//! Progress Bar Demo - Shows progress with ETA
//!
//! Run with: zig build progress-demo

const std = @import("std");
const zcatui = @import("zcatui");

const Terminal = zcatui.Terminal;
const Rect = zcatui.Rect;
const Buffer = zcatui.Buffer;
const Style = zcatui.Style;
const Color = zcatui.Color;
const Block = zcatui.widgets.Block;
const Borders = zcatui.widgets.Borders;

const Task = struct {
    name: []const u8,
    current: u64,
    total: u64,
    speed: f64, // Items per frame
    color: Color,
};

/// State for the demo
const State = struct {
    tasks: [4]Task = .{
        .{ .name = "Downloading...", .current = 0, .total = 100, .speed = 0.8, .color = Color.blue },
        .{ .name = "Compiling...", .current = 0, .total = 50, .speed = 0.3, .color = Color.green },
        .{ .name = "Installing...", .current = 0, .total = 200, .speed = 1.2, .color = Color.yellow },
        .{ .name = "Verifying...", .current = 0, .total = 80, .speed = 0.5, .color = Color.magenta },
    },
    frame: u64 = 0,
    paused: bool = false,
    running: bool = true,
};

pub fn main() !void {
    var gpa = std.heap.GeneralPurposeAllocator(.{}){};
    defer _ = gpa.deinit();
    const allocator = gpa.allocator();

    var term = try Terminal.init(allocator);
    defer term.deinit();

    var state = State{};

    while (state.running) {
        try term.drawWithContext(&state, render);

        if (try term.pollEvent(50)) |event| {
            switch (event) {
                .key => |key| {
                    switch (key.code) {
                        .char => |c| {
                            if (c == 'q') state.running = false;
                            if (c == 'r') {
                                // Reset all tasks
                                for (&state.tasks) |*task| {
                                    task.current = 0;
                                }
                                state.frame = 0;
                            }
                            if (c == 'p' or c == ' ') state.paused = !state.paused;
                        },
                        .esc => state.running = false,
                        else => {},
                    }
                },
                else => {},
            }
        }

        // Update progress (simulate work)
        if (!state.paused) {
            for (&state.tasks) |*task| {
                if (task.current < task.total) {
                    // Add randomness to speed
                    const variation = @as(f64, @floatFromInt(state.frame % 10)) / 20.0;
                    const effective_speed = task.speed * (0.8 + variation);
                    const increment: u64 = @intFromFloat(effective_speed);
                    task.current = @min(task.current + @max(increment, 1), task.total);
                }
            }
        }

        state.frame +%= 1;
    }
}

fn render(state: *State, area: Rect, buf: *Buffer) void {
    // Main border
    const status_text = if (state.paused) " Progress Demo [PAUSED] " else " Progress Demo ";
    const block = Block.init()
        .title(status_text)
        .setBorders(Borders.all)
        .borderStyle((Style{}).fg(Color.cyan));
    block.render(area, buf);

    // Calculate total progress
    var total_current: u64 = 0;
    var total_total: u64 = 0;
    for (state.tasks) |task| {
        total_current += task.current;
        total_total += task.total;
    }

    // Overall progress at top
    const overall_y: u16 = 2;
    _ = buf.setString(2, overall_y, "Overall Progress:", (Style{}).fg(Color.white).bold());

    const overall_pct = if (total_total > 0) total_current * 100 / total_total else 0;
    const overall_bar_width = area.width -| 6;
    const overall_filled = @as(u16, @intCast(overall_bar_width * overall_pct / 100));

    // Draw overall progress bar
    var i: u16 = 0;
    while (i < overall_bar_width) : (i += 1) {
        const char: []const u8 = if (i < overall_filled) "=" else "-";
        const col = if (i < overall_filled) Color.cyan else Color.rgb(60, 60, 60);
        _ = buf.setString(2 + i, overall_y + 1, char, (Style{}).fg(col));
    }

    // Overall percentage
    var pct_buf: [16]u8 = undefined;
    const pct_str = std.fmt.bufPrint(&pct_buf, " {d}%", .{overall_pct}) catch "?%";
    _ = buf.setString(2 + overall_bar_width -| 5, overall_y + 1, pct_str, (Style{}).fg(Color.white).bold());

    // Individual task progress
    var y: u16 = overall_y + 4;
    for (state.tasks) |task| {
        if (y >= area.height -| 3) break;

        // Task name
        _ = buf.setString(2, y, task.name, (Style{}).fg(task.color));

        // Progress bar
        const bar_width = area.width -| 30;
        const pct = if (task.total > 0) task.current * 100 / task.total else 0;
        const filled = @as(u16, @intCast(bar_width * pct / 100));

        var j: u16 = 0;
        while (j < bar_width) : (j += 1) {
            const char: []const u8 = if (j < filled) "=" else "-";
            const col = if (j < filled) task.color else Color.rgb(60, 60, 60);
            _ = buf.setString(18 + j, y, char, (Style{}).fg(col));
        }

        // Stats
        var stats_buf: [32]u8 = undefined;
        const stats = std.fmt.bufPrint(&stats_buf, "{d}/{d} ({d}%)", .{
            task.current,
            task.total,
            pct,
        }) catch "...";
        _ = buf.setString(area.width -| 18, y, stats, (Style{}).fg(Color.white));

        y += 2;
    }

    // Completion message
    if (total_current >= total_total) {
        const msg = "All tasks completed!";
        const msg_x = (area.width -| @as(u16, @intCast(msg.len))) / 2;
        _ = buf.setString(msg_x, y + 1, msg, (Style{}).fg(Color.green).bold());
    }

    // Footer
    const help = if (state.paused)
        "SPACE/p resume | r restart | q quit"
    else
        "SPACE/p pause | r restart | q quit";
    _ = buf.setString(
        2,
        area.height -| 1,
        help,
        (Style{}).fg(Color.rgb(100, 100, 100)),
    );
}