import 'package:flutter/material.dart';
import 'package:manager_app/constants.dart';
import 'package:manager_app/l10n/app_localizations.dart';

/// Forme des données attendue par l'onglet « Ce que demandent vos visiteurs ».
///
/// Écrite avant le backend, volontairement : c'est l'affichage qui décide de ce que
/// le job de regroupement doit produire, pas l'inverse. L'endpoint à écrire côté
/// manager-service doit rendre exactement cette structure, alimentée par la table
/// `VisitorQuestion` (déjà en base) et son job de regroupement en thèmes.
class GuideIaInsights {
  final int questions;
  final int unanswered;
  final int themes;
  final int languages;
  final List<CountedLabel> unansweredQuestions;
  final List<CountedLabel> topics;
  final List<CountedLabel> questionLanguages;
  final List<CountedLabel> citedContents;

  const GuideIaInsights({
    required this.questions,
    required this.unanswered,
    required this.themes,
    required this.languages,
    required this.unansweredQuestions,
    required this.topics,
    required this.questionLanguages,
    required this.citedContents,
  });

  factory GuideIaInsights.fromJson(Map<String, dynamic> json) => GuideIaInsights(
        questions: (json['questions'] as num?)?.toInt() ?? 0,
        unanswered: (json['unanswered'] as num?)?.toInt() ?? 0,
        themes: (json['themes'] as num?)?.toInt() ?? 0,
        languages: (json['languages'] as num?)?.toInt() ?? 0,
        unansweredQuestions: CountedLabel.listFrom(json['unansweredQuestions']),
        topics: CountedLabel.listFrom(json['topics']),
        questionLanguages: CountedLabel.listFrom(json['questionLanguages']),
        citedContents: CountedLabel.listFrom(json['citedContents']),
      );
}

class CountedLabel {
  final String label;
  final int count;

  const CountedLabel(this.label, this.count);

  static List<CountedLabel> listFrom(dynamic raw) => (raw as List?)
          ?.map((e) => CountedLabel(
                (e['label'] ?? '').toString(),
                (e['count'] as num?)?.toInt() ?? 0,
              ))
          .toList() ??
      const [];
}

class VisitorQuestionsTab extends StatelessWidget {
  final GuideIaInsights? insights;

  const VisitorQuestionsTab({super.key, required this.insights});

  @override
  Widget build(BuildContext context) {
    final l = AppLocalizations.of(context)!;
    final data = insights;
    if (data == null || data.questions == 0) return _empty(l);

    final wide = MediaQuery.of(context).size.width > 1100;

    // Une carte sans données n'est pas une carte vide à afficher : `topics` reste vide
    // tant que le job de regroupement en thèmes n'a pas tourné, et un cadre avec un titre
    // et rien dedans se lit comme une panne.
    final columns = [
      if (data.topics.isNotEmpty)
        _barsCard(l.guideIaTopicsTitle, l.guideIaInsightsSubCount, data.topics),
      if (data.questionLanguages.isNotEmpty)
        _barsCard(l.guideIaQuestionLanguagesTitle, l.guideIaInsightsSubCount, data.questionLanguages),
      if (data.citedContents.isNotEmpty)
        _barsCard(l.guideIaCitedTitle, l.guideIaCitedSub, data.citedContents),
    ];

    return SingleChildScrollView(
      child: Column(
        crossAxisAlignment: CrossAxisAlignment.start,
        children: [
          _tiles(l, data),
          const SizedBox(height: kSpace6),
          if (data.unansweredQuestions.isNotEmpty) ...[
            _gapCard(l, data),
            const SizedBox(height: kSpace6),
          ],
          if (wide)
            Row(
              crossAxisAlignment: CrossAxisAlignment.start,
              children: [
                for (final card in columns) ...[
                  Expanded(child: card),
                  if (card != columns.last) const SizedBox(width: kSpace6),
                ],
              ],
            )
          else
            for (final card in columns) ...[
              card,
              const SizedBox(height: kSpace6),
            ],
          const SizedBox(height: kSpace6),
          _privacyNote(l),
        ],
      ),
    );
  }

  Widget _empty(AppLocalizations l) {
    return Center(
      child: Padding(
        padding: const EdgeInsets.symmetric(vertical: 64, horizontal: kSpace7),
        child: Column(
          mainAxisSize: MainAxisSize.min,
          children: [
            Icon(Icons.forum_outlined, size: 40, color: kInk3),
            const SizedBox(height: kSpace4),
            Text(l.guideIaInsightsEmpty, style: kTitleCard, textAlign: TextAlign.center),
            const SizedBox(height: kSpace2),
            SizedBox(
              width: 460,
              child: Text(l.guideIaInsightsEmptyHint, style: kSubtitleCard, textAlign: TextAlign.center),
            ),
          ],
        ),
      ),
    );
  }

  Widget _tiles(AppLocalizations l, GuideIaInsights data) {
    final tiles = [
      _Tile(l.guideIaKpiQuestions, data.questions.toString(), false),
      _Tile(l.guideIaKpiUnanswered, data.unanswered.toString(), true),
      _Tile(l.guideIaKpiThemes, data.themes.toString(), false),
      _Tile(l.guideIaKpiLanguages, data.languages.toString(), false),
    ];

    return Container(
      decoration: BoxDecoration(
        border: Border.all(color: kLine),
        borderRadius: BorderRadius.circular(kRadiusCard),
        color: kSurface,
      ),
      child: Row(
        children: [
          for (final tile in tiles)
            Expanded(
              child: Container(
                padding: const EdgeInsets.fromLTRB(16, 14, 16, 15),
                decoration: BoxDecoration(
                  border: tile == tiles.first ? null : Border(left: BorderSide(color: kLine)),
                ),
                child: Column(
                  crossAxisAlignment: CrossAxisAlignment.start,
                  children: [
                    Text(tile.value,
                        style: kMetricMedium.copyWith(color: tile.warn ? kWarning : kInk)),
                    const SizedBox(height: kSpace1),
                    Text(tile.label.toUpperCase(), style: kOverline),
                  ],
                ),
              ),
            ),
        ],
      ),
    );
  }

  /// Bordure ambre : c'est le seul bloc de l'écran qui appelle une action du client.
  /// L'ambre n'est jamais réutilisé comme couleur de série dans les graphes.
  Widget _gapCard(AppLocalizations l, GuideIaInsights data) {
    return _shell(
      borderColor: kWarning,
      child: Column(
        crossAxisAlignment: CrossAxisAlignment.start,
        children: [
          Row(
            children: [
              Container(
                width: 8,
                height: 8,
                decoration: const BoxDecoration(color: kWarning, shape: BoxShape.circle),
              ),
              const SizedBox(width: kSpace3),
              Expanded(child: Text(l.guideIaGapTitle, style: kTitleCard)),
            ],
          ),
          const SizedBox(height: kSpace1),
          Text(l.guideIaGapSub(data.unanswered), style: kSubtitleCard),
          const SizedBox(height: kSpace4),
          for (final q in data.unansweredQuestions)
            Container(
              padding: const EdgeInsets.symmetric(vertical: 9),
              decoration: BoxDecoration(
                border: q == data.unansweredQuestions.first
                    ? null
                    : Border(top: BorderSide(color: kLineSoft)),
              ),
              child: Row(
                crossAxisAlignment: CrossAxisAlignment.start,
                children: [
                  Expanded(child: Text(q.label, style: kTextBody)),
                  const SizedBox(width: kSpace4),
                  Text('${q.count} ×',
                      style: kTextSmall.copyWith(
                          fontFamily: kMonoFamily, color: kWarning)),
                ],
              ),
            ),
        ],
      ),
    );
  }

  /// Une seule mesure par carte, donc une seule teinte : c'est la longueur qui
  /// porte l'information. Colorer chaque barre suggérerait une distinction qui n'existe pas.
  Widget _barsCard(String title, String subtitle, List<CountedLabel> rows) {
    final max = rows.isEmpty ? 1 : rows.map((r) => r.count).reduce((a, b) => a > b ? a : b);

    return _shell(
      child: Column(
        crossAxisAlignment: CrossAxisAlignment.start,
        children: [
          Text(title, style: kTitleCard),
          const SizedBox(height: kSpace1),
          Text(subtitle, style: kSubtitleCard),
          const SizedBox(height: kSpace5),
          for (final row in rows)
            Padding(
              padding: const EdgeInsets.only(bottom: 9),
              child: Row(
                children: [
                  SizedBox(
                    width: 132,
                    child: Text(row.label, style: kTextSmall, overflow: TextOverflow.ellipsis),
                  ),
                  const SizedBox(width: 11),
                  Expanded(
                    child: ClipRRect(
                      borderRadius: BorderRadius.circular(kRadiusTrack),
                      child: LinearProgressIndicator(
                        value: max == 0 ? 0 : row.count / max,
                        minHeight: 9,
                        backgroundColor: kSurface3,
                        color: kBrand,
                      ),
                    ),
                  ),
                  const SizedBox(width: 11),
                  SizedBox(
                    width: 46,
                    child: Text(row.count.toString(),
                        textAlign: TextAlign.right,
                        style: kTextSmall.copyWith(fontFamily: kMonoFamily)),
                  ),
                ],
              ),
            ),
        ],
      ),
    );
  }

  Widget _privacyNote(AppLocalizations l) {
    return Container(
      padding: const EdgeInsets.symmetric(horizontal: 12, vertical: 10),
      decoration: BoxDecoration(
        color: kSurface2,
        border: Border.all(color: kLineSoft),
        borderRadius: BorderRadius.circular(kRadiusInput),
      ),
      child: Row(
        crossAxisAlignment: CrossAxisAlignment.start,
        children: [
          const Icon(Icons.info_outline, size: 16, color: kBrand),
          const SizedBox(width: 9),
          Expanded(child: Text(l.guideIaInsightsPrivacy, style: kSubtitleCard.copyWith(color: kInk2))),
        ],
      ),
    );
  }

  Widget _shell({required Widget child, Color? borderColor}) {
    return Container(
      padding: kCardPadding,
      decoration: BoxDecoration(
        color: kSurface,
        border: Border.all(color: borderColor ?? kLine),
        borderRadius: BorderRadius.circular(kRadiusCard),
      ),
      child: child,
    );
  }
}

class _Tile {
  final String label;
  final String value;
  final bool warn;

  const _Tile(this.label, this.value, this.warn);
}