// 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 "";
        }
    },

    toCsv(handHistory, standings = []) {
        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.format(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.
            rows.push(["Player", "Paid In", "Won", "Net", "Bought In", "Chips Now", "Up/Down"]);
            standings.forEach(row => {
                rows.push([
                    row.name,
                    Money.format(row.in),
                    Money.format(row.won),
                    Money.formatSigned(row.net),
                    Money.format(row.boughtIn || 0),
                    Money.format(row.chipsNow || 0),
                    Money.formatSigned(row.cashPosition || 0),
                ]);
            });
        }

        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 = []) {
        const csv = this.toCsv(handHistory, standings);
        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;
}