import React, { useState } from 'react'
import { useData } from '../DataContext.jsx'
import UploadModal from './UploadModal.jsx'

const LS_KEY = 'genesis_active_file'

export default function Header({ user, onLogout }) {
  const { stats, reload } = useData()
  const s = stats || {}
  const [uploadOpen, setUploadOpen] = useState(false)
  const [activeFile, setActiveFile] = useState(
    () => localStorage.getItem(LS_KEY) || ''
  )

  function handleSuccess(filename) {
    if (filename) {
      setActiveFile(filename)
      localStorage.setItem(LS_KEY, filename)
    }
    reload()
  }

  return (
    <>
      <header className="hdr">
        <div className="hdr-left">
          <img src="/dabur_logo.jpg" alt="Dabur" className="logo-d" />
          <div className="hdr-brand-txt">
            <div className="brand">{s.brand || 'Genesis AI'}</div>
            <div className="sub">Price Elasticity Intelligence · Genesis AI</div>
          </div>
          <img src="/genesis_logo.jpg" alt="Genesis AI" className="logo-g" />
        </div>
        <div className="hdr-right">

          {/* Active file display */}
          <div style={{
            display: 'flex', alignItems: 'center', gap: 7,
            background: activeFile ? 'rgba(26,107,47,.07)' : 'var(--sf)',
            border: `1px solid ${activeFile ? 'rgba(26,107,47,.25)' : 'var(--bd)'}`,
            borderRadius: 8, padding: '5px 11px',
            minWidth: 160, maxWidth: 280,
          }}>
            <span style={{ fontSize: 14, flexShrink: 0 }}>
              {activeFile ? '📄' : '📭'}
            </span>
            <div style={{ minWidth: 0 }}>
              <div style={{
                fontSize: 9, fontWeight: 600, letterSpacing: .5,
                color: activeFile ? 'var(--gn)' : 'var(--mt)',
                textTransform: 'uppercase', lineHeight: 1,
              }}>
                {activeFile ? 'Simulating' : 'No file loaded'}
              </div>
              {activeFile ? (
                <div style={{
                  fontSize: 10, color: 'var(--tx)', fontFamily: 'var(--mono)',
                  whiteSpace: 'nowrap', overflow: 'hidden', textOverflow: 'ellipsis',
                  maxWidth: 200, marginTop: 2, lineHeight: 1.2,
                }}>
                  {activeFile}
                </div>
              ) : (
                <div style={{ fontSize: 10, color: 'var(--mt)', marginTop: 2, lineHeight: 1.2 }}>
                  Upload an Excel file to begin
                </div>
              )}
            </div>
          </div>

          {/* Upload button — always visible */}
          <button
            onClick={() => setUploadOpen(true)}
            title={activeFile ? 'Replace current file' : 'Upload Excel file'}
            style={{
              display: 'flex', alignItems: 'center', gap: 5,
              background: activeFile ? 'var(--sf)' : 'var(--gn)',
              color: activeFile ? 'var(--gn)' : '#fff',
              border: activeFile ? '1px solid rgba(26,107,47,.4)' : 'none',
              borderRadius: 8,
              padding: '6px 13px', cursor: 'pointer',
              fontSize: 11, fontWeight: 600,
              boxShadow: activeFile ? 'none' : '0 1px 4px rgba(26,107,47,.25)',
              flexShrink: 0,
            }}>
            {activeFile ? '↑ Replace' : '↑ Upload'}
          </button>

          <div className="bdg">30 grains</div>
          {s.dab_cr_25 && (
            <div className="hdr-stat">
              <span className="val">₹{s.dab_cr_25?.toFixed(1)}Cr</span>
              <span className="lbl">2025 Value</span>
            </div>
          )}
          {s.vol_growth != null && (
            <div className="hdr-stat">
              <span className="val" style={{ color: s.vol_growth >= 0 ? 'var(--gn)' : 'var(--rd)' }}>
                {s.vol_growth >= 0 ? '+' : ''}{s.vol_growth?.toFixed(1)}%
              </span>
              <span className="lbl">Vol Growth</span>
            </div>
          )}
          {s.avg_own_e != null && (
            <div className="hdr-stat">
              <span className="val" style={{ color: 'var(--saf)' }}>{s.avg_own_e?.toFixed(2)}</span>
              <span className="lbl">Avg Own ε</span>
            </div>
          )}

          {/* Logged-in user + logout */}
          {user && (
            <div style={{
              display: 'flex', alignItems: 'center', gap: 8,
              borderLeft: '1px solid var(--bd)', paddingLeft: 12, marginLeft: 4,
            }}>
              <div style={{ textAlign: 'right' }}>
                <div style={{ fontSize: 11, fontWeight: 600, color: 'var(--tx)', lineHeight: 1.2 }}>
                  {user.name}
                </div>
                <div style={{ fontSize: 9, color: 'var(--mt)', lineHeight: 1.2 }}>
                  {user.email}
                </div>
              </div>
              <button
                onClick={onLogout}
                title="Sign out"
                style={{
                  background: 'var(--sf)', border: '1px solid var(--bd)',
                  borderRadius: 7, padding: '5px 10px',
                  fontSize: 11, fontWeight: 600, color: 'var(--mt)',
                  cursor: 'pointer', flexShrink: 0,
                }}>
                Sign out
              </button>
            </div>
          )}
        </div>
      </header>

      <UploadModal
        open={uploadOpen}
        onClose={() => setUploadOpen(false)}
        onSuccess={handleSuccess}
      />
    </>
  )
}