/**
 * \file imperative/tablegen/helper.h
 * MegEngine is Licensed under the Apache License, Version 2.0 (the "License")
 *
 * Copyright (c) 2014-2021 Megvii Inc. All rights reserved.
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT ARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 */
#pragma once

#include <iostream>
#include <string>
#include <vector>

#include "llvm/Support/CommandLine.h"
#include "llvm/Support/FormatVariadic.h"
#include "llvm/Support/InitLLVM.h"
#include "llvm/Support/Signals.h"
#include "llvm/TableGen/Main.h"
#include "llvm/TableGen/Record.h"
#include "llvm/TableGen/TableGenBackend.h"
#include "mlir/TableGen/Attribute.h"
#include "mlir/TableGen/Format.h"
#include "mlir/TableGen/Operator.h"

using llvm::formatv;
using llvm::Record;
using llvm::StringRef;

#define ASSERT(stmt, msg)                                                  \
    if (!(stmt)) {                                                         \
        std::cerr << "\033[1;31m"                                          \
                  << "tablegen autogen abort due to: " << msg << "\033[0m" \
                  << std::endl;                                            \
        exit(1);                                                           \
    }

namespace mlir {
namespace tblgen {
template <typename ConcreteType>
struct MgbInterface : public ConcreteType {
    MgbInterface() = delete;
    MgbInterface(const MgbInterface&) = delete;
    MgbInterface(MgbInterface&&) = delete;
    ~MgbInterface() = delete;
};

struct MgbAttrWrapperBase : public MgbInterface<Attribute> {
private:
    struct RecordVisitor : public MgbInterface<Constraint> {
    public:
        static bool classof(const Constraint*) { return true; }

        const llvm::Record* getDef() const { return def; }
    };

public:
    static bool classof(const Attribute* attr) {
        return attr->isSubClassOf("MgbAttrWrapperBase");
    }

    const llvm::Record* getBaseRecord() const {
        auto baseAttr = getBaseAttr();
        return llvm::cast<RecordVisitor>(baseAttr).getDef();
    }
    llvm::StringRef getUnderlyingType() const {
        return def->getValueAsString("underlyingType");
    }
};

struct MgbEnumAttrMixin : public MgbAttrWrapperBase {
    static bool classof(const Attribute* attr) {
        return attr->getBaseAttr().isSubClassOf("MgbEnumAttrMixin");
    }

    llvm::StringRef getParentNamespace() const {
        return getBaseRecord()->getValueAsString("parentNamespace");
    }
    llvm::StringRef getEnumName() const {
        return getBaseRecord()->getValueAsString("enumName");
    }
    std::vector<StringRef> getEnumMembers() const {
        return getBaseRecord()->getValueAsListOfStrings("enumMembers");
    }
    bool supportToString() const {
        return getBaseRecord()->getValueAsBit("supportToString");
    }
    bool getEnumCombinedFlag() const {
        return getBaseRecord()->getValueAsBit("enumCombined");
    }
};

struct MgbHashableAttrMixin : public MgbAttrWrapperBase {
    static bool classof(const Attribute* attr) {
        return attr->getBaseAttr().isSubClassOf("MgbHashableAttrMixin");
    }

    llvm::StringRef getHashFunctionTemplate() const {
        return getBaseRecord()->getValueAsString("hashFunction");
    }
    llvm::StringRef getCmpFunctionTemplate() const {
        return getBaseRecord()->getValueAsString("cmpFunction");
    }
    llvm::StringRef getReprFunctionTemplate() const {
        return getBaseRecord()->getValueAsString("reprFunction");
    }
};

struct MgbAliasAttrMixin : public MgbAttrWrapperBase {
    static bool classof(const Attribute* attr) {
        return attr->getBaseAttr().isSubClassOf("MgbAliasAttrMixin");
    }

    Attribute getAliasBase() const {
        return Attribute(getBaseRecord()->getValueAsDef("aliasBase"));
    }
};

class MgbPackedParam {
public:
    MgbPackedParam(Record* def_) : def(def_) {
        auto&& dag = def->getValueAsDag("fields");
        for (size_t i = 0; i < dag->getNumArgs(); ++i) {
            fields.push_back(
                    {dag->getArgNameStr(i),
                     Attribute(llvm::cast<llvm::DefInit>(dag->getArg(i)))});
        }
    }

    llvm::StringRef getFullName() const { return def->getValueAsString("fullName"); }
    std::vector<NamedAttribute> getFields() const { return fields; }
    llvm::StringRef getAccessor() const {
        return def->getValueAsString("paramAccessor");
    }

private:
    std::vector<NamedAttribute> fields;
    Record* def;
};

struct MgbOpBase : public MgbInterface<Operator> {
    static bool isPackedParam(Record* def) {
        return def->isSubClassOf("MgbPackedParamBase");
    }

public:
    static bool classof(const Operator* op) {
        return op->getDef().isSubClassOf("MgbOp");
    }

    std::vector<NamedAttribute> getMgbAttributes() const {
        std::vector<NamedAttribute> ret;
        for (auto&& i : getAttributes()) {
            if (isa<MgbAttrWrapperBase>(i.attr)) {
                ret.push_back(i);
            }
        }
        return ret;
    }
    std::vector<NamedAttribute> getExtraArguments() const {
        std::vector<NamedAttribute> ret;
        auto&& dag = getDef().getValueAsDag("extraArguments");
        for (size_t i = 0; i < dag->getNumArgs(); ++i) {
            ret.push_back(
                    {dag->getArgNameStr(i),
                     Attribute(llvm::cast<llvm::DefInit>(dag->getArg(i)))});
        }
        return ret;
    }
    llvm::Optional<StringRef> getExtraOpdefDecl() const {
        return getDef().getValueAsOptionalString("extraOpdefDecl");
    }
    std::vector<MgbPackedParam> getPackedParams() const {
        std::vector<MgbPackedParam> ret;
        for (auto&& i : getDef().getValueAsListOfDefs("dnnParams")) {
            if (isPackedParam(i)) {
                ret.emplace_back(i);
            }
        }
        return ret;
    }
    std::string getNameFunctionTemplate() const {
        if (auto f = getDef().getValueAsOptionalString("nameFunction")) {
            return f.getValue().str();
        }
        return formatv("    return \"{0}\";\n", getCppClassName());
    }
};

struct MgbHashableOpMixin : public MgbOpBase {
private:
    std::string getDefaultHashFunction() const {
        std::string body = "    size_t val = mgb::hash($_self.dyn_typeinfo());\n";
        if (!getMgbAttributes().empty()) {
            auto getHashFunc = [&](auto&& iter) {
                auto&& attr = llvm::cast<MgbHashableAttrMixin>(iter.attr);
                return attr.getHashFunctionTemplate();
            };
            mlir::tblgen::FmtContext ctx;
            for (auto&& it : getMgbAttributes()) {
                body +=
                        formatv("    val = mgb::hash_pair_combine(val, {0});\n",
                                mlir::tblgen::tgfmt(
                                        getHashFunc(it), &ctx, "$_self." + it.name));
            }
        }
        body += "    return val;\n";
        return body;
    }
    std::string getDefaultCmpFunction() const {
        std::string body;
        if (!getMgbAttributes().empty()) {
            mlir::tblgen::FmtContext ctx;
            for (auto&& it : getMgbAttributes()) {
                auto&& attr = llvm::cast<MgbHashableAttrMixin>(it.attr);
                body +=
                        formatv("    if ({0}) return false;\n",
                                mlir::tblgen::tgfmt(
                                        attr.getCmpFunctionTemplate(), &ctx,
                                        "$0." + it.name, "$1." + it.name));
            }
        }
        body += "    return true;\n";
        return body;
    }
    std::string getDefaultPropsFunction() const {
        std::string body =
                "    std::vector<std::pair<const char*, std::string>> props_;\n";
        if (!getMgbAttributes().empty()) {
            mlir::tblgen::FmtContext ctx;
            for (auto&& it : getMgbAttributes()) {
                if (auto* enumAttr = llvm::dyn_cast<MgbEnumAttrMixin>(&it.attr)) {
                    body += formatv("    switch ({0}){{\n", "$_self." + it.name);
                    for (auto&& enumMember : enumAttr->getEnumMembers()) {
                        size_t d1 = enumMember.find(' ');
                        size_t d2 = enumMember.find('=');
                        size_t d = d1 <= d2 ? d1 : d2;
                        body += formatv(
                                "    case {0}::{1}::{2}:\n", getCppClassName(),
                                enumAttr->getEnumName(), enumMember.substr(0, d));
                        body +=
                                formatv("        props_.emplace_back(\"{0}\", "
                                        "\"{1}\");\n",
                                        it.name, enumMember.substr(0, d));
                        body += "        break;\n";
                    }
                    body += "    default: break;\n";
                    body += "    }\n";
                } else {
                    auto&& attr = llvm::cast<MgbHashableAttrMixin>(it.attr);
                    body +=
                            formatv("    props_.emplace_back(\"{0}\", {1});\n", it.name,
                                    mlir::tblgen::tgfmt(
                                            attr.getReprFunctionTemplate(), &ctx,
                                            "$_self." + it.name));
                }
            }
        }
        body += "    return props_;\n";
        return body;
    }

public:
    static bool classof(const Operator* op) {
        return op->getDef().isSubClassOf("MgbHashableOpMixin");
    }

    std::string getHashFunctionTemplate() const {
        if (auto f = getDef().getValueAsOptionalString("hashFunction")) {
            return f.getValue().str();
        }
        return getDefaultHashFunction();
    }
    std::string getCmpFunctionTemplate() const {
        if (auto f = getDef().getValueAsOptionalString("cmpFunction")) {
            return f.getValue().str();
        }
        return getDefaultCmpFunction();
    }
    std::string getPropsFunctionTemplate() const {
        if (auto f = getDef().getValueAsOptionalString("propsFunction")) {
            return f.getValue().str();
        }
        return getDefaultPropsFunction();
    }
};

using MgbAttrWrapper = mlir::tblgen::MgbAttrWrapperBase;
using MgbEnumAttr = mlir::tblgen::MgbEnumAttrMixin;
using MgbHashableAttr = mlir::tblgen::MgbHashableAttrMixin;
using MgbAliasAttr = mlir::tblgen::MgbAliasAttrMixin;
using MgbOp = mlir::tblgen::MgbOpBase;
using MgbHashableOp = mlir::tblgen::MgbHashableOpMixin;

static inline void foreach_operator(
        llvm::RecordKeeper& keeper, std::function<void(MgbOp&)> callback) {
    auto op_base_class = keeper.getClass("Op");
    ASSERT(op_base_class, "could not find base class Op");
    for (auto&& i : keeper.getDefs()) {
        auto&& r = i.second;
        if (r->isSubClassOf(op_base_class)) {
            auto op = mlir::tblgen::Operator(r.get());
            if (op.getDialectName().str() == "mgb") {
                std::cerr << "\033[34;15m"
                          << "Generating " << r->getName().str() << "\033[0m"
                          << std::endl;
                callback(llvm::cast<MgbOp>(op));
            }
        }
    }
}

}  // namespace tblgen
}  // namespace mlir