const std = @import("std");
const expect = std.testing.expect;

const JavascriptString = @import("ast/base.zig").JavascriptString;

usingnamespace @import("string_types.zig");

pub fn containsChar(self: string, char: u8) bool {
    return std.mem(char) != null;
}

pub fn indexOfChar(self: string, char: u8) ?usize {
    return std.mem.indexOfScalar(@TypeOf(char), self, char);
}

pub fn lastIndexOfChar(self: string, char: u8) ?usize {
    return std.mem.lastIndexOfScalar(u8, self, char);
}

pub fn lastIndexOf(self: string, str: u8) ?usize {
    return std.mem.lastIndexOf(u8, self, str);
}

pub fn indexOf(self: string, str: u8) ?usize {
    return std.mem.indexOf(u8, self, str);
}

pub fn startsWith(self: string, str: string) bool {
    if (str.len > self.len) {
        return false;
    }

    var i: usize = 0;
    while (i < str.len) {
        if (str[i] != self[i]) {
            return false;
        }
        i += 1;
    }

    return true;
}

pub fn endsWithAny(self: string, str: string) bool {
    const end = self[self.len - 1];
    for (str) |char| {
        if (char == end) {
            return true;
        }
    }

    return false;
}

pub fn lastNonwhitespace(self: string, str: string) bool {}

pub fn endsWithAnyComptime(self: string, comptime str: string) bool {
    if (str.len < 10) {
        const last = self[self.len - 1];
        inline while (str) |char| {
            if (char == last) {
                return true;
            }
        }

        return false;
    } else {
        return endsWithAny(self, str);
    }
}

pub fn eql(self: string, other: anytype) bool {
    return std.mem.eql(u8, self, other);
}

pub fn append(allocator: *std.mem.Allocator, self: string, other: string) !string {
    return std.fmt.allocPrint(allocator, "{s}{s}", .{ self, other });
}

pub fn index(self: string, str: string) i32 {
    if (std.mem.indexOf(u8, self, str)) |i| {
        return @intCast(i32, i);
    } else {
        return -1;
    }
}

pub fn eqlUtf16(comptime self: string, other: JavascriptString) bool {
    return std.mem.eql(u16, std.unicode.utf8ToUtf16LeStringLiteral(self), other);
}

pub fn toUTF16Buf(in: string, out: []u16) usize {
    var utf8Iterator = std.unicode.Utf8Iterator{ .bytes = in, .i = 0 };

    var c: u21 = 0;
    var i: usize = 0;
    while (utf8Iterator.nextCodepoint()) |code_point| {
        switch (code_point) {
            0...0xFFFF => {
                out[i] = @intCast(u16, code_point);
                i += 1;
            },
            else => {
                c = code_point - 0x10000;
                out[i] = @intCast(u16, 0xD800 + ((c >> 10) & 0x3FF));
                i += 1;
                out[i] = @intCast(u16, 0xDC00 + (c & 0x3FF));
                i += 1;
            },
        }
    }

    return utf8Iterator.i;
}

pub fn toUTF16Alloc(in: string, allocator: *std.mem.Allocator) !JavascriptString {
    var utf8Iterator = std.unicode.Utf8Iterator{ .bytes = in, .i = 0 };
    var out = try std.ArrayList(u16).initCapacity(allocator, in.len);

    var c: u21 = 0;
    var i: usize = 0;
    while (utf8Iterator.nextCodepoint()) |code_point| {
        switch (code_point) {
            0...0xFFFF => {
                try out.append(@intCast(u16, code_point));
            },
            else => {
                c = code_point - 0x10000;
                try out.append(@intCast(u16, 0xD800 + ((c >> 10) & 0x3FF)));
                try out.append(@intCast(u16, 0xDC00 + (c & 0x3FF)));
            },
        }
    }

    return out.toOwnedSlice();
}

pub fn containsNonBmpCodePoint(text: string) bool {
    var iter = std.unicode.Utf8Iterator{ .bytes = text, .i = 0 };

    while (iter.nextCodepoint()) |codepoint| {
        if (codepoint > 0xFFFF) {
            return true;
        }
    }

    return false;
}

pub fn containsNonBmpCodePointUTF16(_text: JavascriptString) bool {
    const n = _text.len;
    if (n > 0) {
        var i: usize = 0;
        var c: u16 = 0;
        var c2: u16 = 0;
        var text = _text[0 .. n - 1];
        while (i < n - 1) : (i += 1) {
            c = text[i];
            if (c >= 0xD800 and c <= 0xDBFF) {
                c2 = text[i + 1];
                if (c2 >= 0xDC00 and c2 <= 0xDFFF) {
                    return true;
                }
            }
        }
    }

    return false;
}