import React, { useState, useMemo } from 'react';
import type { ProcessNode } from '../../types/process';
import { extractStreamInfo } from '../../utils/streamInfo';
import { exportProjectToCsv } from '../../utils/csvExport';

interface Props {
  processes: ProcessNode[];
  groups: number[][];
  groupNames: string[];
  groupCoordinates?: Record<string, { lat?: any; lon?: any; hours?: any }>;
}

type SortKey = 'group' | 'subprocess' | 'streamName' | 'type' | 'tin' | 'tout' | 'mdot' | 'cp' | 'CP' | 'Q' | 'lat' | 'lon' | 'hours' | 'water_in' | 'water_out' | 'density' | 'pressure' | 'notes';

export default function StreamDataTable({
  processes,
  groups = [],
  groupNames = [],
  groupCoordinates = {},
}: Props) {
  const [sortKey, setSortKey] = useState<SortKey>('Q');
  const [sortDir, setSortDir] = useState<'desc' | 'asc'>('desc');

  // Flatten streams
  const allRows = useMemo(() => {
    const res: any[] = [];
    groups.forEach((subIdxs, gIdx) => {
      const gName = groupNames[gIdx] || `Process ${gIdx + 1}`;
      const gCoord = groupCoordinates[gIdx] || {};
      subIdxs.forEach((si) => {
        const sub = processes[si];
        if (!sub) return;
        const baseInfo = {
          group: gName,
          subprocess: sub.name,
          lat: sub.lat || gCoord.lat || '',
          lon: sub.lon || gCoord.lon || '',
          hours: sub.hours || gCoord.hours || '',
          water_in: sub.extra_info?.water_content_in || '',
          water_out: sub.extra_info?.water_content_out || '',
          density: sub.extra_info?.density || '',
          pressure: sub.extra_info?.pressure || '',
          notes: sub.extra_info?.notes || '',
        };

        if (!(sub.streams || []).length && !(sub.children || []).some(c => (c.streams || []).length)) {
           res.push({ ...baseInfo, streamName: '', type: '', tin: null, tout: null, mdot: null, cp: null, CP: null, Q: null });
        }

        (sub.streams || []).forEach((s) => {
          const si = extractStreamInfo(s as any);
          res.push({ 
            ...baseInfo, 
            ...si, 
            streamName: s.name,
            // Prioritize stream-specific metadata if extracted
            water_in: si.water_in || baseInfo.water_in,
            water_out: si.water_out || baseInfo.water_out,
            density: si.density || baseInfo.density,
            pressure: si.pressure || baseInfo.pressure,
          });
        });
        (sub.children || []).forEach((child) => {
          const childBase = {
            group: gName,
            subprocess: `${sub.name} › ${child.name}`,
            lat: child.lat || sub.lat || gCoord.lat || '',
            lon: child.lon || sub.lon || gCoord.lon || '',
            hours: child.hours || sub.hours || gCoord.hours || '',
            water_in: child.extra_info?.water_content_in || sub.extra_info?.water_content_in || '',
            water_out: child.extra_info?.water_content_out || sub.extra_info?.water_content_out || '',
            density: child.extra_info?.density || sub.extra_info?.density || '',
            pressure: child.extra_info?.pressure || sub.extra_info?.pressure || '',
            notes: child.extra_info?.notes || sub.extra_info?.notes || '',
          };
          (child.streams || []).forEach((s) => {
            const si = extractStreamInfo(s as any);
            res.push({ 
              ...childBase, 
              ...si, 
              streamName: s.name,
              water_in: si.water_in || childBase.water_in,
              water_out: si.water_out || childBase.water_out,
              density: si.density || childBase.density,
              pressure: si.pressure || childBase.pressure,
            });
          });
        });
      });
    });
    return res;
  }, [processes, groups, groupNames]);

  const sortedRows = useMemo(() => {
    return [...allRows].sort((a, b) => {
      const vA = a[sortKey];
      const vB = b[sortKey];
      if (vA === vB) return 0;
      if (vA == null) return 1;
      if (vB == null) return -1;
      let res = (vA < vB ? -1 : 1);
      return sortDir === 'asc' ? res : -res;
    });
  }, [allRows, sortKey, sortDir]);

  const toggleSort = (key: SortKey) => {
    if (sortKey === key) setSortDir(sortDir === 'asc' ? 'desc' : 'asc');
    else { setSortKey(key); setSortDir('desc'); }
  };

  const cellStyle: React.CSSProperties = {
    padding: '4px 8px',
    fontSize: '11.5px',
    verticalAlign: 'middle',
    color: 'var(--text-main)',
    lineHeight: '1.2',
    borderBottom: '1px solid var(--border)',
    whiteSpace: 'nowrap',
    overflow: 'hidden',
    textOverflow: 'ellipsis',
    maxWidth: '200px'
  };
  const headStyle = (key: SortKey): React.CSSProperties => ({
    padding: '6px 8px',
    fontSize: '10.5px',
    fontWeight: 700,
    textTransform: 'uppercase',
    textAlign: 'left',
    background: 'var(--surface)',
    color: sortKey === key ? 'var(--primary)' : 'var(--text-muted)',
    cursor: 'pointer',
    borderBottom: '2px solid var(--border)',
    userSelect: 'none',
    whiteSpace: 'nowrap'
  });

  return (
    <div className="stream-data-table card mt-md" style={{ padding: 0, display: 'flex', flexDirection: 'column', height: '500px' }}>
      <div className="flex justify-between items-center" style={{ padding: '10px 12px 6px', flexShrink: 0 }}>
        <h4 style={{ fontSize: '11px', margin: 0, fontWeight: 700, textTransform: 'uppercase', color: 'var(--text-muted)' }}>
          Stream Data <span style={{ fontWeight: 400, opacity: 0.7, marginLeft: 8 }}>— Click header to sort</span>
        </h4>
        <button 
          className="btn btn-sm btn-primary" 
          onClick={() => exportProjectToCsv({
            processes,
            proc_groups: groups,
            proc_group_names: groupNames,
            proc_group_coordinates: groupCoordinates as any,
          } as any)}
          style={{ fontSize: '10px', padding: '2px 8px' }}
        >
          📄 Export CSV
        </button>
      </div>
      <div style={{ flex: 1, overflow: 'auto', borderTop: '1px solid var(--border)' }}>
        <table style={{ width: '100%', borderCollapse: 'collapse', tableLayout: 'auto' }}>
          <thead style={{ position: 'sticky', top: 0, zIndex: 1, boxShadow: '0 1px 2px rgba(0,0,0,0.05)' }}>
            <tr>
              {[
                {k:'group', l:'Process'}, {k:'subprocess', l:'Subprocess'}, 
                {k:'streamName', l:'Stream'}, {k:'type', l:'Type'}, 
                {k:'tin', l:'Tin'}, {k:'tout', l:'Tout'}, {k:'mdot', l:'ṁ'}, {k:'cp', l:'cp'}, {k:'CP', l:'CP'}, {k:'Q', l:'Q (kW)'},
                {k:'lat', l:'Lat'}, {k:'lon', l:'Lon'}, {k:'hours', l:'Hours'}, 
                {k:'water_in', l:'Water In'}, {k:'water_out', l:'Water Out'}, {k:'density', l:'Density'}, {k:'pressure', l:'Pressure'},
                {k:'notes', l:'Notes'},
              ].map(h => (
                <th key={h.k} style={headStyle(h.k as SortKey)} onClick={() => toggleSort(h.k as SortKey)}>
                  {h.l} {sortKey === h.k ? (sortDir === 'asc' ? '▴' : '▾') : ''}
                </th>
              ))}
            </tr>
          </thead>
          <tbody>
            {sortedRows.length === 0 ? (
              <tr><td colSpan={18} style={{ padding: 20, textAlign: 'center', color: 'var(--text-muted)' }}>No stream data found</td></tr>
            ) : (
              sortedRows.map((r, i) => (
                <tr key={i} style={{ background: i % 2 === 0 ? 'transparent' : 'var(--surface-hover)' }}>
                  <td style={cellStyle} title={r.group}>{r.group}</td>
                  <td style={cellStyle} title={r.subprocess}>{r.subprocess}</td>
                  <td style={cellStyle} title={r.streamName}>{r.streamName}</td>
                  <td style={cellStyle}>{r.type}</td>
                  <td style={cellStyle}>{r.tin?.toFixed(1) ?? '—'}</td>
                  <td style={cellStyle}>{r.tout?.toFixed(1) ?? '—'}</td>
                  <td style={cellStyle}>{r.mdot?.toFixed(2) ?? '—'}</td>
                  <td style={cellStyle}>{r.cp?.toFixed(2) ?? '—'}</td>
                  <td style={cellStyle}>{r.CP?.toFixed(2) ?? '—'}</td>
                  <td style={{ ...cellStyle, fontWeight: 700, color: 'var(--primary)' }}>{r.Q?.toFixed(1) ?? '—'}</td>
                  <td style={cellStyle}>{typeof r.lat === 'number' ? r.lat.toFixed(6) : r.lat}</td>
                  <td style={cellStyle}>{typeof r.lon === 'number' ? r.lon.toFixed(6) : r.lon}</td>
                  <td style={cellStyle}>{r.hours}</td>
                  <td style={cellStyle}>{r.water_in}</td>
                  <td style={cellStyle}>{r.water_out}</td>
                  <td style={cellStyle}>{r.density}</td>
                  <td style={cellStyle}>{r.pressure}</td>
                  <td style={{ ...cellStyle, fontStyle: 'italic', fontSize: '10.5px' }} title={r.notes}>{r.notes}</td>
                </tr>
              ))
            )}
          </tbody>
        </table>
      </div>
    </div>
  );
}