import 'package:cdb_ui/api.dart' as API;
import 'package:cdb_ui/pages/flow/active_flow_page.dart';
import 'package:cdb_ui/pages/transaction.dart';
import 'package:flutter/material.dart';

class CreateFlowPage extends StatefulWidget {
  final API.FlowInfo info;
  final Function refresh;
  final API.Flow? previousFlow;

  const CreateFlowPage(this.info, this.refresh, {this.previousFlow, super.key});

  @override
  State<CreateFlowPage> createState() => _CreateFlowPageState();
}

class _CreateFlowPageState extends State<CreateFlowPage> {
  List<API.Transaction> depends = [];

  void _create(BuildContext context) {
    if (widget.previousFlow != null) {
      API
          .API()
          .continueFlow(widget.previousFlow!.id,
              input: depends.map((x) => x.uuid).toList())
          .then((x) {
        API.API().getFlow(x).then((flow) {
          var info = API.API().getFlowInfo(flow.kind);
          Navigator.of(context).pushReplacement(MaterialPageRoute(
            builder: (context) => ActiveFlowPage(flow, info),
          ));
        });
      });
      return;
    }

    API
        .API()
        .startFlow(widget.info.id, input: depends.map((x) => x.uuid).toList())
        .then((flowID) {
      widget.refresh();
      API.API().getFlow(flowID).then((flow) {
        Navigator.of(context).pushReplacement(MaterialPageRoute(
            builder: (context) => ActiveFlowPage(flow, widget.info)));
      });
    });
  }

  void selectDependItems(BuildContext context, String itemVariant) {
    var (item, variant) = API.itemVariant(itemVariant);

    API.API().getInventoryOfVariant(item, variant).then((transactions) {
      Navigator.of(context).push(MaterialPageRoute(
        builder: (context) {
          return TransactionSelectPage(transactions, onSelect: (t) {
            if (!depends.contains(t)) {
              setState(() {
                depends.add(t);
              });
            }
          }, exclude: depends);
        },
      ));
    });
  }

  List<Widget> buildInputSelection(BuildContext context) {
    if (widget.info.depends.isEmpty) {
      return [];
    }

    return [
      Column(
          children: widget.info.depends.map((x) {
        var (item, variant) = API.itemVariant(x);
        return ElevatedButton(
            onPressed: () {
              selectDependItems(context, x);
            },
            child:
                Text("Add ${API.API().getItem(item).variants[variant]!.name}"));
      }).toList()),
      const Divider(),
    ];
  }

  Widget flowContinuation() {
    return Row(
      mainAxisAlignment: MainAxisAlignment.center,
      children: [
        Card(
          child: Padding(
            padding: const EdgeInsets.all(8.0),
            child: Text(API.API().getFlowInfo(widget.previousFlow!.kind).name),
          ),
        ),
        const Card(child: Icon(Icons.arrow_right)),
        Card(
          child: Padding(
            padding: const EdgeInsets.all(8.0),
            child: Text(widget.info.name),
          ),
        )
      ],
    );
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
          title: Text(widget.previousFlow != null
              ? "Continue to ${widget.previousFlow!.kind}"
              : "Create new ${widget.info.name} Flow")),
      body: Column(
        children: [
          if (widget.previousFlow != null) ...[
            flowContinuation(),
            const Divider()
          ],
          ...buildInputSelection(context),
          Card(
              child: Column(
                  children: depends
                      .map((x) => TransactionCard(x, () {},
                          onTap: (x) {}, onLongPress: (x) {}))
                      .toList())),
          ElevatedButton(
              onPressed: () => _create(context),
              child: const Text("Create Flow"))
        ],
      ),
    );
  }
}