<?php
/**
 * ambre-tool-sql.php — NL → SQL generator
 */
header('Content-Type: application/json');
if ($_SERVER['REQUEST_METHOD'] !== 'POST') { echo json_encode(['ok'=>false,'error'=>'POST only']); exit; }

$input = json_decode(file_get_contents('php://input'), true);
$query = trim($input['query'] ?? $input['topic'] ?? '');
$dialect = $input['dialect'] ?? 'postgresql';
if (strlen($query) < 3) { echo json_encode(['ok'=>false,'error'=>'query too short']); exit; }
$query = substr($query, 0, 800);

$prompt = "Expert SQL $dialect. Traduis la demande en langue naturelle en SQL:\n\n\"$query\"\n\n"
  . "Retourne UNIQUEMENT un JSON:\n"
  . "{\n"
  . "  \"sql\": \"SELECT ... FROM ... WHERE ...;\",\n"
  . "  \"explanation\": \"Bref explication de ce que fait la requete\",\n"
  . "  \"tables_needed\": [\"table1\",\"table2\"],\n"
  . "  \"dialect\": \"$dialect\",\n"
  . "  \"complexity\": \"simple|medium|complex\",\n"
  . "  \"suggested_indexes\": [\"CREATE INDEX ...\"]\n"
  . "}\n\n"
  . "IMPORTANT:\n"
  . "- SQL valide et optimise\n"
  . "- Utiliser jointures appropriees (INNER/LEFT/RIGHT)\n"
  . "- Mettre ORDER BY si sens\n"
  . "- Preciser LIMIT si pertinent\n"
  . "- Si agrecation, utiliser GROUP BY + HAVING\n"
  . "- Explanation en francais\n"
  . "- JSON UNIQUEMENT, aucun texte avant/apres";

$ch = curl_init('http://127.0.0.1:4000/v1/chat/completions');
curl_setopt_array($ch, [
    CURLOPT_POST => true, CURLOPT_RETURNTRANSFER => true,
    CURLOPT_POSTFIELDS => json_encode([
        'model' => 'auto',
        'messages' => [['role'=>'user', 'content'=>$prompt]],
        'max_tokens' => 2000, 'temperature' => 0.3
    ]),
    CURLOPT_HTTPHEADER => ['Content-Type: application/json'],
    CURLOPT_TIMEOUT => 60,
]);
$resp = curl_exec($ch);
$http = curl_getinfo($ch, CURLINFO_HTTP_CODE);
curl_close($ch);

if ($http !== 200) { echo json_encode(['ok'=>false,'error'=>"LLM HTTP $http"]); exit; }

$data = json_decode($resp, true);
$content_raw = $data['choices'][0]['message']['content'] ?? '';

// Balanced JSON extract
if (preg_match('/```(?:json)?\s*\n?(.*?)\n?```/s', $content_raw, $m)) { $content_raw = $m[1]; }
$jstart = strpos($content_raw, '{');
if ($jstart !== false) {
    $depth = 0; $jend = -1;
    for ($i = $jstart; $i < strlen($content_raw); $i++) {
        if ($content_raw[$i] === '{') $depth++;
        elseif ($content_raw[$i] === '}') { $depth--; if ($depth === 0) { $jend = $i; break; } }
    }
    if ($jend > $jstart) $content_raw = substr($content_raw, $jstart, $jend - $jstart + 1);
}
$result = json_decode($content_raw, true);

if (!$result || !isset($result['sql'])) {
    echo json_encode(['ok'=>false,'error'=>'invalid JSON','raw'=>substr($content_raw,0,300)]); exit;
}

echo json_encode([
    'ok' => true,
    'sql' => $result['sql'],
    'explanation' => $result['explanation'] ?? '',
    'tables_needed' => $result['tables_needed'] ?? [],
    'dialect' => $result['dialect'] ?? $dialect,
    'complexity' => $result['complexity'] ?? 'medium',
    'suggested_indexes' => $result['suggested_indexes'] ?? [],
    'result' => $result['sql'], // for inline kind render
]);