
    justifyContent: 'space-between',
    alignItems: 'center',
    padding: '16px 20px',
    borderBottom: '1px solid #eee',
  },
  weekRange: {
    fontSize: '14px',
    color: '#666',
    fontWeight: 500,
  },
  legend: {
    display: 'flex',
    gap: '16px',
  },
  legendItem: {
    display: 'flex',
    alignItems: 'center',
    gap: '6px',
  },
  legendColor: {
    width: '12px',
    height: '12px',
    borderRadius: '3px',
  },
  legendLabel: {
    fontSize: '12px',
    color: '#666',
  },
  tableContainer: {
    overflowX: 'auto',
  },
  table: {
    width: '100%',
    borderCollapse: 'collapse',
  },
  th: {
    textAlign: 'left',
    padding: '12px 16px',
    fontSize: '12px',
    fontWeight: 600,
    color: '#666',
    textTransform: 'uppercase',
    letterSpacing: '0.5px',
    backgroundColor: '#f5f5f5',
    borderBottom: '1px solid #eee',
  },
  tr: {
    cursor: 'pointer',
    transition: 'background-color 0.15s ease',
  },
  td: {
    padding: '14px 16px',
    fontSize: '14px',
    borderBottom: '1px solid #eee',
  },
  userName: {
    fontWeight: 500,
    color: '#333',
  },
  department: {
    color: '#666',
  },
  hours: {
    fontFamily: 'monospace',
    fontSize: '13px',
  },
  loadBarContainer: {
    position: 'relative',
    width: '120px',
    height: '24px',
    backgroundColor: '#f0f0f0',
    borderRadius: '4px',
    overflow: 'hidden',
  },
  loadBar: {
    position: 'absolute',
    top: 0,
    left: 0,
    height: '100%',
    borderRadius: '4px',
    transition: 'width 0.3s ease',
  },
  loadPercentage: {
    position: 'absolute',
    top: '50%',
    left: '50%',
    transform: 'translate(-50%, -50%)',
    fontSize: '12px',
    fontWeight: 600,
    color: '#333',
    textShadow: '0 0 2px rgba(255, 255, 255, 0.8)',
  },
  statusBadge: {
    display: 'inline-block',
    padding: '4px 10px',
    borderRadius: '4px',
    fontSize: '12px',
    fontWeight: 500,
    color: 'white',
  },
  emptyState: {
    textAlign: 'center',
    padding: '48px',
    color: '#666',
    backgroundColor: 'white',
    borderRadius: '8px',
    boxShadow: '0 1px 3px rgba(0, 0, 0, 0.1)',
  },
}

export default WorkloadHeatmap