//! Checkbox Widget - Boolean toggle
//!
//! A checkbox that toggles between checked and unchecked states.
//! Returns true when the state changes.

const std = @import("std");
const Context = @import("../core/context.zig").Context;
const Command = @import("../core/command.zig");
const Layout = @import("../core/layout.zig");
const Style = @import("../core/style.zig");
const Input = @import("../core/input.zig");

/// Checkbox configuration
pub const CheckboxConfig = struct {
    /// Label text
    label: []const u8 = "",
    /// Disabled state
    disabled: bool = false,
    /// Size of the checkbox box
    box_size: u32 = 16,
    /// Gap between box and label
    gap: u32 = 8,
};

/// Draw a checkbox and return true if state changed
pub fn checkbox(ctx: *Context, checked: *bool, label_text: []const u8) bool {
    return checkboxEx(ctx, checked, .{ .label = label_text });
}

/// Draw a checkbox with custom configuration
pub fn checkboxEx(ctx: *Context, checked: *bool, config: CheckboxConfig) bool {
    const bounds = ctx.layout.nextRect();
    return checkboxRect(ctx, bounds, checked, config);
}

/// Draw a checkbox in a specific rectangle
pub fn checkboxRect(
    ctx: *Context,
    bounds: Layout.Rect,
    checked: *bool,
    config: CheckboxConfig,
) bool {
    if (bounds.isEmpty()) return false;

    const id = ctx.getId(config.label);
    _ = id;

    // Check mouse interaction
    const mouse = ctx.input.mousePos();
    const hovered = bounds.contains(mouse.x, mouse.y) and !config.disabled;
    const clicked = hovered and ctx.input.mouseReleased(.left);

    // Toggle on click
    var changed = false;
    if (clicked) {
        checked.* = !checked.*;
        changed = true;
    }

    // Theme colors
    const theme = Style.Theme.dark;

    // Calculate box position (vertically centered)
    const box_y = bounds.y + @as(i32, @intCast((bounds.h -| config.box_size) / 2));

    // Determine box colors
    const box_bg = if (config.disabled)
        theme.secondary.darken(20)
    else if (checked.*)
        theme.primary
    else if (hovered)
        theme.input_bg.lighten(10)
    else
        theme.input_bg;

    const box_border = if (config.disabled)
        theme.border.darken(20)
    else if (hovered)
        theme.primary
    else
        theme.border;

    // Draw checkbox box
    ctx.pushCommand(Command.rect(
        bounds.x,
        box_y,
        config.box_size,
        config.box_size,
        box_bg,
    ));

    ctx.pushCommand(Command.rectOutline(
        bounds.x,
        box_y,
        config.box_size,
        config.box_size,
        box_border,
    ));

    // Draw checkmark if checked
    if (checked.*) {
        const check_margin: u32 = 4;
        const check_size = config.box_size -| (check_margin * 2);
        const check_x = bounds.x + @as(i32, @intCast(check_margin));
        const check_y = box_y + @as(i32, @intCast(check_margin));

        // Simple checkmark: draw two lines
        const check_color = Style.Color.white;

        // Line 1: bottom-left to middle-bottom
        ctx.pushCommand(Command.line(
            check_x + 2,
            check_y + @as(i32, @intCast(check_size / 2)),
            check_x + @as(i32, @intCast(check_size / 2)),
            check_y + @as(i32, @intCast(check_size)) - 2,
            check_color,
        ));

        // Line 2: middle-bottom to top-right
        ctx.pushCommand(Command.line(
            check_x + @as(i32, @intCast(check_size / 2)),
            check_y + @as(i32, @intCast(check_size)) - 2,
            check_x + @as(i32, @intCast(check_size)) - 2,
            check_y + 2,
            check_color,
        ));
    }

    // Draw label if present
    if (config.label.len > 0) {
        const label_x = bounds.x + @as(i32, @intCast(config.box_size + config.gap));
        const char_height: u32 = 8;
        const label_y = bounds.y + @as(i32, @intCast((bounds.h -| char_height) / 2));

        const label_color = if (config.disabled)
            theme.foreground.darken(40)
        else
            theme.foreground;

        ctx.pushCommand(Command.text(label_x, label_y, config.label, label_color));
    }

    return changed;
}

// =============================================================================
// Tests
// =============================================================================

test "checkbox toggle" {
    var ctx = try Context.init(std.testing.allocator, 800, 600);
    defer ctx.deinit();

    var checked = false;

    // Frame 1: Click inside checkbox
    ctx.beginFrame();
    ctx.layout.row_height = 24;
    ctx.input.setMousePos(8, 12);
    ctx.input.setMouseButton(.left, true);
    _ = checkbox(&ctx, &checked, "Option");
    ctx.endFrame();

    // Frame 2: Release inside checkbox
    ctx.beginFrame();
    ctx.layout.row_height = 24;
    ctx.input.setMousePos(8, 12);
    ctx.input.setMouseButton(.left, false);
    const changed = checkbox(&ctx, &checked, "Option");
    ctx.endFrame();

    try std.testing.expect(changed);
    try std.testing.expect(checked);
}

test "checkbox generates commands" {
    var ctx = try Context.init(std.testing.allocator, 800, 600);
    defer ctx.deinit();

    var checked = true;

    ctx.beginFrame();
    ctx.layout.row_height = 24;

    _ = checkbox(&ctx, &checked, "With label");

    // Should generate: rect (box) + rect_outline (border) + 2 lines (checkmark) + text (label)
    try std.testing.expect(ctx.commands.items.len >= 4);

    ctx.endFrame();
}

test "checkbox disabled no toggle" {
    var ctx = try Context.init(std.testing.allocator, 800, 600);
    defer ctx.deinit();

    var checked = false;

    // Frame 1: Click
    ctx.beginFrame();
    ctx.layout.row_height = 24;
    ctx.input.setMousePos(8, 12);
    ctx.input.setMouseButton(.left, true);
    _ = checkboxEx(&ctx, &checked, .{ .label = "Disabled", .disabled = true });
    ctx.endFrame();

    // Frame 2: Release
    ctx.beginFrame();
    ctx.layout.row_height = 24;
    ctx.input.setMousePos(8, 12);
    ctx.input.setMouseButton(.left, false);
    const changed = checkboxEx(&ctx, &checked, .{ .label = "Disabled", .disabled = true });
    ctx.endFrame();

    try std.testing.expect(!changed);
    try std.testing.expect(!checked);
}