// Turns the in-memory hand history into a CSV file the dealer can download for a
// paper trail — a house manager or a disputed chip count needs something that
// outlives the browser tab, not just a scrollable panel in the sidebar.
const HandHistoryExport = {
    csvField(value) {
        const str = String(value ?? "");
        return /[",\n]/.test(str) ? `"${str.replace(/"/g, '""')}"` : str;
    },

    formatTimestamp(timestamp) {
        try {
            return new Date(timestamp).toLocaleString();
        } catch {
            return "";
        }
    },

    // Money columns go in as bare numbers. Written as "$1,250,000.00" they import as
    // text, so the one thing anybody opens this file to do — total a column and see
    // who owes what — doesn't work without cleaning every cell first. The commas were
    // quoted correctly, so the file parsed; it just wouldn't add up.
    toCsv(handHistory, standings = [], { notes = "" } = {}) {
        const rows = [["Hand #", "Time", "Pot", "Payouts"]];
        // handHistory is stored newest-first; the export reads better oldest-first.
        [...handHistory].reverse().forEach(entry => {
            const payouts = (entry.payouts || [])
                .map(p => `${p.label}: ${Money.format(p.amount)}`)
                .join("; ");
            rows.push([
                entry.handNumber,
                this.formatTimestamp(entry.timestamp),
                Money.forSheet(entry.pot),
                payouts,
            ]);
        });

        // The settle-up numbers go in the same file as the hands they came from, so a
        // dealer handing over one export isn't asked for a second one at cash-out.
        if (standings.length > 0) {
            rows.push([]);
            rows.push(["Session Standings"]);
            // Bought in and chips now are what a cash-out is settled from; paid in and
            // won describe the hands. Both belong in the file the dealer hands over.
            //
            // Notes go last so the money columns keep the shape a spreadsheet expects.
            // "IOU: $20 to Ann" is exactly the kind of thing that has to be in the file
            // somebody settles up from, and it was only ever visible inside that seat's
            // own editor.
            rows.push(["Player", "Paid In", "Won", "Net", "Bought In", "Chips Now", "Up/Down", "Notes"]);
            standings.forEach(row => {
                rows.push([
                    row.name,
                    Money.forSheet(row.in),
                    Money.forSheet(row.won),
                    Money.forSheet(row.net),
                    Money.forSheet(row.boughtIn || 0),
                    Money.forSheet(row.chipsNow || 0),
                    Money.forSheet(row.cashPosition || 0),
                    row.notes || "",
                ]);
            });

            // And the answer the standings are read to get to. Whoever opens this file
            // wants the payment list, not to redo the arithmetic in a spreadsheet.
            const plan = SettleUp.plan(standings);
            if (plan.payments.length > 0) {
                rows.push([]);
                rows.push(["Settle Up"]);
                rows.push(["Pays", "Receives", "Amount"]);
                plan.payments.forEach(payment => {
                    rows.push([payment.from, payment.to, Money.forSheet(payment.amount)]);
                });
                if (!plan.balanced) {
                    // The file is the paper trail, so the caveat travels with it rather
                    // than living only in a sidebar nobody exported.
                    rows.push([
                        plan.shortBy > 0
                            ? `Unpaid: ${Money.forSheet(plan.shortBy)} — more chips in play than cash taken`
                            : `Unclaimed: ${Money.forSheet(plan.overBy)} — more cash taken than chips in play`,
                    ]);
                }
            }
        }

        // The table's own notes — side bets, IOUs, the promo running until midnight.
        // The dealer typed them because they matter to the night, and the export is the
        // thing that outlives the browser tab; leaving them behind meant the one place
        // the context was written down was the one place it couldn't be handed over.
        // csvField quotes the line breaks, so a multi-line note survives as one cell.
        if (notes && notes.trim()) {
            rows.push([]);
            rows.push(["Table Notes"]);
            rows.push([notes.trim()]);
        }

        return rows.map(row => row.map(f => this.csvField(f)).join(",")).join("\r\n");
    },

    fileName() {
        const now = new Date();
        const pad = n => String(n).padStart(2, "0");
        const stamp = `${now.getFullYear()}-${pad(now.getMonth() + 1)}-${pad(now.getDate())}-${pad(now.getHours())}${pad(now.getMinutes())}`;
        return `holdem-hand-history-${stamp}.csv`;
    },

    download(handHistory, standings = [], options = {}) {
        const csv = this.toCsv(handHistory, standings, options);
        const blob = new Blob([csv], { type: "text/csv;charset=utf-8;" });
        const url = URL.createObjectURL(blob);
        const link = document.createElement("a");
        link.href = url;
        link.download = this.fileName();
        document.body.appendChild(link);
        link.click();
        document.body.removeChild(link);
        URL.revokeObjectURL(url);
    },
};

if (typeof module !== "undefined" && module.exports) {
    module.exports = HandHistoryExport;
}