/*
 * Copyright 2019 Google LLC
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */

#include "include/core/SkColorPriv.h"
#include "include/private/SkColorData.h"
#include "src/core/SkVM.h"
#include "tests/Test.h"
#include "tools/Resources.h"
#include "tools/SkVMBuilders.h"

using Fmt = SrcoverBuilder_F32::Fmt;
const char* fmt_name(Fmt fmt) {
    switch (fmt) {
        case Fmt::A8:        return "A8";
        case Fmt::G8:        return "G8";
        case Fmt::RGBA_8888: return "RGBA_8888";
    }
    return "";
}

DEF_TEST(SkVM, r) {
    SkDynamicMemoryWStream buf;

    // Write all combinations of SrcoverBuilder_F32
    for (int s = 0; s < 3; s++)
    for (int d = 0; d < 3; d++) {
        auto srcFmt = (Fmt)s,
             dstFmt = (Fmt)d;
        SrcoverBuilder_F32 builder{srcFmt, dstFmt};
        skvm::Program program = builder.done();

        buf.writeText(fmt_name(srcFmt));
        buf.writeText(" over ");
        buf.writeText(fmt_name(dstFmt));
        buf.writeText("\n");
        builder.dump(&buf);
        buf.writeText("\n");
        program.dump(&buf);
        buf.writeText("\n");
    }

    // Write the I32 Srcovers also.
    {
        skvm::Program program = SrcoverBuilder_I32_Naive{}.done();
        buf.writeText("I32 (Naive) 8888 over 8888\n");
        program.dump(&buf);
        buf.writeText("\n");
    }
    {
        skvm::Program program = SrcoverBuilder_I32{}.done();
        buf.writeText("I32 8888 over 8888\n");
        program.dump(&buf);
        buf.writeText("\n");
    }
    {
        skvm::Program program = SrcoverBuilder_I32_SWAR{}.done();
        buf.writeText("I32 (SWAR) 8888 over 8888\n");
        program.dump(&buf);
        buf.writeText("\n");
    }

    sk_sp<SkData> blob = buf.detachAsData();
    {

        sk_sp<SkData> expected = GetResourceAsData("SkVMTest.expected");
        REPORTER_ASSERT(r, expected, "Couldn't load SkVMTest.expected.");
        if (expected) {
            if (blob->size() != expected->size()
                    || 0 != memcmp(blob->data(), expected->data(), blob->size())) {

                ERRORF(r, "SkVMTest expected\n%.*s\nbut got\n%.*s\n",
                       expected->size(), expected->data(),
                       blob->size(), blob->data());
            }

            SkFILEWStream out(GetResourcePath("SkVMTest.expected").c_str());
            if (out.isValid()) {
                out.write(blob->data(), blob->size());
            }
        }
    }

    auto test_8888 = [&](const skvm::Program& program) {
        uint32_t src[9];
        uint32_t dst[SK_ARRAY_COUNT(src)];

        for (int i = 0; i < (int)SK_ARRAY_COUNT(src); i++) {
            src[i] = 0xbb007733;
            dst[i] = 0xffaaccee;
        }

        SkPMColor expected = SkPMSrcOver(src[0], dst[0]);  // 0xff2dad73

        program.eval((int)SK_ARRAY_COUNT(src), src, dst);

        // dst is probably 0xff2dad72.
        for (auto got : dst) {
            auto want = expected;
            for (int i = 0; i < 4; i++) {
                uint8_t d = got  & 0xff,
                        w = want & 0xff;
                REPORTER_ASSERT(r, abs(d-w) < 2);
                got  >>= 8;
                want >>= 8;
            }
        }
    };

    test_8888(SrcoverBuilder_F32{Fmt::RGBA_8888, Fmt::RGBA_8888}.done());
    test_8888(SrcoverBuilder_I32_Naive{}.done());
    test_8888(SrcoverBuilder_I32{}.done());
    test_8888(SrcoverBuilder_I32_SWAR{}.done());

    {
        skvm::Program program = SrcoverBuilder_F32{Fmt::RGBA_8888, Fmt::G8}.done();

        uint32_t src[9];
        uint8_t  dst[SK_ARRAY_COUNT(src)];

        for (int i = 0; i < (int)SK_ARRAY_COUNT(src); i++) {
            src[i] = 0xbb007733;
            dst[i] = 0x42;
        }

        SkPMColor over = SkPMSrcOver(SkPackARGB32(0xbb, 0x33, 0x77, 0x00),
                                     0xff424242);

        uint8_t want = SkComputeLuminance(SkGetPackedR32(over),
                                          SkGetPackedG32(over),
                                          SkGetPackedB32(over));
        program.eval((int)SK_ARRAY_COUNT(src), src, dst);

        for (auto got : dst) {
            REPORTER_ASSERT(r, abs(got-want) < 3);
        }
    }

    {
        skvm::Program program = SrcoverBuilder_F32{Fmt::A8, Fmt::A8}.done();

        uint8_t src[256],
                dst[256];
        for (int i = 0; i < 256; i++) {
            src[i] = 255 - i;
            dst[i] = i;
        }

        program.eval(256, src, dst);

        for (int i = 0; i < 256; i++) {
            uint8_t want = SkGetPackedA32(SkPMSrcOver(SkPackARGB32(src[i], 0,0,0),
                                                      SkPackARGB32(     i, 0,0,0)));
            REPORTER_ASSERT(r, abs(dst[i]-want) < 2);
        }
    }
}

DEF_TEST(SkVM_LoopCounts, r) {
    // Make sure we cover all the exact N we want.

    int buf[64];
    for (int N = 0; N <= (int)SK_ARRAY_COUNT(buf); N++) {
        for (int i = 0; i < (int)SK_ARRAY_COUNT(buf); i++) {
            buf[i] = i;
        }

        // buf[i] += 1
        skvm::Builder b;
        b.store32(b.arg(0),
                  b.add(b.splat(1),
                        b.load32(b.arg(0))));

        skvm::Program program = b.done();
        program.eval(N, buf);

        for (int i = 0; i < N; i++) {
            REPORTER_ASSERT(r, buf[i] == i+1);
        }
        for (int i = N; i < (int)SK_ARRAY_COUNT(buf); i++) {
            REPORTER_ASSERT(r, buf[i] == i);
        }
    }
}


#if defined(SKVM_JIT)

template <typename Fn>
static void test_asm(skiatest::Reporter* r, Fn&& fn, std::initializer_list<uint8_t> expected) {
    skvm::Assembler a;
    fn(a);

    REPORTER_ASSERT(r, a.size() == expected.size());

    auto got = (const uint8_t*)a.code(),
         want = expected.begin();
    for (int i = 0; i < (int)std::min(a.size(), expected.size()); i++) {
        REPORTER_ASSERT(r, got[i] == want[i],
                        "byte %d was %02x, want %02x", i, got[i], want[i]);
    }
}

DEF_TEST(SkVM_Assembler, r) {
    // Easiest way to generate test cases is
    //
    //   echo '...some asm...' | llvm-mc -show-encoding -x86-asm-syntax=intel
    //
    // The -x86-asm-syntax=intel bit is optional, controlling the
    // input syntax only; the output will always be AT&T  op x,y,dst style.
    // Our APIs read more like Intel op dst,x,y as op(dst,x,y), so I find
    // that a bit easier to use here, despite maybe favoring AT&T overall.

    using A = skvm::Assembler;
    // Our exit strategy from AVX code.
    test_asm(r, [&](A& a) {
        a.vzeroupper();
        a.ret();
    },{
        0xc5, 0xf8, 0x77,
        0xc3,
    });

    // Align should pad with nop().
    test_asm(r, [&](A& a) {
        a.ret();
        a.align(4);
    },{
        0xc3,
        0x90, 0x90, 0x90,
    });

    test_asm(r, [&](A& a) {
        a.add(A::rax, 8);       // Always good to test rax.
        a.sub(A::rax, 32);

        a.add(A::rdi, 12);      // Last 0x48 REX
        a.sub(A::rdi, 8);

        a.add(A::r8 , 7);       // First 0x4c REX
        a.sub(A::r8 , 4);

        a.add(A::rsi, 128);     // Requires 4 byte immediate.
        a.sub(A::r8 , 1000000);
    },{
        0x48, 0x83, 0b11'000'000, 0x08,
        0x48, 0x83, 0b11'101'000, 0x20,

        0x48, 0x83, 0b11'000'111, 0x0c,
        0x48, 0x83, 0b11'101'111, 0x08,

        0x4c, 0x83, 0b11'000'000, 0x07,
        0x4c, 0x83, 0b11'101'000, 0x04,

        0x48, 0x81, 0b11'000'110, 0x80, 0x00, 0x00, 0x00,
        0x4c, 0x81, 0b11'101'000, 0x40, 0x42, 0x0f, 0x00,
    });


    test_asm(r, [&](A& a) {
        a.vpaddd (A::ymm0, A::ymm1, A::ymm2);  // Low registers and 0x0f map     -> 2-byte VEX.
        a.vpaddd (A::ymm8, A::ymm1, A::ymm2);  // A high dst register is ok      -> 2-byte VEX.
        a.vpaddd (A::ymm0, A::ymm8, A::ymm2);  // A high first argument register -> 2-byte VEX.
        a.vpaddd (A::ymm0, A::ymm1, A::ymm8);  // A high second argument         -> 3-byte VEX.
        a.vpmulld(A::ymm0, A::ymm1, A::ymm2);  // Using non-0x0f map instruction -> 3-byte VEX.
        a.vpsubd (A::ymm0, A::ymm1, A::ymm2);  // Test vpsubd to ensure argument order is right.
    },{
        /*    VEX     */ /*op*/ /*modRM*/
        0xc5,       0xf5, 0xfe, 0xc2,
        0xc5,       0x75, 0xfe, 0xc2,
        0xc5,       0xbd, 0xfe, 0xc2,
        0xc4, 0xc1, 0x75, 0xfe, 0xc0,
        0xc4, 0xe2, 0x75, 0x40, 0xc2,
        0xc5,       0xf5, 0xfa, 0xc2,
    });

    test_asm(r, [&](A& a) {
        a.vpsrld(A::ymm15, A::ymm2, 8);
        a.vpsrld(A::ymm0 , A::ymm8, 5);
    },{
        0xc5,     0x85, 0x72,0xd2, 0x08,
        0xc4,0xc1,0x7d, 0x72,0xd0, 0x05,
    });

    test_asm(r, [&](A& a) {
        a.vpermq(A::ymm1, A::ymm2, 5);
    },{
        0xc4,0xe3,0xfd, 0x00,0xca, 0x05,
    });
}

#endif