Receipts: Historical stats command

commands/receipts/receiptCommands.js

@@ -29,6 +29,11 @@ module.exports = {
                         .setDescription('Show spendings from the previous budget cycle instead of the current one')
                         .setRequired(false)
                 )
+        )
+        .addSubcommand(subcommand =>
+            subcommand
+                .setName('stats')
+                .setDescription('View detailed spending and savings statistics')
         ),
     async execute(interaction) {
         console.log('budget command entrypoint');
@@ -100,6 +105,47 @@ module.exports = {
 
                 await interaction.reply({ embeds: [budgetEmbed] });
                 break
+            case 'stats':
+                const allBudgets = db.prepare(`
+                    SELECT id, budget_amount, exchange_rate, start_date, end_date 
+                    FROM weekly_budgets 
+                    ORDER BY start_date DESC
+                    LIMIT 4
+                `).all();
+
+                let statsDescription = "";
+                let cumulativeSavingsEur = 0;
+
+                for (const budgetPeriod of allBudgets) {
+                    const periodSpendings = db.prepare(`
+                        SELECT amount 
+                        FROM grocery_spendings 
+                        WHERE budget_id = ? AND discord_id = ?
+                    `).all(budgetPeriod.id, interaction.member.id);
+
+                    const totalSpentInPeriodEur = periodSpendings.reduce((acc, s) => acc + s.amount, 0);
+                    const savedInPeriodEur = budgetPeriod.budget_amount - totalSpentInPeriodEur;
+                    cumulativeSavingsEur += savedInPeriodEur;
+
+                    statsDescription += `**Period: ${budgetPeriod.start_date} - ${budgetPeriod.end_date}**\n`;
+                    statsDescription += `Budget: ${budgetPeriod.budget_amount.toFixed(2)}€\n`;
+                    statsDescription += `Spent: ${totalSpentInPeriodEur.toFixed(2)}€ (${(totalSpentInPeriodEur * budgetPeriod.exchange_rate).toFixed(2)} kr)\n`;
+                    statsDescription += `Saved: ${savedInPeriodEur.toFixed(2)}€ (${(savedInPeriodEur * budgetPeriod.exchange_rate).toFixed(2)} kr)\n`;
+                    statsDescription += `Cumulative: ${cumulativeSavingsEur.toFixed(2)}€\n\n`;
+                }
+
+                if (allBudgets.length === 0) {
+                    statsDescription = "No budget periods on record.";
+                }
+
+                const statsEmbed = new EmbedBuilder()
+                    .setColor(0x0099ff)
+                    .setTitle(`${interaction.member.displayName}'s Budget Statistics`)
+                    .setDescription(statsDescription)
+                    .setTimestamp();
+
+                await interaction.reply({ embeds: [statsEmbed] });
+                break;
             default:
                 await interaction.reply(`Sub mismatch. Switching on ${interaction.options.getSubcommand()}`);
                 break;