import "package:flutter/material.dart";
import "package:google_fonts/google_fonts.dart";
import "../demo_identity.dart";
import "../theme/ensup_colors.dart";
import "../models/emprunt_item.dart";
import "../services/emprunt_service.dart";
import "../services/materiel_service.dart";
import "../widgets/ensup_top_bar.dart";
import "../widgets/brand_corners.dart";
import "../widgets/app_message.dart";
import "checklist_retour_screen.dart";

/// Sélection de l'emprunt en cours à restituer (RG15 : ses propres emprunts).
class RestitutionSelectScreen extends StatefulWidget {
  const RestitutionSelectScreen({super.key});

  @override
  State<RestitutionSelectScreen> createState() =>
      _RestitutionSelectScreenState();
}

class _RestitutionSelectScreenState extends State<RestitutionSelectScreen> {
  late Future<List<EmpruntItem>> _future;
  int? _chargementId;

  @override
  void initState() {
    super.initState();
    _future = EmpruntService.getMesEmprunts();
  }

  void _recharger() {
    setState(() => _future = EmpruntService.getMesEmprunts());
  }

  Future<void> _restituer(EmpruntItem emprunt) async {
    setState(() => _chargementId = emprunt.id);
    try {
      final detail = await MaterielService.getDetail(emprunt.materiel.id);
      if (!mounted) {
        return;
      }
      Navigator.of(context).push(
        MaterialPageRoute(
          builder: (_) => ChecklistRetourScreen(
            emprunt: emprunt.copyWith(materiel: detail),
          ),
        ),
      );
    } catch (error) {
      if (!mounted) {
        return;
      }
      AppMessage.erreur(context, error);
    } finally {
      if (mounted) {
        setState(() => _chargementId = null);
      }
    }
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      backgroundColor: EnsupColors.soft,
      body: Stack(
        children: [
          Center(
            child: ConstrainedBox(
              constraints: const BoxConstraints(maxWidth: 1280, maxHeight: 820),
              child: Container(
                margin: const EdgeInsets.all(24),
                decoration: BoxDecoration(
                  color: Colors.white,
                  borderRadius: BorderRadius.circular(16),
                  boxShadow: [
                    BoxShadow(
                      color: EnsupColors.text.withValues(alpha: 0.14),
                      blurRadius: 60,
                      offset: const Offset(0, 18),
                    ),
                  ],
                ),
                clipBehavior: Clip.antiAlias,
                child: Column(
                  children: [
                    EnsupTopBar(
                      brandText: "Restitution",
                      campusTag: DemoIdentity.campusTag,
                      userName: DemoIdentity.userName,
                      userInitials: DemoIdentity.userInitials,
                      onBack: () => Navigator.of(context).pop(),
                    ),
                    Expanded(
                      child: Padding(
                        padding: const EdgeInsets.symmetric(
                          horizontal: 32,
                          vertical: 28,
                        ),
                        child: FutureBuilder<List<EmpruntItem>>(
                          future: _future,
                          builder: (context, snapshot) {
                            if (snapshot.connectionState ==
                                ConnectionState.waiting) {
                              return const Center(
                                child: CircularProgressIndicator(),
                              );
                            }
                            if (snapshot.hasError) {
                              return _ErreurState(
                                message: snapshot.error.toString(),
                                onRetry: _recharger,
                              );
                            }

                            return _contenu(snapshot.data ?? const []);
                          },
                        ),
                      ),
                    ),
                  ],
                ),
              ),
            ),
          ),
          const Positioned.fill(child: BrandCorners()),
        ],
      ),
    );
  }

  Widget _contenu(List<EmpruntItem> emprunts) {
    return Column(
      crossAxisAlignment: CrossAxisAlignment.start,
      children: [
        Text(
          "Sélectionner le matériel à restituer",
          style: GoogleFonts.darkerGrotesque(
            fontSize: 28,
            height: 1,
            fontWeight: FontWeight.w900,
            color: EnsupColors.text,
          ),
        ),
        const SizedBox(height: 6),
        Text(
          "${emprunts.length} emprunt${emprunts.length > 1 ? "s" : ""} en cours associé${emprunts.length > 1 ? "s" : ""} à votre compte.",
          style: GoogleFonts.titilliumWeb(
            fontSize: 13,
            color: EnsupColors.muted,
          ),
        ),
        const SizedBox(height: 18),
        Expanded(
          child: emprunts.isEmpty
              ? const _EmptyState()
              : ListView.separated(
                  itemCount: emprunts.length,
                  separatorBuilder: (_, _) => const SizedBox(height: 10),
                  itemBuilder: (context, index) {
                    final emprunt = emprunts[index];
                    return _EmpruntCard(
                      emprunt: emprunt,
                      loading: _chargementId == emprunt.id,
                      onRestituer: () => _restituer(emprunt),
                    );
                  },
                ),
        ),
      ],
    );
  }
}

class _EmpruntCard extends StatelessWidget {
  const _EmpruntCard({
    required this.emprunt,
    required this.loading,
    required this.onRestituer,
  });

  final EmpruntItem emprunt;
  final bool loading;
  final VoidCallback onRestituer;

  @override
  Widget build(BuildContext context) {
    return Container(
      padding: const EdgeInsets.symmetric(horizontal: 18, vertical: 16),
      decoration: BoxDecoration(
        color: Colors.white,
        borderRadius: BorderRadius.circular(12),
        border: Border.all(color: EnsupColors.line, width: 1.5),
        boxShadow: [
          BoxShadow(
            color: EnsupColors.text.withValues(alpha: 0.035),
            blurRadius: 10,
            offset: const Offset(0, 3),
          ),
        ],
      ),
      child: LayoutBuilder(
        builder: (context, constraints) {
          final compact = constraints.maxWidth < 650;
          final information = Row(
            children: [
              Container(
                width: 46,
                height: 46,
                decoration: BoxDecoration(
                  color: EnsupColors.teal.withValues(alpha: 0.09),
                  borderRadius: BorderRadius.circular(10),
                ),
                child: Icon(
                  emprunt.materiel.icon,
                  color: EnsupColors.teal,
                  size: 21,
                ),
              ),
              const SizedBox(width: 14),
              Expanded(
                child: Column(
                  crossAxisAlignment: CrossAxisAlignment.start,
                  children: [
                    Text(
                      emprunt.materiel.nom,
                      maxLines: 2,
                      overflow: TextOverflow.ellipsis,
                      style: GoogleFonts.darkerGrotesque(
                        fontWeight: FontWeight.w800,
                        fontSize: 17,
                        height: 1.05,
                        color: EnsupColors.text,
                      ),
                    ),
                    const SizedBox(height: 4),
                    Text(
                      "Emprunté le ${emprunt.dateEmprunt} · Retour prévu ${emprunt.retourPrevu}",
                      maxLines: 2,
                      overflow: TextOverflow.ellipsis,
                      style: GoogleFonts.titilliumWeb(
                        fontSize: 12,
                        color: EnsupColors.muted,
                      ),
                    ),
                  ],
                ),
              ),
            ],
          );
          final actions = Wrap(
            spacing: 10,
            runSpacing: 8,
            crossAxisAlignment: WrapCrossAlignment.center,
            alignment: WrapAlignment.end,
            children: [
              Container(
                padding: const EdgeInsets.symmetric(
                  horizontal: 11,
                  vertical: 5,
                ),
                decoration: BoxDecoration(
                  color: emprunt.statut == "EN_RETARD"
                      ? EnsupColors.red.withValues(alpha: 0.09)
                      : const Color(0xFFFEF9C3),
                  borderRadius: BorderRadius.circular(999),
                ),
                child: Text(
                  emprunt.statut == "EN_RETARD" ? "En retard" : "En cours",
                  style: GoogleFonts.darkerGrotesque(
                    fontSize: 13,
                    fontWeight: FontWeight.w700,
                    color: emprunt.statut == "EN_RETARD"
                        ? EnsupColors.red
                        : const Color(0xFFA16207),
                  ),
                ),
              ),
              FilledButton.icon(
                onPressed: loading ? null : onRestituer,
                style: FilledButton.styleFrom(
                  backgroundColor: EnsupColors.cyan,
                  padding: const EdgeInsets.symmetric(
                    horizontal: 15,
                    vertical: 11,
                  ),
                  shape: RoundedRectangleBorder(
                    borderRadius: BorderRadius.circular(9),
                  ),
                ),
                icon: loading
                    ? const SizedBox(
                        width: 15,
                        height: 15,
                        child: CircularProgressIndicator(
                          strokeWidth: 2,
                          color: Colors.white,
                        ),
                      )
                    : const Icon(Icons.assignment_return_outlined, size: 16),
                label: Text(
                  loading ? "Chargement" : "Restituer",
                  style: GoogleFonts.darkerGrotesque(
                    fontWeight: FontWeight.w700,
                    fontSize: 14,
                  ),
                ),
              ),
            ],
          );

          if (compact) {
            return Column(
              crossAxisAlignment: CrossAxisAlignment.stretch,
              children: [
                information,
                const SizedBox(height: 14),
                Align(alignment: Alignment.centerRight, child: actions),
              ],
            );
          }

          return Row(
            children: [
              Expanded(child: information),
              const SizedBox(width: 16),
              actions,
            ],
          );
        },
      ),
    );
  }
}

class _EmptyState extends StatelessWidget {
  const _EmptyState();

  @override
  Widget build(BuildContext context) {
    return Center(
      child: Text(
        "Aucun emprunt en cours à restituer",
        style: GoogleFonts.titilliumWeb(fontSize: 14, color: EnsupColors.muted),
      ),
    );
  }
}

class _ErreurState extends StatelessWidget {
  const _ErreurState({required this.message, required this.onRetry});

  final String message;
  final VoidCallback onRetry;

  @override
  Widget build(BuildContext context) {
    return Center(
      child: Column(
        mainAxisSize: MainAxisSize.min,
        children: [
          const Icon(
            Icons.cloud_off_outlined,
            size: 40,
            color: EnsupColors.muted,
          ),
          const SizedBox(height: 12),
          Text(
            message,
            textAlign: TextAlign.center,
            style: GoogleFonts.titilliumWeb(
              fontSize: 14,
              color: EnsupColors.text2,
            ),
          ),
          const SizedBox(height: 14),
          OutlinedButton(
            onPressed: onRetry,
            child: Text(
              "Réessayer",
              style: GoogleFonts.darkerGrotesque(fontWeight: FontWeight.w700),
            ),
          ),
        ],
      ),
    );
  }
}