    /// Deflate is a lossless data compression file format that uses a combination
    /// of LZ77 and Huffman coding.
    pub const deflate = @import("flate/deflate.zig");

    /// Inflate is the decoding process that takes a Deflate bitstream for
    /// decompression and correctly produces the original full-size data or file.
    pub const inflate = @import("flate/inflate.zig");

    /// Decompress compressed data from reader and write plain data to the writer.
    pub fn decompress(reader: anytype, writer: anytype) !void {
        try inflate.decompress(.raw, reader, writer);
    }

    /// Decompressor type
    pub fn Decompressor(comptime ReaderType: type) type {
        return inflate.Decompressor(.raw, ReaderType);
    }

    /// Create Decompressor which will read compressed data from reader.
    pub fn decompressor(reader: anytype) Decompressor(@TypeOf(reader)) {
        return inflate.decompressor(.raw, reader);
    }

    /// Compression level, trades between speed and compression size.
    pub const Options = deflate.Options;

    /// Compress plain data from reader and write compressed data to the writer.
    pub fn compress(reader: anytype, writer: anytype, options: Options) !void {
        try deflate.compress(.raw, reader, writer, options);
    }

    /// Compressor type
    pub fn Compressor(comptime WriterType: type) type {
        return deflate.Compressor(.raw, WriterType);
    }

    /// Create Compressor which outputs compressed data to the writer.
    pub fn compressor(writer: anytype, options: Options) !Compressor(@TypeOf(writer)) {
        return try deflate.compressor(.raw, writer, options);
    }

    /// Huffman only compression. Without Lempel-Ziv match searching. Faster
    /// compression, less memory requirements but bigger compressed sizes.
    pub const huffman = struct {
        pub fn compress(reader: anytype, writer: anytype) !void {
            try deflate.huffman.compress(.raw, reader, writer);
        }

        pub fn Compressor(comptime WriterType: type) type {
            return deflate.huffman.Compressor(.raw, WriterType);
        }

        pub fn compressor(writer: anytype) !huffman.Compressor(@TypeOf(writer)) {
            return deflate.huffman.compressor(.raw, writer);
        }
    };

    // No compression store only. Compressed size is slightly bigger than plain.

    pub const store = struct {
        pub fn compress(reader: anytype, writer: anytype) !void {
            try deflate.store.compress(.raw, reader, writer);
        }

        pub fn Compressor(comptime WriterType: type) type {
            return deflate.store.Compressor(.raw, WriterType);
        }

        pub fn compressor(writer: anytype) !store.Compressor(@TypeOf(writer)) {
            return deflate.store.compressor(.raw, writer);
        }
    };

    /// Container defines header/footer arround deflate bit stream. Gzip and zlib
    /// compression algorithms are containers arround deflate bit stream body.
    const Container = @import("flate/container.zig").Container;
    const std = @import("std");
    const testing = std.testing;
    const fixedBufferStream = std.io.fixedBufferStream;
    const print = std.debug.print;
    const builtin = @import("builtin");

    test {
        _ = deflate;
        _ = inflate;
    }

    test "compress/decompress" {
        var cmp_buf: [64 * 1024]u8 = undefined; // compressed data buffer

        var dcm_buf: [64 * 1024]u8 = undefined; // decompressed data buffer

        const levels = [_]deflate.Level{ .level_4, .level_5, .level_6, .level_7, .level_8, .level_9 };
        const cases = [_]struct {
            data: []const u8, // uncompressed content

            // compressed data sizes per level 4-9

            gzip_sizes: [levels.len]usize = [_]usize{0} ** levels.len,
            huffman_only_size: usize = 0,
            store_size: usize = 0,
        }{
            .{
                .data = @embedFile("flate/testdata/rfc1951.txt"),
                .gzip_sizes = [_]usize{ 11513, 11217, 11139, 11126, 11122, 11119 },
                .huffman_only_size = 20287,
                .store_size = 36967,
            },
            .{
                .data = @embedFile("flate/testdata/fuzz/roundtrip1.input"),
                .gzip_sizes = [_]usize{ 373, 370, 370, 370, 370, 370 },
                .huffman_only_size = 393,
                .store_size = 393,
            },
            .{
                .data = @embedFile("flate/testdata/fuzz/roundtrip2.input"),
                .gzip_sizes = [_]usize{ 373, 373, 373, 373, 373, 373 },
                .huffman_only_size = 394,
                .store_size = 394,
            },
            .{
                .data = @embedFile("flate/testdata/fuzz/deflate-stream.expect"),
                .gzip_sizes = [_]usize{ 351, 347, 347, 347, 347, 347 },
                .huffman_only_size = 498,
                .store_size = 747,
            },
        };

        for (cases, 0..) |case, case_no| { // for each case

            const data = case.data;

            for (levels, 0..) |level, i| { // for each compression level

                inline for (Container.list) |container| { // for each wrapping

                    var compressed_size: usize = if (case.gzip_sizes[i] > 0)
                        case.gzip_sizes[i] - Container.gzip.size() + container.size()
                    else
                        0;

                    // compress original stream to compressed stream

                    {
                        var original = fixedBufferStream(data);
                        var compressed = fixedBufferStream(&cmp_buf);
                        try deflate.compress(container, original.reader(), compressed.writer(), .{ .level = level });
                        if (compressed_size == 0) {
                            if (container == .gzip)
                                print("case {d} gzip level {} compressed size: {d}\n", .{ case_no, level, compressed.pos });
                            compressed_size = compressed.pos;
                        }
                        try testing.expectEqual(compressed_size, compressed.pos);
                    }
                    // decompress compressed stream to decompressed stream

                    {
                        var compressed = fixedBufferStream(cmp_buf[0..compressed_size]);
                        var decompressed = fixedBufferStream(&dcm_buf);
                        try inflate.decompress(container, compressed.reader(), decompressed.writer());
                        try testing.expectEqualSlices(u8, data, decompressed.getWritten());
                    }

                    // compressor writer interface

                    {
                        var compressed = fixedBufferStream(&cmp_buf);
                        var cmp = try deflate.compressor(container, compressed.writer(), .{ .level = level });
                        var cmp_wrt = cmp.writer();
                        try cmp_wrt.writeAll(data);
                        try cmp.finish();

                        try testing.expectEqual(compressed_size, compressed.pos);
                    }
                    // decompressor reader interface

                    {
                        var compressed = fixedBufferStream(cmp_buf[0..compressed_size]);
                        var dcm = inflate.decompressor(container, compressed.reader());
                        var dcm_rdr = dcm.reader();
                        const n = try dcm_rdr.readAll(&dcm_buf);
                        try testing.expectEqual(data.len, n);
                        try testing.expectEqualSlices(u8, data, dcm_buf[0..n]);
                    }
                }
            }
            // huffman only compression

            {
                inline for (Container.list) |container| { // for each wrapping

                    var compressed_size: usize = if (case.huffman_only_size > 0)
                        case.huffman_only_size - Container.gzip.size() + container.size()
                    else
                        0;

                    // compress original stream to compressed stream

                    {
                        var original = fixedBufferStream(data);
                        var compressed = fixedBufferStream(&cmp_buf);
                        var cmp = try deflate.huffman.compressor(container, compressed.writer());
                        try cmp.compress(original.reader());
                        try cmp.finish();
                        if (compressed_size == 0) {
                            if (container == .gzip)
                                print("case {d} huffman only compressed size: {d}\n", .{ case_no, compressed.pos });
                            compressed_size = compressed.pos;
                        }
                        try testing.expectEqual(compressed_size, compressed.pos);
                    }
                    // decompress compressed stream to decompressed stream

                    {
                        var compressed = fixedBufferStream(cmp_buf[0..compressed_size]);
                        var decompressed = fixedBufferStream(&dcm_buf);
                        try inflate.decompress(container, compressed.reader(), decompressed.writer());
                        try testing.expectEqualSlices(u8, data, decompressed.getWritten());
                    }
                }
            }

            // store only

            {
                inline for (Container.list) |container| { // for each wrapping

                    var compressed_size: usize = if (case.store_size > 0)
                        case.store_size - Container.gzip.size() + container.size()
                    else
                        0;

                    // compress original stream to compressed stream

                    {
                        var original = fixedBufferStream(data);
                        var compressed = fixedBufferStream(&cmp_buf);
                        var cmp = try deflate.store.compressor(container, compressed.writer());
                        try cmp.compress(original.reader());
                        try cmp.finish();
                        if (compressed_size == 0) {
                            if (container == .gzip)
                                print("case {d} store only compressed size: {d}\n", .{ case_no, compressed.pos });
                            compressed_size = compressed.pos;
                        }

                        try testing.expectEqual(compressed_size, compressed.pos);
                    }
                    // decompress compressed stream to decompressed stream

                    {
                        var compressed = fixedBufferStream(cmp_buf[0..compressed_size]);
                        var decompressed = fixedBufferStream(&dcm_buf);
                        try inflate.decompress(container, compressed.reader(), decompressed.writer());
                        try testing.expectEqualSlices(u8, data, decompressed.getWritten());
                    }
                }
            }
        }
    }

    fn testDecompress(comptime container: Container, compressed: []const u8, expected_plain: []const u8) !void {
        var in = fixedBufferStream(compressed);
        var out = std.ArrayList(u8).init(testing.allocator);
        defer out.deinit();

        try inflate.decompress(container, in.reader(), out.writer());
        try testing.expectEqualSlices(u8, expected_plain, out.items);
    }

    test "don't read past deflate stream's end" {
        try testDecompress(.zlib, &[_]u8{
            0x08, 0xd7, 0x63, 0xf8, 0xcf, 0xc0, 0xc0, 0x00, 0xc1, 0xff,
            0xff, 0x43, 0x30, 0x03, 0x03, 0xc3, 0xff, 0xff, 0xff, 0x01,
            0x83, 0x95, 0x0b, 0xf5,
        }, &[_]u8{
            0x00, 0xff, 0x00, 0x00, 0x00, 0xff, 0x00, 0x00, 0x00, 0xff,
            0x00, 0xff, 0xff, 0xff, 0x00, 0xff, 0xff, 0xff, 0x00, 0x00,
            0x00, 0x00, 0xff, 0xff, 0xff,
        });
    }

    test "zlib header" {
        // Truncated header

        try testing.expectError(
            error.EndOfStream,
            testDecompress(.zlib, &[_]u8{0x78}, ""),
        );
        // Wrong CM

        try testing.expectError(
            error.BadZlibHeader,
            testDecompress(.zlib, &[_]u8{ 0x79, 0x94 }, ""),
        );
        // Wrong CINFO

        try testing.expectError(
            error.BadZlibHeader,
            testDecompress(.zlib, &[_]u8{ 0x88, 0x98 }, ""),
        );
        // Wrong checksum

        try testing.expectError(
            error.WrongZlibChecksum,
            testDecompress(.zlib, &[_]u8{ 0x78, 0xda, 0x03, 0x00, 0x00, 0x00, 0x00, 0x00 }, ""),
        );
        // Truncated checksum

        try testing.expectError(
            error.EndOfStream,
            testDecompress(.zlib, &[_]u8{ 0x78, 0xda, 0x03, 0x00, 0x00 }, ""),
        );
    }

    test "gzip header" {
        // Truncated header

        try testing.expectError(
            error.EndOfStream,
            testDecompress(.gzip, &[_]u8{ 0x1f, 0x8B }, undefined),
        );
        // Wrong CM

        try testing.expectError(
            error.BadGzipHeader,
            testDecompress(.gzip, &[_]u8{
                0x1f, 0x8b, 0x09, 0x00, 0x00, 0x00, 0x00, 0x00,
                0x00, 0x03,
            }, undefined),
        );

        // Wrong checksum

        try testing.expectError(
            error.WrongGzipChecksum,
            testDecompress(.gzip, &[_]u8{
                0x1f, 0x8b, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00,
                0x00, 0x03, 0x03, 0x00, 0x00, 0x00, 0x00, 0x01,
                0x00, 0x00, 0x00, 0x00,
            }, undefined),
        );
        // Truncated checksum

        try testing.expectError(
            error.EndOfStream,
            testDecompress(.gzip, &[_]u8{
                0x1f, 0x8b, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00,
                0x00, 0x03, 0x03, 0x00, 0x00, 0x00, 0x00,
            }, undefined),
        );
        // Wrong initial size

        try testing.expectError(
            error.WrongGzipSize,
            testDecompress(.gzip, &[_]u8{
                0x1f, 0x8b, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00,
                0x00, 0x03, 0x03, 0x00, 0x00, 0x00, 0x00, 0x00,
                0x00, 0x00, 0x00, 0x01,
            }, undefined),
        );
        // Truncated initial size field

        try testing.expectError(
            error.EndOfStream,
            testDecompress(.gzip, &[_]u8{
                0x1f, 0x8b, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00,
                0x00, 0x03, 0x03, 0x00, 0x00, 0x00, 0x00, 0x00,
                0x00, 0x00, 0x00,
            }, undefined),
        );

        try testDecompress(.gzip, &[_]u8{
            // GZIP header

            0x1f, 0x8b, 0x08, 0x12, 0x00, 0x09, 0x6e, 0x88, 0x00, 0xff, 0x48, 0x65, 0x6c, 0x6c, 0x6f, 0x00,
            // header.FHCRC (should cover entire header)

            0x99, 0xd6,
            // GZIP data

            0x01, 0x00, 0x00, 0xff, 0xff, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        }, "");
    }

    test "public interface" {
        const plain_data = [_]u8{ 'H', 'e', 'l', 'l', 'o', ' ', 'w', 'o', 'r', 'l', 'd', 0x0a };

        // deflate final stored block, header + plain (stored) data

        const deflate_block = [_]u8{
            0b0000_0001, 0b0000_1100, 0x00, 0b1111_0011, 0xff, // deflate fixed buffer header len, nlen

        } ++ plain_data;

        // gzip header/footer + deflate block

        const gzip_data =
            [_]u8{ 0x1f, 0x8b, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x03 } ++ // gzip header (10 bytes)

            deflate_block ++
            [_]u8{ 0xd5, 0xe0, 0x39, 0xb7, 0x0c, 0x00, 0x00, 0x00 }; // gzip footer checksum (4 byte), size (4 bytes)

        // zlib header/footer + deflate block

        const zlib_data = [_]u8{ 0x78, 0b10_0_11100 } ++ // zlib header (2 bytes)}

            deflate_block ++
            [_]u8{ 0x1c, 0xf2, 0x04, 0x47 }; // zlib footer: checksum

        const gzip = @import("gzip.zig");
        const zlib = @import("zlib.zig");
        const flate = @This();

        try testInterface(gzip, &gzip_data, &plain_data);
        try testInterface(zlib, &zlib_data, &plain_data);
        try testInterface(flate, &deflate_block, &plain_data);
    }

    fn testInterface(comptime pkg: type, gzip_data: []const u8, plain_data: []const u8) !void {
        var buffer1: [64]u8 = undefined;
        var buffer2: [64]u8 = undefined;

        var compressed = fixedBufferStream(&buffer1);
        var plain = fixedBufferStream(&buffer2);

        // decompress

        {
            var in = fixedBufferStream(gzip_data);
            try pkg.decompress(in.reader(), plain.writer());
            try testing.expectEqualSlices(u8, plain_data, plain.getWritten());
        }
        plain.reset();
        compressed.reset();

        // compress/decompress

        {
            var in = fixedBufferStream(plain_data);
            try pkg.compress(in.reader(), compressed.writer(), .{});
            compressed.reset();
            try pkg.decompress(compressed.reader(), plain.writer());
            try testing.expectEqualSlices(u8, plain_data, plain.getWritten());
        }
        plain.reset();
        compressed.reset();

        // compressor/decompressor

        {
            var in = fixedBufferStream(plain_data);
            var cmp = try pkg.compressor(compressed.writer(), .{});
            try cmp.compress(in.reader());
            try cmp.finish();

            compressed.reset();
            var dcp = pkg.decompressor(compressed.reader());
            try dcp.decompress(plain.writer());
            try testing.expectEqualSlices(u8, plain_data, plain.getWritten());
        }
        plain.reset();
        compressed.reset();

        // huffman

        {
            // huffman compress/decompress

            {
                var in = fixedBufferStream(plain_data);
                try pkg.huffman.compress(in.reader(), compressed.writer());
                compressed.reset();
                try pkg.decompress(compressed.reader(), plain.writer());
                try testing.expectEqualSlices(u8, plain_data, plain.getWritten());
            }
            plain.reset();
            compressed.reset();

            // huffman compressor/decompressor

            {
                var in = fixedBufferStream(plain_data);
                var cmp = try pkg.huffman.compressor(compressed.writer());
                try cmp.compress(in.reader());
                try cmp.finish();

                compressed.reset();
                try pkg.decompress(compressed.reader(), plain.writer());
                try testing.expectEqualSlices(u8, plain_data, plain.getWritten());
            }
        }
        plain.reset();
        compressed.reset();

        // store

        {
            // store compress/decompress

            {
                var in = fixedBufferStream(plain_data);
                try pkg.store.compress(in.reader(), compressed.writer());
                compressed.reset();
                try pkg.decompress(compressed.reader(), plain.writer());
                try testing.expectEqualSlices(u8, plain_data, plain.getWritten());
            }
            plain.reset();
            compressed.reset();

            // store compressor/decompressor

            {
                var in = fixedBufferStream(plain_data);
                var cmp = try pkg.store.compressor(compressed.writer());
                try cmp.compress(in.reader());
                try cmp.finish();

                compressed.reset();
                try pkg.decompress(compressed.reader(), plain.writer());
                try testing.expectEqualSlices(u8, plain_data, plain.getWritten());
            }
        }
    }