import { useEffect, useState } from 'react'
import {
  AssetStateBadge,
  Avatar,
  Button,
  EmployeeStatusBadge,
  EmptyState,
  HistoryActionBadge,
  Icon,
  SearchInput,
  Toolbar,
} from '../ui'
import { isDateType, isNumericType, toISODate } from '../../api/recordView'
import { displayLabel, formatDate } from '../../utils/format'
import { FileLinks, imageSources } from './FieldValue'

/**
 * Renders a record view straight from the backend response: the columns are
 * whatever `config.fields` returns, in that order, with the backend's own
 * labels. Paging, sorting and search are handled by the server.
 * `toolbar` adds controls (e.g. a filter) next to the search box. A field with
 * `sortable: false` can't be sorted. A rich column (see api/richColumns.js)
 * shows several fields in one cell and sorts by its `sort_key`.
 */
export default function RecordView({
  fields,
  rows,
  pagination,
  loading,
  error,
  query,
  setPage,
  setSearch,
  setSort,
  rowKey = 'instance_id',
  onRowClick,
  emptyText = 'No records yet.',
  toolbar,
}) {
  const [term, setTerm] = useState(query.search)

  // Debounce typing so we don't fire a request per keystroke.
  useEffect(() => {
    if (term === query.search) return undefined
    const id = setTimeout(() => setSearch(term), 350)
    return () => clearTimeout(id)
  }, [term, query.search, setSearch])

  // A rich column's fields stay searchable.
  const searchable = fields
    .flatMap((f) => (f.data_type === 'rich' ? [...f.title, ...f.subtitle] : [f]))
    .filter((f) => f.is_search)
  const columns = fields.filter((f) => f.field_key !== 'id')

  const sortKey = (field) => field.sort_key ?? field.field_key

  function toggleSort(field) {
    const dir = query.sortBy === sortKey(field) && query.sortDir === 'asc' ? 'desc' : 'asc'
    setSort(sortKey(field), dir)
  }

  const page = pagination?.page ?? 1
  const totalPages = pagination?.total_pages ?? 1
  const total = pagination?.total_count ?? rows.length

  return (
    <>
      <Toolbar count={total} countLabel="records">
        {searchable.length > 0 && (
          <SearchInput
            value={term}
            onChange={setTerm}
            placeholder={`Search by ${searchable.map((f) => displayLabel(f.output_label)).join(', ')}…`}
          />
        )}
        {toolbar}
        {loading && <span className="toolbar__count">Loading…</span>}
      </Toolbar>

      {error && (
        <div className="notice notice--danger" role="alert">
          <Icon name="alert" size={15} />
          <span>{error}</span>
        </div>
      )}

      <div className="table-wrap">
        <table className="table">
          <thead>
            <tr>
              {columns.map((field) => {
                const label = displayLabel(field.output_label || field.field_key)
                if (field.sortable === false) return <th key={field.field_key}>{label}</th>
                const sorted = query.sortBy === sortKey(field)
                return (
                  <th
                    key={field.field_key}
                    className={`is-sortable${sorted ? ' is-sorted' : ''}`}
                    onClick={() => toggleSort(field)}
                  >
                    {label}
                    <span className="table__sort">
                      {sorted ? (query.sortDir === 'asc' ? '▲' : '▼') : '⇅'}
                    </span>
                  </th>
                )
              })}
            </tr>
          </thead>
          <tbody>
            {rows.length === 0 ? (
              <tr className="table__empty">
                <td colSpan={Math.max(columns.length, 1)}>
                  <EmptyState
                    icon={loading ? '⏳' : '📭'}
                    title={loading ? 'Loading records' : 'No records'}
                    text={loading ? 'Fetching from the workflow…' : emptyText}
                  />
                </td>
              </tr>
            ) : (
              rows.map((row, i) => (
                <tr
                  key={row[rowKey] ?? row._pk_value ?? row.id ?? i}
                  className={onRowClick ? 'is-clickable' : undefined}
                  onClick={onRowClick ? () => onRowClick(row) : undefined}
                >
                  {columns.map((field) => (
                    <td key={field.field_key} className={cellClass(field)}>
                      {field.data_type === 'rich'
                        ? renderRichCell(field, row)
                        : renderCell(field, row[field.field_key])}
                    </td>
                  ))}
                </tr>
              ))
            )}
          </tbody>
        </table>
      </div>

      {totalPages > 1 && (
        <div className="pager">
          <Button
            size="sm"
            icon="chevronLeft"
            disabled={page <= 1 || loading}
            onClick={() => setPage(page - 1)}
          >
            Previous
          </Button>
          <span className="pager__label">
            Page {page} of {totalPages}
          </span>
          <Button
            size="sm"
            disabled={page >= totalPages || loading}
            onClick={() => setPage(page + 1)}
          >
            Next
          </Button>
        </div>
      )}
    </>
  )
}

function cellClass(field) {
  if (field.data_type === 'id_gen') return 'cell-mono'
  if (isNumericType(field.data_type)) return 'cell-mono'
  return undefined
}

const present = (v) => v !== null && v !== undefined && v !== ''

/** A rich column: its title fields in bold, its subtitle fields in a line below. */
function renderRichCell(field, row) {
  const title = field.title.filter((p) => present(row[p.field_key]))
  const subtitle = field.subtitle.filter((p) => present(row[p.field_key]))
  if (!title.length && !subtitle.length) return <span className="cell-muted">—</span>

  const join = (parts, sep) =>
    parts.map((p, i) => (
      <span key={p.field_key}>
        {i > 0 && sep}
        {p.prefix && `${p.prefix} `}
        {renderCell(p, row[p.field_key])}
      </span>
    ))
  const name = title.map((p) => String(row[p.field_key])).join(' ')

  return (
    <div className="cell-person">
      {field.avatar && name && <Avatar name={name} />}
      <div>
        {title.length > 0 && <div className="cell-person__name">{join(title, ' ')}</div>}
        {subtitle.length > 0 && <div className="cell-person__sub">{join(subtitle, ' · ')}</div>}
      </div>
    </div>
  )
}

function renderCell(field, value) {
  if (value === null || value === undefined || value === '') {
    return <span className="cell-muted">—</span>
  }

  if (field.data_type === 'image') {
    // Several photos (Front, Back…): show the first and how many more there are.
    const [first, ...more] = imageSources(value)
    if (!first) {
      // Uploaded file objects ({ blob_path, original_name… }) carry no URL to show.
      const count = Array.isArray(value) ? value.length : 0
      return <span className="cell-muted">{count ? `${count} photo${count > 1 ? 's' : ''}` : '—'}</span>
    }
    return (
      <span className="record-thumbs">
        <img className="record-thumb" src={first} alt="" loading="lazy" />
        {more.length > 0 && <span className="cell-muted">+{more.length}</span>}
      </span>
    )
  }
  if (field.data_type === 'file') {
    return <FileLinks value={value} label="View" />
  }
  if (isDateType(field.data_type)) {
    return formatDate(toISODate(value))
  }
  if (field.data_type === 'email') {
    return <span className="cell-muted">{String(value)}</span>
  }
  if (field.data_type === 'id_gen') {
    return <span className="cell-primary">{String(value)}</span>
  }
  if (field.data_type === 'employee_status') {
    return <EmployeeStatusBadge status={String(value)} />
  }
  if (field.data_type === 'asset_state') {
    return <AssetStateBadge state={String(value)} />
  }
  if (field.data_type === 'history_action') {
    return <HistoryActionBadge action={String(value)} />
  }
  if (typeof value === 'object') {
    return <span className="cell-muted">{JSON.stringify(value)}</span>
  }
  return String(value)
}