import '../models/habit.dart';
import 'frame_candidate.dart';

/// Parses function-calling JSON into FrameCandidate list. Throws
/// [FormatException] on missing/invalid top-level shape; silently skips
/// individual malformed items.
List<FrameCandidate> parseFrameCandidates(Map<String, dynamic> json) {
  final raw = json['candidates'];
  if (raw == null) {
    throw const FormatException('candidates missing');
  }
  if (raw is! List) {
    throw const FormatException('candidates not array');
  }

  final result = <FrameCandidate>[];
  for (final item in raw) {
    if (item is! Map) continue;
    final map = item.map((k, v) => MapEntry(k.toString(), v));

    final levelStr = map['level'];
    if (levelStr is! String) continue;
    final level = _parseLevel(levelStr);
    if (level == null) continue;

    final framedText = map['framed_text'];
    if (framedText is! String) continue;
    final trimmed = framedText.trim();
    if (trimmed.isEmpty || trimmed.length > 120) continue;

    double confidence = 0.5;
    final c = map['confidence'];
    if (c is num) {
      confidence = c.toDouble().clamp(0.0, 1.0);
    }

    final src = map['source_pattern_id'];
    result.add(FrameCandidate(
      level: level,
      framedText: trimmed,
      confidence: confidence,
      sourcePatternId: src is String ? src : null,
    ));
  }
  return result;
}

FrameLevel? _parseLevel(String s) {
  switch (s.toUpperCase()) {
    case 'L0':
      return FrameLevel.l0;
    case 'L1':
      return FrameLevel.l1;
    case 'L2':
      return FrameLevel.l2;
    case 'L3':
      return FrameLevel.l3;
  }
  return null;
}