//! Line drawing characters.
//!
//! Provides sets of Unicode box-drawing characters for creating lines,
//! borders, and tables with various styles (normal, rounded, double, thick).

const std = @import("std");

// ============================================================================
// Individual Line Characters
// ============================================================================

// Vertical lines
pub const VERTICAL: []const u8 = "│";
pub const DOUBLE_VERTICAL: []const u8 = "║";
pub const THICK_VERTICAL: []const u8 = "┃";
pub const LIGHT_DOUBLE_DASH_VERTICAL: []const u8 = "╎";
pub const HEAVY_DOUBLE_DASH_VERTICAL: []const u8 = "╏";
pub const LIGHT_TRIPLE_DASH_VERTICAL: []const u8 = "┆";
pub const HEAVY_TRIPLE_DASH_VERTICAL: []const u8 = "┇";
pub const LIGHT_QUADRUPLE_DASH_VERTICAL: []const u8 = "┊";
pub const HEAVY_QUADRUPLE_DASH_VERTICAL: []const u8 = "┋";

// Horizontal lines
pub const HORIZONTAL: []const u8 = "─";
pub const DOUBLE_HORIZONTAL: []const u8 = "═";
pub const THICK_HORIZONTAL: []const u8 = "━";
pub const LIGHT_DOUBLE_DASH_HORIZONTAL: []const u8 = "╌";
pub const HEAVY_DOUBLE_DASH_HORIZONTAL: []const u8 = "╍";
pub const LIGHT_TRIPLE_DASH_HORIZONTAL: []const u8 = "┄";
pub const HEAVY_TRIPLE_DASH_HORIZONTAL: []const u8 = "┅";
pub const LIGHT_QUADRUPLE_DASH_HORIZONTAL: []const u8 = "┈";
pub const HEAVY_QUADRUPLE_DASH_HORIZONTAL: []const u8 = "┉";

// Corners - Top Right
pub const TOP_RIGHT: []const u8 = "┐";
pub const ROUNDED_TOP_RIGHT: []const u8 = "╮";
pub const DOUBLE_TOP_RIGHT: []const u8 = "╗";
pub const THICK_TOP_RIGHT: []const u8 = "┓";

// Corners - Top Left
pub const TOP_LEFT: []const u8 = "┌";
pub const ROUNDED_TOP_LEFT: []const u8 = "╭";
pub const DOUBLE_TOP_LEFT: []const u8 = "╔";
pub const THICK_TOP_LEFT: []const u8 = "┏";

// Corners - Bottom Right
pub const BOTTOM_RIGHT: []const u8 = "┘";
pub const ROUNDED_BOTTOM_RIGHT: []const u8 = "╯";
pub const DOUBLE_BOTTOM_RIGHT: []const u8 = "╝";
pub const THICK_BOTTOM_RIGHT: []const u8 = "┛";

// Corners - Bottom Left
pub const BOTTOM_LEFT: []const u8 = "└";
pub const ROUNDED_BOTTOM_LEFT: []const u8 = "╰";
pub const DOUBLE_BOTTOM_LEFT: []const u8 = "╚";
pub const THICK_BOTTOM_LEFT: []const u8 = "┗";

// T-junctions
pub const VERTICAL_LEFT: []const u8 = "┤";
pub const DOUBLE_VERTICAL_LEFT: []const u8 = "╣";
pub const THICK_VERTICAL_LEFT: []const u8 = "┫";

pub const VERTICAL_RIGHT: []const u8 = "├";
pub const DOUBLE_VERTICAL_RIGHT: []const u8 = "╠";
pub const THICK_VERTICAL_RIGHT: []const u8 = "┣";

pub const HORIZONTAL_DOWN: []const u8 = "┬";
pub const DOUBLE_HORIZONTAL_DOWN: []const u8 = "╦";
pub const THICK_HORIZONTAL_DOWN: []const u8 = "┳";

pub const HORIZONTAL_UP: []const u8 = "┴";
pub const DOUBLE_HORIZONTAL_UP: []const u8 = "╩";
pub const THICK_HORIZONTAL_UP: []const u8 = "┻";

// Cross
pub const CROSS: []const u8 = "┼";
pub const DOUBLE_CROSS: []const u8 = "╬";
pub const THICK_CROSS: []const u8 = "╋";

// ============================================================================
// Line Set
// ============================================================================

/// A complete set of line drawing characters for a particular style.
pub const Set = struct {
    vertical: []const u8,
    horizontal: []const u8,
    top_right: []const u8,
    top_left: []const u8,
    bottom_right: []const u8,
    bottom_left: []const u8,
    vertical_left: []const u8,
    vertical_right: []const u8,
    horizontal_down: []const u8,
    horizontal_up: []const u8,
    cross: []const u8,

    pub const default: Set = NORMAL;
};

/// Normal (thin) line set.
/// ```
/// ┌─┬┐
/// │ ││
/// ├─┼┤
/// └─┴┘
/// ```
pub const NORMAL: Set = .{
    .vertical = VERTICAL,
    .horizontal = HORIZONTAL,
    .top_right = TOP_RIGHT,
    .top_left = TOP_LEFT,
    .bottom_right = BOTTOM_RIGHT,
    .bottom_left = BOTTOM_LEFT,
    .vertical_left = VERTICAL_LEFT,
    .vertical_right = VERTICAL_RIGHT,
    .horizontal_down = HORIZONTAL_DOWN,
    .horizontal_up = HORIZONTAL_UP,
    .cross = CROSS,
};

/// Rounded corner line set.
/// ```
/// ╭─┬╮
/// │ ││
/// ├─┼┤
/// ╰─┴╯
/// ```
pub const ROUNDED: Set = .{
    .vertical = VERTICAL,
    .horizontal = HORIZONTAL,
    .top_right = ROUNDED_TOP_RIGHT,
    .top_left = ROUNDED_TOP_LEFT,
    .bottom_right = ROUNDED_BOTTOM_RIGHT,
    .bottom_left = ROUNDED_BOTTOM_LEFT,
    .vertical_left = VERTICAL_LEFT,
    .vertical_right = VERTICAL_RIGHT,
    .horizontal_down = HORIZONTAL_DOWN,
    .horizontal_up = HORIZONTAL_UP,
    .cross = CROSS,
};

/// Double line set.
/// ```
/// ╔═╦╗
/// ║ ║║
/// ╠═╬╣
/// ╚═╩╝
/// ```
pub const DOUBLE: Set = .{
    .vertical = DOUBLE_VERTICAL,
    .horizontal = DOUBLE_HORIZONTAL,
    .top_right = DOUBLE_TOP_RIGHT,
    .top_left = DOUBLE_TOP_LEFT,
    .bottom_right = DOUBLE_BOTTOM_RIGHT,
    .bottom_left = DOUBLE_BOTTOM_LEFT,
    .vertical_left = DOUBLE_VERTICAL_LEFT,
    .vertical_right = DOUBLE_VERTICAL_RIGHT,
    .horizontal_down = DOUBLE_HORIZONTAL_DOWN,
    .horizontal_up = DOUBLE_HORIZONTAL_UP,
    .cross = DOUBLE_CROSS,
};

/// Thick (heavy) line set.
/// ```
/// ┏━┳┓
/// ┃ ┃┃
/// ┣━╋┫
/// ┗━┻┛
/// ```
pub const THICK: Set = .{
    .vertical = THICK_VERTICAL,
    .horizontal = THICK_HORIZONTAL,
    .top_right = THICK_TOP_RIGHT,
    .top_left = THICK_TOP_LEFT,
    .bottom_right = THICK_BOTTOM_RIGHT,
    .bottom_left = THICK_BOTTOM_LEFT,
    .vertical_left = THICK_VERTICAL_LEFT,
    .vertical_right = THICK_VERTICAL_RIGHT,
    .horizontal_down = THICK_HORIZONTAL_DOWN,
    .horizontal_up = THICK_HORIZONTAL_UP,
    .cross = THICK_CROSS,
};

/// Light double-dashed line set.
pub const LIGHT_DOUBLE_DASHED: Set = .{
    .vertical = LIGHT_DOUBLE_DASH_VERTICAL,
    .horizontal = LIGHT_DOUBLE_DASH_HORIZONTAL,
    .top_right = TOP_RIGHT,
    .top_left = TOP_LEFT,
    .bottom_right = BOTTOM_RIGHT,
    .bottom_left = BOTTOM_LEFT,
    .vertical_left = VERTICAL_LEFT,
    .vertical_right = VERTICAL_RIGHT,
    .horizontal_down = HORIZONTAL_DOWN,
    .horizontal_up = HORIZONTAL_UP,
    .cross = CROSS,
};

/// Heavy double-dashed line set.
pub const HEAVY_DOUBLE_DASHED: Set = .{
    .vertical = HEAVY_DOUBLE_DASH_VERTICAL,
    .horizontal = HEAVY_DOUBLE_DASH_HORIZONTAL,
    .top_right = THICK_TOP_RIGHT,
    .top_left = THICK_TOP_LEFT,
    .bottom_right = THICK_BOTTOM_RIGHT,
    .bottom_left = THICK_BOTTOM_LEFT,
    .vertical_left = THICK_VERTICAL_LEFT,
    .vertical_right = THICK_VERTICAL_RIGHT,
    .horizontal_down = THICK_HORIZONTAL_DOWN,
    .horizontal_up = THICK_HORIZONTAL_UP,
    .cross = THICK_CROSS,
};

/// Light triple-dashed line set.
pub const LIGHT_TRIPLE_DASHED: Set = .{
    .vertical = LIGHT_TRIPLE_DASH_VERTICAL,
    .horizontal = LIGHT_TRIPLE_DASH_HORIZONTAL,
    .top_right = TOP_RIGHT,
    .top_left = TOP_LEFT,
    .bottom_right = BOTTOM_RIGHT,
    .bottom_left = BOTTOM_LEFT,
    .vertical_left = VERTICAL_LEFT,
    .vertical_right = VERTICAL_RIGHT,
    .horizontal_down = HORIZONTAL_DOWN,
    .horizontal_up = HORIZONTAL_UP,
    .cross = CROSS,
};

/// Heavy triple-dashed line set.
pub const HEAVY_TRIPLE_DASHED: Set = .{
    .vertical = HEAVY_TRIPLE_DASH_VERTICAL,
    .horizontal = HEAVY_TRIPLE_DASH_HORIZONTAL,
    .top_right = THICK_TOP_RIGHT,
    .top_left = THICK_TOP_LEFT,
    .bottom_right = THICK_BOTTOM_RIGHT,
    .bottom_left = THICK_BOTTOM_LEFT,
    .vertical_left = THICK_VERTICAL_LEFT,
    .vertical_right = THICK_VERTICAL_RIGHT,
    .horizontal_down = THICK_HORIZONTAL_DOWN,
    .horizontal_up = THICK_HORIZONTAL_UP,
    .cross = THICK_CROSS,
};

/// Light quadruple-dashed line set.
pub const LIGHT_QUADRUPLE_DASHED: Set = .{
    .vertical = LIGHT_QUADRUPLE_DASH_VERTICAL,
    .horizontal = LIGHT_QUADRUPLE_DASH_HORIZONTAL,
    .top_right = TOP_RIGHT,
    .top_left = TOP_LEFT,
    .bottom_right = BOTTOM_RIGHT,
    .bottom_left = BOTTOM_LEFT,
    .vertical_left = VERTICAL_LEFT,
    .vertical_right = VERTICAL_RIGHT,
    .horizontal_down = HORIZONTAL_DOWN,
    .horizontal_up = HORIZONTAL_UP,
    .cross = CROSS,
};

/// Heavy quadruple-dashed line set.
pub const HEAVY_QUADRUPLE_DASHED: Set = .{
    .vertical = HEAVY_QUADRUPLE_DASH_VERTICAL,
    .horizontal = HEAVY_QUADRUPLE_DASH_HORIZONTAL,
    .top_right = THICK_TOP_RIGHT,
    .top_left = THICK_TOP_LEFT,
    .bottom_right = THICK_BOTTOM_RIGHT,
    .bottom_left = THICK_BOTTOM_LEFT,
    .vertical_left = THICK_VERTICAL_LEFT,
    .vertical_right = THICK_VERTICAL_RIGHT,
    .horizontal_down = THICK_HORIZONTAL_DOWN,
    .horizontal_up = THICK_HORIZONTAL_UP,
    .cross = THICK_CROSS,
};

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

test "line set default" {
    try std.testing.expectEqualStrings(VERTICAL, Set.default.vertical);
    try std.testing.expectEqualStrings(HORIZONTAL, Set.default.horizontal);
}

test "line characters are valid UTF-8" {
    // Verify all characters decode properly
    const v: [3]u8 = VERTICAL[0..3].*;
    const h: [3]u8 = HORIZONTAL[0..3].*;
    const tl: [3]u8 = TOP_LEFT[0..3].*;
    _ = std.unicode.utf8Decode(&v) catch unreachable;
    _ = std.unicode.utf8Decode(&h) catch unreachable;
    _ = std.unicode.utf8Decode(&tl) catch unreachable;
}