import 'package:cdb_ui/api.dart';
import 'package:cdb_ui/pages/expandable_list.dart';
import 'package:cdb_ui/pages/transaction.dart';
import 'package:flutter/material.dart';

class StatsPage extends StatelessWidget {
  const StatsPage({super.key});

  Future<(List<MinItem>, List<Transaction>, GlobalItemStat)>
      _fetchData() async {
    return (
      await API().getItemsUnderMin(),
      await API().getExpiredItems(),
      await API().getGlobalItemStat()
    );
  }

  @override
  Widget build(BuildContext context) {
    // todo : add global statistics
    // todo : demand stat
    // todo : stat on origin + destination

    // global origin / destinations

    return Scaffold(
      appBar: AppBar(
        title: const Text("Home"),
      ),
      body: FutureBuilder(
        future: _fetchData(),
        builder: (context, snapshot) {
          if (!snapshot.hasData) {
            return const CircularProgressIndicator();
          }

          var data = snapshot.data!;
          var min = data.$1;
          var expired = data.$2;
          var globalStat = data.$3;

          return Column(
            children: [
              Card(
                  margin: const EdgeInsets.all(10.0),
                  child: Padding(
                    padding: const EdgeInsets.all(10.0),
                    child: Row(
                      mainAxisAlignment: MainAxisAlignment.spaceBetween,
                      children: [
                        IconText(Icons.data_object,
                            "Items: ${globalStat.itemCount}"),
                        IconText(Icons.list_alt,
                            "Inventory: ${globalStat.totalTransactions}"),
                        IconText(Icons.money,
                            "Price: ${globalStat.totalPrice.toStringAsFixed(2)} €")
                      ],
                    ),
                  )),

              if (min.isNotEmpty)
                const ListTile(
                    title: Text(
                  "Items under Minimum",
                  style: TextStyle(fontWeight: FontWeight.bold, fontSize: 20),
                )),
              ...min.map((item) {
                var (itemID, variant) = itemVariant(item.itemVariant);
                var name = API().getItem(itemID).variants[variant]!.name;

                return ListTile(
                  title: Text("$name under minimum. Needs ${item.need} more."),
                );
              }).toList(),

              if (expired.isNotEmpty)
                const ListTile(
                    title: Text(
                  "Expired Items",
                  style: TextStyle(fontWeight: FontWeight.bold, fontSize: 20),
                )),

              // Mapping expired list to widgets
              ...expired.map((item) {
                return ListTile(
                  title: TransactionCard(item, () {}),
                );
              }).toList(),
            ],
          );
        },
      ),
    );
  }
}

class ItemStatPage extends StatelessWidget {
  final Item item;

  const ItemStatPage(this.item, {super.key});

  // todo : avg time of transaction active

  ExpandableListItem buildVariantStat(String variant) {
    return ExpandableListItem(
        body: FutureBuilder(
          future: API().getStat(item.id, variant, full: true),
          builder: (context, snapshot) {
            if (!snapshot.hasData) {
              return const CircularProgressIndicator();
            }

            var data = snapshot.data! as FullItemVariantStat;

            return Column(
              children: [
                Text("Amount: ${data.amount}"),
                Text("Total Cost: ${data.totalPrice}"),
                Text("Expiry Rate: ${data.expiryRate}"),
                ...data.origins.keys.map((key) {
                  var originStat = data.origins[key]!;
                  return Column(children: [
                    Text("Inventory: ${originStat.inventory}"),
                    Text(
                        "Average Price: ${originStat.averagePrice.toStringAsFixed(2)} €"),
                  ]);
                }).toList()
              ],
            );
          },
        ),
        header: Text(item.variants[variant]!.name));
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text("Statistics of ${item.name}"),
      ),
      body: Column(children: [
        ExpandableList(item.variants.keys.map(buildVariantStat).toList())
      ]),
    );
  }
}