//! Tooltip widget for zcatui.
//!
//! Provides hover-style information popups:
//! - Tooltip: Simple text tooltip
//! - TooltipManager: Manages tooltip timing and positioning
//!
//! ## Example
//!
//! ```zig
//! var tooltip = Tooltip.init("Click to save your document")
//!     .setStyle(Style.default.bg(Color.yellow).fg(Color.black));
//!
//! // Show at position
//! tooltip.showAt(mouse_x, mouse_y);
//! tooltip.render(area, buf);
//! ```

const std = @import("std");
const buffer_mod = @import("../buffer.zig");
const Buffer = buffer_mod.Buffer;
const Rect = buffer_mod.Rect;
const style_mod = @import("../style.zig");
const Style = style_mod.Style;
const Color = style_mod.Color;
const block_mod = @import("block.zig");
const Block = block_mod.Block;
const Borders = block_mod.Borders;

// ============================================================================
// Tooltip
// ============================================================================

/// Position of tooltip relative to target.
pub const TooltipPosition = enum {
    above,
    below,
    left,
    right,
    auto, // Automatically choose best position
};

/// A simple tooltip widget.
pub const Tooltip = struct {
    /// Tooltip text (single line).
    text: []const u8 = "",

    /// Multi-line text (if set, overrides single text).
    lines: []const []const u8 = &.{},

    /// Position relative to anchor point.
    x: u16 = 0,
    y: u16 = 0,

    /// Whether tooltip is visible.
    visible: bool = false,

    /// Preferred position relative to anchor.
    position: TooltipPosition = .auto,

    /// Style for tooltip background and text.
    style: Style = Style.default.bg(Color.yellow).fg(Color.black),

    /// Border style (null = no border).
    border: bool = true,
    border_style: Style = Style.default.fg(Color.black),

    /// Padding inside tooltip.
    padding_x: u16 = 1,
    padding_y: u16 = 0,

    /// Maximum width (0 = no limit).
    max_width: u16 = 60,

    /// Arrow indicator character.
    show_arrow: bool = false,

    /// Creates a new tooltip with text.
    pub fn init(text: []const u8) Tooltip {
        return .{
            .text = text,
        };
    }

    /// Creates a tooltip with multiple lines.
    pub fn initMultiline(lines: []const []const u8) Tooltip {
        return .{
            .lines = lines,
        };
    }

    /// Sets the text.
    pub fn setText(self: Tooltip, text: []const u8) Tooltip {
        var t = self;
        t.text = text;
        t.lines = &.{};
        return t;
    }

    /// Sets multiple lines.
    pub fn setLines(self: Tooltip, lines: []const []const u8) Tooltip {
        var t = self;
        t.lines = lines;
        return t;
    }

    /// Sets the style.
    pub fn setStyle(self: Tooltip, style: Style) Tooltip {
        var t = self;
        t.style = style;
        return t;
    }

    /// Sets the border.
    pub fn setBorder(self: Tooltip, border: bool) Tooltip {
        var t = self;
        t.border = border;
        return t;
    }

    /// Sets the border style.
    pub fn setBorderStyle(self: Tooltip, style: Style) Tooltip {
        var t = self;
        t.border_style = style;
        return t;
    }

    /// Sets the preferred position.
    pub fn setPosition(self: Tooltip, pos: TooltipPosition) Tooltip {
        var t = self;
        t.position = pos;
        return t;
    }

    /// Sets maximum width.
    pub fn setMaxWidth(self: Tooltip, width: u16) Tooltip {
        var t = self;
        t.max_width = width;
        return t;
    }

    /// Shows the tooltip at a specific position.
    pub fn showAt(self: *Tooltip, x: u16, y: u16) void {
        self.x = x;
        self.y = y;
        self.visible = true;
    }

    /// Shows the tooltip near an anchor point with offset.
    pub fn showNear(self: *Tooltip, anchor_x: u16, anchor_y: u16, bounds: Rect) void {
        const size = self.calculateSize();

        // Calculate position based on preference
        var tx: u16 = anchor_x;
        var ty: u16 = anchor_y;

        switch (self.position) {
            .above => {
                ty = anchor_y -| size.height -| 1;
            },
            .below => {
                ty = anchor_y + 1;
            },
            .left => {
                tx = anchor_x -| size.width -| 1;
            },
            .right => {
                tx = anchor_x + 1;
            },
            .auto => {
                // Try below first, then above
                if (anchor_y + 1 + size.height <= bounds.height) {
                    ty = anchor_y + 1;
                } else if (anchor_y >= size.height + 1) {
                    ty = anchor_y -| size.height -| 1;
                } else {
                    ty = anchor_y + 1;
                }
            },
        }

        // Adjust to fit within bounds
        if (tx + size.width > bounds.x + bounds.width) {
            tx = bounds.x + bounds.width -| size.width;
        }
        if (ty + size.height > bounds.y + bounds.height) {
            ty = bounds.y + bounds.height -| size.height;
        }

        self.x = tx;
        self.y = ty;
        self.visible = true;
    }

    /// Hides the tooltip.
    pub fn hide(self: *Tooltip) void {
        self.visible = false;
    }

    /// Returns whether visible.
    pub fn isVisible(self: Tooltip) bool {
        return self.visible;
    }

    /// Calculates the size of the tooltip.
    pub fn calculateSize(self: Tooltip) struct { width: u16, height: u16 } {
        var content_width: u16 = 0;
        var content_height: u16 = 0;

        if (self.lines.len > 0) {
            for (self.lines) |line| {
                const line_len: u16 = @intCast(@min(line.len, 65535));
                content_width = @max(content_width, line_len);
            }
            content_height = @intCast(self.lines.len);
        } else {
            content_width = @intCast(@min(self.text.len, 65535));
            content_height = 1;
        }

        // Apply max width
        if (self.max_width > 0 and content_width > self.max_width) {
            content_width = self.max_width;
        }

        // Add padding
        var width = content_width + self.padding_x * 2;
        var height = content_height + self.padding_y * 2;

        // Add border
        if (self.border) {
            width += 2;
            height += 2;
        }

        return .{ .width = width, .height = height };
    }

    /// Gets the tooltip area.
    pub fn getArea(self: Tooltip) Rect {
        const size = self.calculateSize();
        return Rect.init(self.x, self.y, size.width, size.height);
    }

    /// Renders the tooltip.
    pub fn render(self: Tooltip, bounds: Rect, buf: *Buffer) void {
        if (!self.visible) return;

        const size = self.calculateSize();
        const tooltip_area = Rect.init(
            @min(self.x, bounds.x + bounds.width -| size.width),
            @min(self.y, bounds.y + bounds.height -| size.height),
            size.width,
            size.height,
        );

        // Render background
        self.fillBackground(tooltip_area, buf);

        // Render border if enabled
        var content_area = tooltip_area;
        if (self.border) {
            const block = Block.init()
                .setBorders(Borders.all)
                .style(self.border_style);
            block.render(tooltip_area, buf);
            content_area = block.inner(tooltip_area);
        }

        // Apply padding
        const text_area = Rect.init(
            content_area.x + self.padding_x,
            content_area.y + self.padding_y,
            content_area.width -| self.padding_x * 2,
            content_area.height -| self.padding_y * 2,
        );

        // Render text
        if (self.lines.len > 0) {
            var y = text_area.y;
            for (self.lines) |line| {
                if (y >= text_area.y + text_area.height) break;
                _ = buf.setString(text_area.x, y, line, self.style);
                y += 1;
            }
        } else {
            _ = buf.setString(text_area.x, text_area.y, self.text, self.style);
        }
    }

    fn fillBackground(self: Tooltip, area: Rect, buf: *Buffer) void {
        var y = area.top();
        while (y < area.bottom()) : (y += 1) {
            var x = area.left();
            while (x < area.right()) : (x += 1) {
                if (buf.getCell(x, y)) |cell| {
                    cell.setChar(' ');
                    cell.setStyle(self.style);
                }
            }
        }
    }
};

// ============================================================================
// TooltipManager
// ============================================================================

/// Manages tooltip display with timing/delay.
pub const TooltipManager = struct {
    /// Current tooltip.
    tooltip: Tooltip,

    /// Hover start time (milliseconds).
    hover_start_ms: i64 = 0,

    /// Delay before showing tooltip (ms).
    show_delay_ms: u32 = 500,

    /// How long to show tooltip (0 = until mouse moves).
    display_duration_ms: u32 = 0,

    /// Current hover position.
    hover_x: u16 = 0,
    hover_y: u16 = 0,

    /// Whether we're waiting to show.
    pending: bool = false,

    /// Creates a new tooltip manager.
    pub fn init() TooltipManager {
        return .{
            .tooltip = Tooltip.init(""),
        };
    }

    /// Sets the show delay.
    pub fn setDelay(self: *TooltipManager, delay_ms: u32) void {
        self.show_delay_ms = delay_ms;
    }

    /// Called when mouse moves to a position with a tooltip.
    pub fn onHover(self: *TooltipManager, x: u16, y: u16, text: []const u8, current_time_ms: i64) void {
        if (self.hover_x != x or self.hover_y != y) {
            // Position changed, reset timer
            self.hover_x = x;
            self.hover_y = y;
            self.hover_start_ms = current_time_ms;
            self.pending = true;
            self.tooltip.hide();
            self.tooltip.text = text;
        }
    }

    /// Called when mouse leaves tooltip area.
    pub fn onLeave(self: *TooltipManager) void {
        self.pending = false;
        self.tooltip.hide();
    }

    /// Updates the tooltip state, should be called each frame.
    pub fn update(self: *TooltipManager, current_time_ms: i64, bounds: Rect) void {
        if (self.pending) {
            const elapsed = current_time_ms - self.hover_start_ms;
            if (elapsed >= self.show_delay_ms) {
                self.tooltip.showNear(self.hover_x, self.hover_y, bounds);
                self.pending = false;
            }
        }
    }

    /// Renders the tooltip if visible.
    pub fn render(self: TooltipManager, bounds: Rect, buf: *Buffer) void {
        self.tooltip.render(bounds, buf);
    }

    /// Returns whether tooltip is visible.
    pub fn isVisible(self: TooltipManager) bool {
        return self.tooltip.isVisible();
    }
};

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

test "Tooltip basic" {
    var tooltip = Tooltip.init("Hello, World!");

    try std.testing.expect(!tooltip.isVisible());
    try std.testing.expectEqualStrings("Hello, World!", tooltip.text);

    tooltip.showAt(10, 5);
    try std.testing.expect(tooltip.isVisible());
    try std.testing.expectEqual(@as(u16, 10), tooltip.x);
    try std.testing.expectEqual(@as(u16, 5), tooltip.y);

    tooltip.hide();
    try std.testing.expect(!tooltip.isVisible());
}

test "Tooltip size calculation" {
    const tooltip = Tooltip.init("Test").setBorder(true);
    const size = tooltip.calculateSize();

    // "Test" = 4 chars + 2 padding + 2 border = 8
    try std.testing.expectEqual(@as(u16, 8), size.width);
    // 1 line + 0 padding + 2 border = 3
    try std.testing.expectEqual(@as(u16, 3), size.height);
}

test "Tooltip multiline" {
    const tooltip = Tooltip.initMultiline(&.{
        "Line 1",
        "Longer line 2",
        "L3",
    }).setBorder(false);

    const size = tooltip.calculateSize();

    // "Longer line 2" = 13 chars + 2 padding = 15
    try std.testing.expectEqual(@as(u16, 15), size.width);
    // 3 lines
    try std.testing.expectEqual(@as(u16, 3), size.height);
}

test "Tooltip showNear auto position" {
    var tooltip = Tooltip.init("Tip").setPosition(.auto);
    const bounds = Rect.init(0, 0, 80, 24);

    // Near top - should go below
    tooltip.showNear(10, 2, bounds);
    try std.testing.expect(tooltip.y > 2);

    // Near bottom - should go above
    tooltip.showNear(10, 22, bounds);
    try std.testing.expect(tooltip.y < 22);
}

test "TooltipManager delay" {
    var manager = TooltipManager.init();
    manager.setDelay(100);

    const bounds = Rect.init(0, 0, 80, 24);

    // Start hover
    manager.onHover(10, 10, "Test", 0);
    try std.testing.expect(!manager.isVisible());
    try std.testing.expect(manager.pending);

    // Not enough time
    manager.update(50, bounds);
    try std.testing.expect(!manager.isVisible());

    // Enough time
    manager.update(100, bounds);
    try std.testing.expect(manager.isVisible());

    // Leave
    manager.onLeave();
    try std.testing.expect(!manager.isVisible());
}