/**
 * src/common/generators/generators.h
 *
 * Copyright (c) 2021-2023 Bartek Kryza <bkryza@gmail.com>
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
#pragma once

#include "class_diagram/generators/json/class_diagram_generator.h"
#include "class_diagram/generators/plantuml/class_diagram_generator.h"
#include "cli/cli_handler.h"
#include "common/generators/generators.h"
#include "common/model/diagram_filter.h"
#include "config/config.h"
#include "include_diagram/generators/plantuml/include_diagram_generator.h"
#include "package_diagram/generators/plantuml/package_diagram_generator.h"
#include "sequence_diagram/generators/plantuml/sequence_diagram_generator.h"
#include "util/util.h"
#include "version.h"

#include <clang/Frontend/CompilerInstance.h>
#include <clang/Tooling/CompilationDatabase.h>
#include <clang/Tooling/Tooling.h>

#include <cstring>
#include <filesystem>
#include <fstream>
#include <future>
#include <iostream>
#include <map>
#include <string>
#include <util/thread_pool_executor.h>
#include <vector>

namespace clanguml::common::generators {

void find_translation_units_for_diagrams(
    const std::vector<std::string> &diagram_names,
    clanguml::config::config &config,
    const std::vector<std::string> &compilation_database_files,
    std::map<std::string, std::vector<std::string>> &translation_units_map)
{
    for (const auto &[name, diagram] : config.diagrams) {
        // If there are any specific diagram names provided on the command line,
        // and this diagram is not in that list - skip it
        if (!diagram_names.empty() && !util::contains(diagram_names, name))
            continue;

        // If glob is not defined use all translation units from the
        // compilation database
        if (!diagram->glob.has_value) {
            translation_units_map[name] = compilation_database_files;
        }
        // Otherwise, get all translation units matching the glob from diagram
        // configuration
        else {
            const std::vector<std::string> translation_units =
                diagram->get_translation_units();

            std::vector<std::string> valid_translation_units{};
            std::copy_if(compilation_database_files.begin(),
                compilation_database_files.end(),
                std::back_inserter(valid_translation_units),
                [&translation_units](const auto &tu) {
                    return util::contains(translation_units, tu);
                });

            translation_units_map[name] = std::move(valid_translation_units);
        }
    }
}

template <typename DiagramModel, typename DiagramConfig,
    typename TranslationUnitVisitor>
class diagram_ast_consumer : public clang::ASTConsumer {
    TranslationUnitVisitor visitor_;

public:
    explicit diagram_ast_consumer(clang::CompilerInstance &ci,
        DiagramModel &diagram, const DiagramConfig &config)
        : visitor_{ci.getSourceManager(), diagram, config}
    {
    }

    void HandleTranslationUnit(clang::ASTContext &ast_context) override
    {
        visitor_.TraverseDecl(ast_context.getTranslationUnitDecl());
        visitor_.finalize();
    }
};

template <typename DiagramModel, typename DiagramConfig,
    typename DiagramVisitor>
class diagram_fronted_action : public clang::ASTFrontendAction {
public:
    explicit diagram_fronted_action(
        DiagramModel &diagram, const DiagramConfig &config)
        : diagram_{diagram}
        , config_{config}
    {
    }

    std::unique_ptr<clang::ASTConsumer> CreateASTConsumer(
        clang::CompilerInstance &CI, clang::StringRef /*file*/) override
    {
        return std::make_unique<
            diagram_ast_consumer<DiagramModel, DiagramConfig, DiagramVisitor>>(
            CI, diagram_, config_);
    }

protected:
    bool BeginSourceFileAction(clang::CompilerInstance &ci) override
    {
        LOG_DBG("Visiting source file: {}", getCurrentFile().str());

        if constexpr (std::is_same_v<DiagramModel,
                          clanguml::include_diagram::model::diagram>) {
            auto find_includes_callback =
                std::make_unique<typename DiagramVisitor::include_visitor>(
                    ci.getSourceManager(), diagram_, config_);

            clang::Preprocessor &pp = ci.getPreprocessor();

            pp.addPPCallbacks(std::move(find_includes_callback));
        }

        return true;
    }

private:
    DiagramModel &diagram_;
    const DiagramConfig &config_;
};

template <typename DiagramModel, typename DiagramConfig,
    typename DiagramVisitor>
class diagram_action_visitor_factory
    : public clang::tooling::FrontendActionFactory {
public:
    explicit diagram_action_visitor_factory(
        DiagramModel &diagram, const DiagramConfig &config)
        : diagram_{diagram}
        , config_{config}
    {
    }

    std::unique_ptr<clang::FrontendAction> create() override
    {
        return std::make_unique<diagram_fronted_action<DiagramModel,
            DiagramConfig, DiagramVisitor>>(diagram_, config_);
    }

private:
    DiagramModel &diagram_;
    const DiagramConfig &config_;
};

template <typename DiagramModel, typename DiagramConfig,
    typename DiagramVisitor>
std::unique_ptr<DiagramModel> generate(
    const clang::tooling::CompilationDatabase &db, const std::string &name,
    DiagramConfig &config, const std::vector<std::string> &translation_units,
    bool /*verbose*/ = false)
{
    LOG_INFO("Generating diagram {}.puml", name);

    auto diagram = std::make_unique<DiagramModel>();
    diagram->set_name(name);
    diagram->set_filter(
        std::make_unique<model::diagram_filter>(*diagram, config));

    LOG_DBG("Found translation units for diagram {}: {}", name,
        fmt::join(translation_units, ", "));

    clang::tooling::ClangTool clang_tool(db, translation_units);
    auto action_factory =
        std::make_unique<diagram_action_visitor_factory<DiagramModel,
            DiagramConfig, DiagramVisitor>>(*diagram, config);

    auto res = clang_tool.run(action_factory.get());

    if (res != 0) {
        throw std::runtime_error("Diagram " + name + " generation failed");
    }

    diagram->set_complete(true);

    return diagram;
}

void generate_diagram(const std::string &od, const std::string &name,
    std::shared_ptr<clanguml::config::diagram> diagram,
    const clang::tooling::CompilationDatabase &db,
    const std::vector<std::string> &translation_units,
    const std::vector<clanguml::common::generator_type_t> generators,
    bool verbose)
{
    using clanguml::common::generator_type_t;
    using clanguml::common::model::diagram_t;
    using clanguml::config::class_diagram;
    using clanguml::config::include_diagram;
    using clanguml::config::package_diagram;
    using clanguml::config::sequence_diagram;

    if (diagram->type() == diagram_t::kClass) {
        using diagram_config = class_diagram;
        using diagram_model = clanguml::class_diagram::model::diagram;
        using diagram_visitor =
            clanguml::class_diagram::visitor::translation_unit_visitor;

        auto model = clanguml::common::generators::generate<diagram_model,
            diagram_config, diagram_visitor>(db, diagram->name,
            dynamic_cast<diagram_config &>(*diagram), translation_units,
            verbose);

        for (const auto generator_type : generators) {
            if (generator_type == generator_type_t::plantuml) {
                auto path =
                    std::filesystem::path{od} / fmt::format("{}.puml", name);
                std::ofstream ofs;
                ofs.open(path, std::ofstream::out | std::ofstream::trunc);
                ofs << clanguml::class_diagram::generators::plantuml::generator(
                    dynamic_cast<diagram_config &>(*diagram), *model);

                ofs.close();

                LOG_INFO("Written {} diagram to {}", name, path.string());
            }
            else if (generator_type == generator_type_t::json) {
                auto path =
                    std::filesystem::path{od} / fmt::format("{}.json", name);
                std::ofstream ofs;
                ofs.open(path, std::ofstream::out | std::ofstream::trunc);
                ofs << clanguml::class_diagram::generators::json::generator(
                    dynamic_cast<diagram_config &>(*diagram), *model);

                ofs.close();

                LOG_INFO("Written {} diagram to {}", name, path.string());
            }
        }
    }
    else if (diagram->type() == diagram_t::kSequence) {
        using diagram_config = sequence_diagram;
        using diagram_model = clanguml::sequence_diagram::model::diagram;
        using diagram_visitor =
            clanguml::sequence_diagram::visitor::translation_unit_visitor;

        auto model = clanguml::common::generators::generate<diagram_model,
            diagram_config, diagram_visitor>(db, diagram->name,
            dynamic_cast<diagram_config &>(*diagram), translation_units,
            verbose);

        auto path = std::filesystem::path{od} / fmt::format("{}.puml", name);
        std::ofstream ofs;

        ofs.open(path, std::ofstream::out | std::ofstream::trunc);
        ofs << clanguml::sequence_diagram::generators::plantuml::generator(
            dynamic_cast<clanguml::config::sequence_diagram &>(*diagram),
            *model);

        ofs.close();

        LOG_INFO("Written {} diagram to {}", name, path.string());
    }
    else if (diagram->type() == diagram_t::kPackage) {
        using diagram_config = package_diagram;
        using diagram_model = clanguml::package_diagram::model::diagram;
        using diagram_visitor =
            clanguml::package_diagram::visitor::translation_unit_visitor;

        auto model = clanguml::common::generators::generate<diagram_model,
            diagram_config, diagram_visitor>(db, diagram->name,
            dynamic_cast<diagram_config &>(*diagram), translation_units,
            verbose);

        auto path = std::filesystem::path{od} / fmt::format("{}.puml", name);
        std::ofstream ofs;
        ofs.open(path, std::ofstream::out | std::ofstream::trunc);

        ofs << clanguml::package_diagram::generators::plantuml::generator(
            dynamic_cast<diagram_config &>(*diagram), *model);

        ofs.close();

        LOG_INFO("Written {} diagram to {}", name, path.string());
    }
    else if (diagram->type() == diagram_t::kInclude) {
        using diagram_config = include_diagram;
        using diagram_model = clanguml::include_diagram::model::diagram;
        using diagram_visitor =
            clanguml::include_diagram::visitor::translation_unit_visitor;

        auto model = clanguml::common::generators::generate<diagram_model,
            diagram_config, diagram_visitor>(db, diagram->name,
            dynamic_cast<diagram_config &>(*diagram), translation_units,
            verbose);

        auto path = std::filesystem::path{od} / fmt::format("{}.puml", name);
        std::ofstream ofs;
        ofs.open(path, std::ofstream::out | std::ofstream::trunc);

        ofs << clanguml::include_diagram::generators::plantuml::generator(
            dynamic_cast<diagram_config &>(*diagram), *model);

        ofs.close();

        LOG_INFO("Written {} diagram to {}", name, path.string());
    }
}

void generate_diagrams(const std::vector<std::string> &diagram_names,
    clanguml::config::config &config, const std::string &od,
    const std::unique_ptr<clang::tooling::CompilationDatabase> &db,
    const int verbose, const unsigned int thread_count,
    const std::vector<clanguml::common::generator_type_t> generators,
    const std::map<std::string, std::vector<std::string>>
        &translation_units_map)
{
    util::thread_pool_executor generator_executor{thread_count};
    std::vector<std::future<void>> futs;

    for (const auto &[name, diagram] : config.diagrams) {
        // If there are any specific diagram names provided on the command line,
        // and this diagram is not in that list - skip it
        if (!diagram_names.empty() && !util::contains(diagram_names, name))
            continue;

        const auto &valid_translation_units = translation_units_map.at(name);

        if (valid_translation_units.empty()) {
            LOG_ERROR(
                "Diagram {} generation failed: no translation units found",
                name);
            continue;
        }

        futs.emplace_back(generator_executor.add(
            [&od, &generators, &name = name, &diagram = diagram,
                db = std::ref(*db), translation_units = valid_translation_units,
                verbose]() {
                try {
                    generate_diagram(od, name, diagram, db, translation_units,
                        generators, verbose != 0);
                }
                catch (std::runtime_error &e) {
                    LOG_ERROR(e.what());
                }
            }));
    }

    for (auto &fut : futs) {
        fut.get();
    }
}

} // namespace clanguml::common::generators