'use client'

import { useCallback, useEffect, useState } from 'react'
import { Badge } from '@/components/ui/badge'
import { Button } from '@/components/ui/button'
import { Panel, PanelContent, PanelHeader, PanelTitle } from '@/components/ui/panel'

// #38 — direct DB CRUD for the admin. ponytail: deliberately unauthenticated (explicit request);
// add auth before this is reachable beyond the dev host.
interface AdminColumnInfo { name: string; type: string; pk: number }
interface AdminTableInfo { name: string; columns: AdminColumnInfo[]; count: number }
interface AdminRows { rows: Record<string, unknown>[]; total: number }

// Form state is all strings (one input per column); parsed on save against the column type.
function parseValue(raw: string, col: AdminColumnInfo): number | string | null {
  const v = raw.trim()
  if (v === '' || v.toLowerCase() === 'null') return null
  if (/INT|REAL|FLOA|DOUB/.test(col.type)) {
    const n = Number(v)
    if (!Number.isFinite(n)) throw new Error(`'${col.name}' must be a number, got '${v}'`)
    return col.type.includes('INT') ? Math.trunc(n) : n
  }
  return v
}

function cellText(value: unknown): string {
  return value === null || value === undefined ? '—' : String(value)
}

export function AdminPanel({ onClose }: { onClose: () => void }) {
  const [tables, setTables] = useState<AdminTableInfo[] | null>(null)
  const [selected, setSelected] = useState<string | null>(null)
  const [rows, setRows] = useState<AdminRows | null>(null)
  // null = form closed; { key: null } = add row; { key: {...} } = edit that row.
  const [editing, setEditing] = useState<{ key: Record<string, number> | null } | null>(null)
  const [form, setForm] = useState<Record<string, string>>({})
  const [error, setError] = useState<string | null>(null)

  const table = tables?.find((t) => t.name === selected) ?? null

  const refreshTables = useCallback(async () => {
    try {
      const res = await fetch('/api/admin/tables')
      if (!res.ok) throw new Error(`HTTP ${res.status}`)
      setTables((await res.json()) as AdminTableInfo[])
    } catch (err) {
      setError(err instanceof Error ? err.message : String(err))
    }
  }, [])

  const refreshRows = useCallback(async (name: string) => {
    try {
      const res = await fetch(`/api/admin/tables/${encodeURIComponent(name)}/rows`)
      if (!res.ok) throw new Error(`HTTP ${res.status}`)
      setRows((await res.json()) as AdminRows)
    } catch (err) {
      setError(err instanceof Error ? err.message : String(err))
    }
  }, [])

  useEffect(() => {
    void refreshTables()
  }, [refreshTables])

  useEffect(() => {
    if (!selected) return
    setRows(null)
    void refreshRows(selected)
  }, [selected, refreshRows])

  const pkColumns = (t: AdminTableInfo): AdminColumnInfo[] => t.columns.filter((c) => c.pk > 0).sort((a, b) => a.pk - b.pk)

  const rowKey = (t: AdminTableInfo, row: Record<string, unknown>): Record<string, number> =>
    Object.fromEntries(pkColumns(t).map((c) => [c.name, Number(row[c.name])]))

  const openAdd = () => {
    if (!table) return
    setEditing({ key: null })
    setForm(Object.fromEntries(table.columns.map((c) => [c.name, ''])))
    setError(null)
  }

  const openEdit = (row: Record<string, unknown>) => {
    if (!table) return
    setEditing({ key: rowKey(table, row) })
    setForm(Object.fromEntries(table.columns.map((c) => [c.name, row[c.name] == null ? '' : String(row[c.name])])))
    setError(null)
  }

  const save = async () => {
    if (!table || !editing) return
    try {
      const payload: Record<string, number | string | null> = {}
      for (const col of table.columns) payload[col.name] = parseValue(form[col.name] ?? '', col)
      const url = `/api/admin/tables/${encodeURIComponent(table.name)}/rows`
      const res = await fetch(url, {
        method: editing.key === null ? 'POST' : 'PATCH',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify(editing.key === null ? payload : { key: editing.key, values: payload }),
      })
      const body = (await res.json()) as { error?: string } & Record<string, unknown>
      if (!res.ok) throw new Error(body.error ?? `HTTP ${res.status}`)
      setEditing(null)
      setError(null)
      await Promise.all([refreshRows(table.name), refreshTables()])
    } catch (err) {
      setError(err instanceof Error ? err.message : String(err))
    }
  }

  const remove = async (row: Record<string, unknown>) => {
    if (!table) return
    try {
      const res = await fetch(`/api/admin/tables/${encodeURIComponent(table.name)}/rows`, {
        method: 'DELETE',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify({ key: rowKey(table, row) }),
      })
      const body = (await res.json()) as { error?: string }
      if (!res.ok) throw new Error(body.error ?? `HTTP ${res.status}`)
      await Promise.all([refreshRows(table.name), refreshTables()])
    } catch (err) {
      setError(err instanceof Error ? err.message : String(err))
    }
  }

  const inputStyle: React.CSSProperties = {
    width: '100%',
    background: 'var(--background)',
    border: '1px solid var(--border)',
    color: 'var(--text-secondary)',
    fontFamily: 'inherit',
    fontSize: '0.68rem',
    padding: '0.3rem 0.4rem',
    outline: 'none',
  }

  return (
    <div
      style={{
        position: 'fixed',
        inset: 0,
        zIndex: 100,
        background: 'rgba(0, 0, 0, 0.75)',
        display: 'flex',
        alignItems: 'center',
        justifyContent: 'center',
        padding: '1rem',
      }}
    >
      <Panel notch="md" style={{ width: 'min(980px, 100%)', height: 'min(640px, 100%)', display: 'flex', flexDirection: 'column' }}>
        <PanelHeader>
          <PanelTitle>ADMIN // DB CRUD</PanelTitle>
          <Badge variant="WARNING">NO AUTH</Badge>
          <div style={{ marginLeft: 'auto' }}>
            <Button size="SM" onClick={onClose}>CLOSE</Button>
          </div>
        </PanelHeader>

        <div style={{ flex: 1, display: 'grid', gridTemplateColumns: '200px 1fr', gap: '1px', background: 'var(--border)', minHeight: 0 }}>
          {/* ── TABLE LIST ── */}
          <div style={{ background: 'var(--surface)', overflowY: 'auto', padding: '0.5rem' }}>
            {!tables ? (
              <span style={{ fontSize: '0.62rem', color: 'var(--text-muted)', letterSpacing: '0.12em' }}>LOADING…</span>
            ) : (
              tables.map((t) => (
                <button
                  key={t.name}
                  onClick={() => setSelected(t.name)}
                  style={{
                    display: 'flex',
                    justifyContent: 'space-between',
                    alignItems: 'center',
                    width: '100%',
                    gap: '0.5rem',
                    padding: '0.4rem 0.5rem',
                    marginBottom: '2px',
                    background: selected === t.name ? 'var(--surface-raised)' : 'transparent',
                    border: `1px solid ${selected === t.name ? 'var(--color-green)' : 'var(--border)'}`,
                    color: selected === t.name ? 'var(--color-green)' : 'var(--text-secondary)',
                    fontFamily: 'inherit',
                    fontSize: '0.68rem',
                    letterSpacing: '0.06em',
                    cursor: 'pointer',
                  }}
                >
                  <span>{t.name}</span>
                  <span style={{ color: 'var(--text-muted)' }}>{t.count}</span>
                </button>
              ))
            )}
          </div>

          {/* ── ROWS / EDITOR ── */}
          <div style={{ background: 'var(--surface)', display: 'flex', flexDirection: 'column', minHeight: 0 }}>
            {!table ? (
              <PanelContent>
                <span style={{ fontSize: '0.62rem', color: 'var(--text-muted)', letterSpacing: '0.12em' }}>SELECT A TABLE</span>
              </PanelContent>
            ) : (
              <>
                <div
                  style={{
                    display: 'flex',
                    alignItems: 'center',
                    gap: '0.5rem',
                    padding: '0.4rem 0.75rem',
                    borderBottom: '1px solid var(--border)',
                  }}
                >
                  <span style={{ fontSize: '0.68rem', color: 'var(--color-green)', letterSpacing: '0.1em' }}>{table.name}</span>
                  {rows && (
                    <Badge variant="ACTIVE">
                      {rows.rows.length} / {rows.total}
                    </Badge>
                  )}
                  <div style={{ marginLeft: 'auto', display: 'flex', gap: '0.4rem' }}>
                    {!editing && <Button size="SM" variant="EXEC" onClick={openAdd}>ADD ROW</Button>}
                    {error && (
                      <span style={{ fontSize: '0.62rem', color: 'var(--color-red)', alignSelf: 'center' }}>{error}</span>
                    )}
                  </div>
                </div>

                {editing && (
                  <div style={{ padding: '0.5rem 0.75rem', borderBottom: '1px solid var(--border)' }}>
                    <div style={{ display: 'grid', gridTemplateColumns: 'repeat(auto-fill, minmax(160px, 1fr))', gap: '0.4rem' }}>
                      {table.columns.map((c) => (
                        <label key={c.name} style={{ display: 'flex', flexDirection: 'column', gap: '0.2rem' }}>
                          <span style={{ fontSize: '0.58rem', color: 'var(--text-muted)', letterSpacing: '0.1em' }}>
                            {c.name.toUpperCase()}
                            {c.pk > 0 ? ` (PK${c.pk})` : ''} · {c.type}
                          </span>
                          <input
                            style={inputStyle}
                            value={form[c.name] ?? ''}
                            onChange={(e) => setForm((f) => ({ ...f, [c.name]: e.target.value }))}
                          />
                        </label>
                      ))}
                    </div>
                    <div style={{ display: 'flex', gap: '0.4rem', marginTop: '0.5rem' }}>
                      <Button size="SM" variant="EXEC" onClick={() => void save()}>SAVE</Button>
                      <Button size="SM" onClick={() => setEditing(null)}>CANCEL</Button>
                    </div>
                  </div>
                )}

                <div style={{ flex: 1, overflowY: 'auto' }}>
                  {!rows ? (
                    <PanelContent>
                      <span style={{ fontSize: '0.62rem', color: 'var(--text-muted)', letterSpacing: '0.12em' }}>LOADING…</span>
                    </PanelContent>
                  ) : rows.rows.length === 0 ? (
                    <PanelContent>
                      <span style={{ fontSize: '0.62rem', color: 'var(--text-muted)', letterSpacing: '0.08em' }}>EMPTY TABLE</span>
                    </PanelContent>
                  ) : (
                    <table style={{ width: '100%', borderCollapse: 'collapse', fontSize: '0.65rem' }}>
                      <thead>
                        <tr>
                          {table.columns.map((c) => (
                            <th
                              key={c.name}
                              style={{
                                position: 'sticky',
                                top: 0,
                                background: 'var(--surface-raised)',
                                color: 'var(--text-muted)',
                                textAlign: 'left',
                                padding: '0.35rem 0.5rem',
                                borderBottom: '1px solid var(--border)',
                                letterSpacing: '0.08em',
                                whiteSpace: 'nowrap',
                              }}
                            >
                              {c.name}
                              {c.pk > 0 ? ` (PK${c.pk})` : ''}
                            </th>
                          ))}
                          <th style={{ position: 'sticky', top: 0, background: 'var(--surface-raised)', padding: '0.35rem 0.5rem', borderBottom: '1px solid var(--border)' }} />
                        </tr>
                      </thead>
                      <tbody>
                        {rows.rows.map((row) => (
                          <tr key={JSON.stringify(rowKey(table, row))}>
                            {table.columns.map((c) => (
                              <td
                                key={c.name}
                                style={{
                                  padding: '0.3rem 0.5rem',
                                  borderBottom: '1px solid var(--border)',
                                  color: row[c.name] === null ? 'var(--text-muted)' : 'var(--text-secondary)',
                                  whiteSpace: 'nowrap',
                                  overflow: 'hidden',
                                  textOverflow: 'ellipsis',
                                  maxWidth: '220px',
                                }}
                              >
                                {cellText(row[c.name])}
                              </td>
                            ))}
                            <td style={{ padding: '0.3rem 0.5rem', borderBottom: '1px solid var(--border)', whiteSpace: 'nowrap' }}>
                              <span style={{ display: 'inline-flex', gap: '0.3rem' }}>
                                <Button size="SM" onClick={() => openEdit(row)}>EDIT</Button>
                                <Button size="SM" variant="ABORT" onClick={() => void remove(row)}>DEL</Button>
                              </span>
                            </td>
                          </tr>
                        ))}
                      </tbody>
                    </table>
                  )}
                </div>
              </>
            )}
          </div>
        </div>
      </Panel>
    </div>
  )
}