const std = @import("std");
const zfin = @import("../root.zig");
const cli = @import("common.zig");
const fmt = cli.fmt;

pub fn run(allocator: std.mem.Allocator, svc: *zfin.DataService, config: zfin.Config, symbol: []const u8, color: bool, out: *std.Io.Writer) !void {
    const result = svc.getDividends(symbol) catch |err| switch (err) {
        zfin.DataError.NoApiKey => {
            try cli.stderrPrint("Error: POLYGON_API_KEY not set. Get a free key at https://polygon.io\n");
            return;
        },
        else => {
            try cli.stderrPrint("Error fetching dividend data.\n");
            return;
        },
    };
    defer allocator.free(result.data);

    if (result.source == .cached) try cli.stderrPrint("(using cached dividend data)\n");

    // Fetch current price for yield calculation
    var current_price: ?f64 = null;
    if (config.twelvedata_key) |td_key| {
        var td = zfin.TwelveData.init(allocator, td_key);
        defer td.deinit();
        if (td.fetchQuote(allocator, symbol)) |qr_val| {
            var qr = qr_val;
            defer qr.deinit();
            if (qr.parse(allocator)) |q_val| {
                var q = q_val;
                defer q.deinit();
                current_price = q.close();
            } else |_| {}
        } else |_| {}
    }

    try display(result.data, symbol, current_price, color, out);
}

pub fn display(dividends: []const zfin.Dividend, symbol: []const u8, current_price: ?f64, color: bool, out: *std.Io.Writer) !void {
    try cli.setBold(out, color);
    try out.print("\nDividend History for {s}\n", .{symbol});
    try cli.reset(out, color);
    try out.print("========================================\n", .{});

    if (dividends.len == 0) {
        try cli.setFg(out, color, cli.CLR_MUTED);
        try out.print("  No dividends found.\n\n", .{});
        try cli.reset(out, color);
        return;
    }

    try cli.setFg(out, color, cli.CLR_MUTED);
    try out.print("{s:>12} {s:>10} {s:>12} {s:>6} {s:>10}\n", .{
        "Ex-Date", "Amount", "Pay Date", "Freq", "Type",
    });
    try out.print("{s:->12} {s:->10} {s:->12} {s:->6} {s:->10}\n", .{
        "", "", "", "", "",
    });
    try cli.reset(out, color);

    const today = fmt.todayDate();
    const one_year_ago = today.subtractYears(1);
    var total: f64 = 0;
    var ttm: f64 = 0;

    for (dividends) |div| {
        var ex_buf: [10]u8 = undefined;
        try out.print("{s:>12} {d:>10.4}", .{ div.ex_date.format(&ex_buf), div.amount });
        if (div.pay_date) |pd| {
            var pay_buf: [10]u8 = undefined;
            try out.print(" {s:>12}", .{pd.format(&pay_buf)});
        } else {
            try out.print(" {s:>12}", .{"--"});
        }
        if (div.frequency) |f| {
            try out.print(" {d:>6}", .{f});
        } else {
            try out.print(" {s:>6}", .{"--"});
        }
        try out.print(" {s:>10}\n", .{@tagName(div.distribution_type)});
        total += div.amount;
        if (!div.ex_date.lessThan(one_year_ago)) ttm += div.amount;
    }

    try out.print("\n{d} dividends, total: ${d:.4}\n", .{ dividends.len, total });
    try cli.setFg(out, color, cli.CLR_ACCENT);
    try out.print("TTM dividends: ${d:.4}", .{ttm});
    if (current_price) |cp| {
        if (cp > 0) {
            const yield = (ttm / cp) * 100.0;
            try out.print("  (yield: {d:.2}% at ${d:.2})", .{ yield, cp });
        }
    }
    try cli.reset(out, color);
    try out.print("\n\n", .{});
}

// ── Tests ────────────────────────────────────────────────────

test "display shows dividend data with yield" {
    var buf: [4096]u8 = undefined;
    var w: std.Io.Writer = .fixed(&buf);
    const divs = [_]zfin.Dividend{
        .{ .ex_date = .{ .days = 20000 }, .amount = 0.88, .distribution_type = .regular },
        .{ .ex_date = .{ .days = 19900 }, .amount = 0.88, .distribution_type = .regular },
    };
    try display(&divs, "VTI", 250.0, false, &w);
    const out = w.buffered();
    try std.testing.expect(std.mem.indexOf(u8, out, "VTI") != null);
    try std.testing.expect(std.mem.indexOf(u8, out, "0.8800") != null);
    try std.testing.expect(std.mem.indexOf(u8, out, "2 dividends") != null);
    try std.testing.expect(std.mem.indexOf(u8, out, "TTM") != null);
    try std.testing.expect(std.mem.indexOf(u8, out, "yield") != null);
}

test "display shows empty message" {
    var buf: [4096]u8 = undefined;
    var w: std.Io.Writer = .fixed(&buf);
    const divs = [_]zfin.Dividend{};
    try display(&divs, "BRK.A", null, false, &w);
    const out = w.buffered();
    try std.testing.expect(std.mem.indexOf(u8, out, "No dividends found") != null);
}

test "display without price omits yield" {
    var buf: [4096]u8 = undefined;
    var w: std.Io.Writer = .fixed(&buf);
    const divs = [_]zfin.Dividend{
        .{ .ex_date = .{ .days = 20000 }, .amount = 1.50, .distribution_type = .regular },
    };
    try display(&divs, "T", null, false, &w);
    const out = w.buffered();
    try std.testing.expect(std.mem.indexOf(u8, out, "yield") == null);
    try std.testing.expect(std.mem.indexOf(u8, out, "1 dividends") != null);
}

test "display no ANSI without color" {
    var buf: [4096]u8 = undefined;
    var w: std.Io.Writer = .fixed(&buf);
    const divs = [_]zfin.Dividend{
        .{ .ex_date = .{ .days = 20000 }, .amount = 0.50, .distribution_type = .regular },
    };
    try display(&divs, "SPY", 500.0, false, &w);
    const out = w.buffered();
    try std.testing.expect(std.mem.indexOf(u8, out, "\x1b[") == null);
}