/*
 * Copyright 2016 Google Inc.
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */

#include "stdio.h"
#include <fstream>
#include "SkSLCompiler.h"
#include "GrContextOptions.h"

/**
 * Very simple standalone executable to facilitate testing.
 */
int main(int argc, const char** argv) {
    if (argc != 3) {
        printf("usage: skslc <input> <output>\n");
        exit(1);
    }
    SkSL::Program::Kind kind;
    size_t len = strlen(argv[1]);
    if (len > 5 && !strcmp(argv[1] + strlen(argv[1]) - 5, ".vert")) {
        kind = SkSL::Program::kVertex_Kind;
    } else if (len > 5 && !strcmp(argv[1] + strlen(argv[1]) - 5, ".frag")) {
        kind = SkSL::Program::kFragment_Kind;
    } else if (len > 5 && !strcmp(argv[1] + strlen(argv[1]) - 5, ".geom")) {
        kind = SkSL::Program::kGeometry_Kind;
    } else {
        printf("input filename must end in '.vert', '.frag', or '.geom'\n");
        exit(1);
    }

    std::ifstream in(argv[1]);
    std::string stdText((std::istreambuf_iterator<char>(in)),
                        std::istreambuf_iterator<char>());
    SkString text(stdText.c_str());
    if (in.rdstate()) {
        printf("error reading '%s'\n", argv[1]);
        exit(2);
    }
    SkSL::Program::Settings settings;
    sk_sp<GrShaderCaps> caps = SkSL::ShaderCapsFactory::Default();
    settings.fCaps = caps.get();
    SkString name(argv[2]);
    if (name.endsWith(".spirv")) {
        SkFILEWStream out(argv[2]);
        SkSL::Compiler compiler;
        if (!out.isValid()) {
            printf("error writing '%s'\n", argv[2]);
            exit(4);
        }
        std::unique_ptr<SkSL::Program> program = compiler.convertProgram(kind, text, settings);
        if (!program || !compiler.toSPIRV(*program, out)) {
            printf("%s", compiler.errorText().c_str());
            exit(3);
        }
    } else if (name.endsWith(".glsl")) {
        SkFILEWStream out(argv[2]);
        SkSL::Compiler compiler;
        if (!out.isValid()) {
            printf("error writing '%s'\n", argv[2]);
            exit(4);
        }
        std::unique_ptr<SkSL::Program> program = compiler.convertProgram(kind, text, settings);
        if (!program || !compiler.toGLSL(*program, out)) {
            printf("%s", compiler.errorText().c_str());
            exit(3);
        }
    } else {
        printf("expected output filename to end with '.spirv' or '.glsl'");
    }
}