// Flutter
import 'package:flutter/material.dart';
import 'package:flutter_expense_tracker/models/item_type.dart';

// Local
import '/db.dart';
import '/models/tracked_item.dart';

/// TODO:
/// - Projected Assets in:
///     - 1 week, 1 month, 1 quarter, 1 year
///     - 1/2 year? 2 years? 5 years? Allow customization?

class ProjectionPage extends StatefulWidget {
  const ProjectionPage({
    super.key,
  });

  @override
  State<ProjectionPage> createState() => _ProjectionPageState();
}

class _ProjectionPageState extends State<ProjectionPage> {
  @override
  Widget build(BuildContext context) {
    Widget expenseSummary = SummaryCardForTotals(
      list: DatabaseHelper.instance.getExpenses(),
      summaryTypeLabel: ItemType.expense.title,
    );
    Widget incomeSummary = SummaryCardForTotals(
      list: DatabaseHelper.instance.getIncomes(),
      summaryTypeLabel: ItemType.income.title,
    );
    Widget assetSummary = SummaryCardForTotals(
      list: DatabaseHelper.instance.getAssets(),
      summaryTypeLabel: ItemType.asset.title,
    );

    return ListView(
      children: [
        expenseSummary,
        incomeSummary,
        assetSummary,
      ],
    );
  }
}

class SummaryCardForTotals extends StatelessWidget {
  const SummaryCardForTotals({
    super.key,
    required this.list,
    required this.summaryTypeLabel,
  });

  final Future<List<TrackedItem>> list;
  final String summaryTypeLabel;

  @override
  Widget build(BuildContext context) {
    return FutureBuilder<List<TrackedItem>>(
        future: list,
        builder: (
          BuildContext context,
          AsyncSnapshot<List<TrackedItem>> snapshot,
        ) {
          if (!snapshot.hasData) {
            return Text('Loading $summaryTypeLabel Section...');
          }

          // Calculate the total fields based on item type.
          double dailyTotal = 0, monthlyTotal = 0, yearlyTotal = 0;
          bool isAsset = false;
          for (TrackedItem e in snapshot.data!) {
            if (e.type == ItemType.asset) {
              monthlyTotal += e.amount;
              isAsset = true;
            } else {
              dailyTotal += e.calcComparableAmountDaily();
              monthlyTotal += e.calcComparableAmountYearly() / 12;
              yearlyTotal += e.calcComparableAmountYearly();
            }
          }

          /* Determine what needs displayed for the item type. */
          // Header
          String plural = snapshot.data!.length == 1 ? "" : "s";
          String header = "$summaryTypeLabel Total";
          header += isAsset ? "" : "s";
          header += " (${snapshot.data!.length} Item$plural)";

          // Total Fields
          String dailyEstimate =
                  dailyTotal.toStringAsFixed(3).endsWith("0") ? "" : "~",
              monthlyEstimate =
                  monthlyTotal.toStringAsFixed(3).endsWith("0") ? "" : "~",
              yearlyEstimate =
                  yearlyTotal.toStringAsFixed(3).endsWith("0") ? "" : "~";
          String leftText = "", middleText = "", rightText = "";
          if (isAsset) {
            middleText = "$monthlyEstimate${monthlyTotal.toStringAsFixed(2)}";
          } else {
            leftText = "$dailyEstimate${dailyTotal.toStringAsFixed(2)} Daily";
            middleText =
                "$monthlyEstimate${monthlyTotal.toStringAsFixed(2)} Monthly";
            rightText =
                "$yearlyEstimate${yearlyTotal.toStringAsFixed(2)} Yearly";
          }

          // Return the UI element.
          return SummaryCard(
            name: header,
            leftText: leftText,
            middleText: middleText,
            rightText: rightText,
          );
        });
  }
}

class SummaryCard extends StatelessWidget {
  const SummaryCard({
    super.key,
    required this.name,
    required this.leftText,
    required this.middleText,
    required this.rightText,
  });

  final String name;
  final String leftText;
  final String middleText;
  final String rightText;

  @override
  Widget build(BuildContext context) {
    return Card(
      color: Theme.of(context).cardColor,
      child: Padding(
        padding: const EdgeInsets.all(8.0),
        child: Card(
          color: Theme.of(context).highlightColor,
          child: Column(
            children: [
              Text(
                name,
                style: TextStyle(
                  decoration: TextDecoration.underline,
                  fontSize: 16,
                ),
              ),
              Row(
                children: [
                  Spacer(
                    flex: 3,
                  ),
                  Text(
                    leftText,
                  ),
                  Spacer(
                    flex: 1,
                  ),
                  Text(
                    middleText,
                  ),
                  Spacer(
                    flex: 1,
                  ),
                  Text(
                    rightText,
                  ),
                  Spacer(
                    flex: 3,
                  ),
                ],
              ),
            ],
          ),
        ),
      ),
    );
  }
}