//! IconButton Widget - Circular button with icon
//!
//! A button that displays only an icon, typically circular.
//! Commonly used in toolbars, app bars, and action buttons.

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");
const icon_module = @import("icon.zig");

/// IconButton style variants
pub const ButtonStyle = enum {
    /// Filled background (primary action)
    filled,
    /// Outlined with border
    outlined,
    /// Ghost (transparent, only visible on hover)
    ghost,
    /// Tonal (subtle background)
    tonal,
};

/// IconButton size presets
pub const Size = enum {
    /// 24x24 button (16x16 icon)
    small,
    /// 36x36 button (20x20 icon)
    medium,
    /// 48x48 button (24x24 icon)
    large,
    /// 56x56 button (32x32 icon)
    xlarge,

    pub fn buttonSize(self: Size) u32 {
        return switch (self) {
            .small => 24,
            .medium => 36,
            .large => 48,
            .xlarge => 56,
        };
    }

    pub fn iconSize(self: Size) u32 {
        return switch (self) {
            .small => 16,
            .medium => 20,
            .large => 24,
            .xlarge => 32,
        };
    }
};

/// IconButton configuration
pub const Config = struct {
    /// Icon to display
    icon_type: icon_module.IconType,
    /// Button size
    size: Size = .medium,
    /// Button style
    style: ButtonStyle = .ghost,
    /// Tooltip text (shown on hover)
    tooltip: ?[]const u8 = null,
    /// Disabled state
    disabled: bool = false,
    /// Selected/active state (for toggle buttons)
    selected: bool = false,
    /// Badge text (small indicator)
    badge: ?[]const u8 = null,
};

/// IconButton colors
pub const Colors = struct {
    /// Icon color (normal)
    icon: Style.Color = Style.Color.rgba(220, 220, 220, 255),
    /// Icon color (hovered)
    icon_hover: Style.Color = Style.Color.white,
    /// Icon color (disabled)
    icon_disabled: Style.Color = Style.Color.rgba(100, 100, 100, 255),
    /// Background (filled style)
    background: Style.Color = Style.Color.rgba(66, 133, 244, 255),
    /// Background (hovered)
    background_hover: Style.Color = Style.Color.rgba(86, 153, 255, 255),
    /// Background (pressed)
    background_pressed: Style.Color = Style.Color.rgba(46, 113, 224, 255),
    /// Border color (outlined style)
    border: Style.Color = Style.Color.rgba(100, 100, 100, 255),
    /// Ghost hover background
    ghost_hover: Style.Color = Style.Color.rgba(255, 255, 255, 20),
    /// Selected background
    selected_bg: Style.Color = Style.Color.rgba(66, 133, 244, 50),
    /// Badge background
    badge_bg: Style.Color = Style.Color.rgba(244, 67, 54, 255),
    /// Badge text
    badge_text: Style.Color = Style.Color.white,

    pub fn fromTheme(theme: Style.Theme) Colors {
        return .{
            .icon = theme.foreground,
            .icon_hover = theme.foreground.lighten(20),
            .icon_disabled = theme.foreground.darken(40),
            .background = theme.primary,
            .background_hover = theme.primary.lighten(10),
            .background_pressed = theme.primary.darken(10),
            .border = theme.border,
            .ghost_hover = theme.foreground.withAlpha(20),
            .selected_bg = theme.primary.withAlpha(50),
            .badge_bg = theme.danger,
            .badge_text = Style.Color.white,
        };
    }
};

/// IconButton result
pub const Result = struct {
    /// True if button was clicked this frame
    clicked: bool,
    /// True if button is currently hovered
    hovered: bool,
    /// True if button is currently pressed
    pressed: bool,
    /// Bounding rectangle of the button
    bounds: Layout.Rect,
};

/// Simple icon button
pub fn iconButton(ctx: *Context, icon_type: icon_module.IconType) Result {
    return iconButtonEx(ctx, .{ .icon_type = icon_type }, .{});
}

/// Icon button with tooltip
pub fn iconButtonTooltip(ctx: *Context, icon_type: icon_module.IconType, tooltip_text: []const u8) Result {
    return iconButtonEx(ctx, .{ .icon_type = icon_type, .tooltip = tooltip_text }, .{});
}

/// Icon button with full configuration
pub fn iconButtonEx(ctx: *Context, config: Config, colors: Colors) Result {
    const btn_size = config.size.buttonSize();

    // Get bounds from layout
    var bounds = ctx.layout.nextRect();
    // Override size if layout gives us something different
    if (bounds.w != btn_size or bounds.h != btn_size) {
        bounds.w = btn_size;
        bounds.h = btn_size;
    }

    return iconButtonRect(ctx, bounds, config, colors);
}

/// Icon button in a specific rectangle
pub fn iconButtonRect(
    ctx: *Context,
    bounds: Layout.Rect,
    config: Config,
    colors: Colors,
) Result {
    if (bounds.isEmpty()) {
        return .{
            .clicked = false,
            .hovered = false,
            .pressed = false,
            .bounds = bounds,
        };
    }

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

    // Determine background color
    const bg_color: ?Style.Color = switch (config.style) {
        .filled => if (config.disabled)
            colors.background.darken(30)
        else if (pressed)
            colors.background_pressed
        else if (hovered)
            colors.background_hover
        else
            colors.background,
        .outlined => if (hovered or config.selected)
            colors.ghost_hover
        else
            null,
        .ghost => if (pressed)
            colors.ghost_hover.withAlpha(40)
        else if (hovered or config.selected)
            colors.ghost_hover
        else
            null,
        .tonal => if (config.disabled)
            colors.ghost_hover.darken(20)
        else if (pressed)
            colors.ghost_hover.withAlpha(60)
        else if (hovered)
            colors.ghost_hover.withAlpha(40)
        else
            colors.ghost_hover.withAlpha(25),
    };

    // Draw background (circular approximation with rounded rect)
    if (bg_color) |bg| {
        ctx.pushCommand(Command.rect(bounds.x, bounds.y, bounds.w, bounds.h, bg));
    }

    // Draw border for outlined style
    if (config.style == .outlined) {
        ctx.pushCommand(Command.rectOutline(bounds.x, bounds.y, bounds.w, bounds.h, colors.border));
    }

    // Draw selected indicator
    if (config.selected and config.style != .filled) {
        ctx.pushCommand(Command.rect(bounds.x, bounds.y, bounds.w, bounds.h, colors.selected_bg));
    }

    // Draw icon
    const icon_size = config.size.iconSize();
    const icon_x = bounds.x + @as(i32, @intCast((bounds.w - icon_size) / 2));
    const icon_y = bounds.y + @as(i32, @intCast((bounds.h - icon_size) / 2));

    const icon_color = if (config.disabled)
        colors.icon_disabled
    else if (hovered and config.style != .filled)
        colors.icon_hover
    else if (config.style == .filled)
        Style.Color.white
    else
        colors.icon;

    const icon_rect = Layout.Rect{
        .x = icon_x,
        .y = icon_y,
        .w = icon_size,
        .h = icon_size,
    };

    icon_module.iconRect(ctx, icon_rect, config.icon_type, .{
        .custom_size = icon_size,
    }, .{
        .foreground = icon_color,
    });

    // Draw badge
    if (config.badge) |badge_text| {
        if (badge_text.len > 0) {
            const badge_size: u32 = if (badge_text.len == 1) 16 else @as(u32, @intCast(badge_text.len * 6 + 8));
            const badge_x = bounds.x + @as(i32, @intCast(bounds.w)) - @as(i32, @intCast(badge_size / 2)) - 2;
            const badge_y = bounds.y - @as(i32, @intCast(badge_size / 2)) + 4;

            // Badge background
            ctx.pushCommand(Command.rect(badge_x, badge_y, badge_size, 16, colors.badge_bg));
            // Badge text
            ctx.pushCommand(Command.text(badge_x + 4, badge_y + 4, badge_text, colors.badge_text));
        }
    }

    // Tooltip is handled externally by the tooltip widget
    // The caller should check if hovered and show tooltip

    return .{
        .clicked = clicked,
        .hovered = hovered,
        .pressed = pressed,
        .bounds = bounds,
    };
}

/// Create a row of icon buttons (toolbar style)
pub fn iconButtonRow(
    ctx: *Context,
    buttons: []const Config,
    colors: Colors,
    spacing: u16,
) []Result {
    // This is a convenience function - in practice you'd want to allocate
    // For now, we just draw them and return the last result
    var last_x = ctx.layout.current_x;

    for (buttons) |config| {
        const btn_size = config.size.buttonSize();
        const bounds = Layout.Rect{
            .x = last_x,
            .y = ctx.layout.current_y,
            .w = btn_size,
            .h = btn_size,
        };

        _ = iconButtonRect(ctx, bounds, config, colors);
        last_x += @as(i32, @intCast(btn_size + spacing));
    }

    // Return empty slice - caller should call individually if they need results
    return &.{};
}

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

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

    // Frame 1: Press inside button
    ctx.beginFrame();
    ctx.layout.row_height = 36;
    ctx.input.setMousePos(18, 18); // Center of 36x36 button
    ctx.input.setMouseButton(.left, true);
    _ = iconButton(&ctx, .check);
    ctx.endFrame();

    // Frame 2: Release
    ctx.beginFrame();
    ctx.layout.row_height = 36;
    ctx.input.setMousePos(18, 18);
    ctx.input.setMouseButton(.left, false);
    const result = iconButton(&ctx, .check);
    ctx.endFrame();

    try std.testing.expect(result.clicked);
}

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

    // Frame 1: Press
    ctx.beginFrame();
    ctx.layout.row_height = 36;
    ctx.input.setMousePos(18, 18);
    ctx.input.setMouseButton(.left, true);
    _ = iconButtonEx(&ctx, .{ .icon_type = .check, .disabled = true }, .{});
    ctx.endFrame();

    // Frame 2: Release
    ctx.beginFrame();
    ctx.layout.row_height = 36;
    ctx.input.setMousePos(18, 18);
    ctx.input.setMouseButton(.left, false);
    const result = iconButtonEx(&ctx, .{ .icon_type = .check, .disabled = true }, .{});
    ctx.endFrame();

    try std.testing.expect(!result.clicked);
}

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

    ctx.beginFrame();
    ctx.layout.row_height = 36;

    _ = iconButtonEx(&ctx, .{
        .icon_type = .settings,
        .style = .filled,
    }, .{});

    // Should generate: background rect + icon lines
    try std.testing.expect(ctx.commands.items.len >= 2);

    ctx.endFrame();
}

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

    ctx.beginFrame();
    ctx.layout.row_height = 36;

    _ = iconButtonEx(&ctx, .{
        .icon_type = .bell,
        .badge = "3",
    }, .{});

    // Should generate: icon + badge background + badge text
    try std.testing.expect(ctx.commands.items.len >= 3);

    ctx.endFrame();
}

test "iconButton sizes" {
    try std.testing.expectEqual(@as(u32, 24), Size.small.buttonSize());
    try std.testing.expectEqual(@as(u32, 36), Size.medium.buttonSize());
    try std.testing.expectEqual(@as(u32, 48), Size.large.buttonSize());
    try std.testing.expectEqual(@as(u32, 56), Size.xlarge.buttonSize());

    try std.testing.expectEqual(@as(u32, 16), Size.small.iconSize());
    try std.testing.expectEqual(@as(u32, 20), Size.medium.iconSize());
    try std.testing.expectEqual(@as(u32, 24), Size.large.iconSize());
    try std.testing.expectEqual(@as(u32, 32), Size.xlarge.iconSize());
}