/**
 * src/uml/sequence_diagram_visitor.h
 *
 * Copyright (c) 2021 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 "cx/cursor.h"
#include "sequence_diagram_model.h"

#include <clang-c/CXCompilationDatabase.h>
#include <clang-c/Index.h>
#include <spdlog/spdlog.h>

#include <functional>
#include <memory>
#include <string>

namespace clanguml {
namespace visitor {
namespace sequence_diagram {

using clanguml::model::sequence_diagram::activity;
using clanguml::model::sequence_diagram::diagram;
using clanguml::model::sequence_diagram::message;
using clanguml::model::sequence_diagram::message_t;

struct tu_context {
    tu_context(diagram &d_, const clanguml::config::sequence_diagram &config_)
        : d{d_}
        , config{config_}
    {
    }

    std::vector<std::string> namespace_;
    cx::cursor current_method;
    clanguml::model::sequence_diagram::diagram &d;
    const clanguml::config::sequence_diagram &config;
};

static enum CXChildVisitResult translation_unit_visitor(
    CXCursor cx_cursor, CXCursor cx_parent, CXClientData client_data)
{
    struct tu_context *ctx = (struct tu_context *)client_data;

    enum CXChildVisitResult ret = CXChildVisit_Break;

    cx::cursor cursor{std::move(cx_cursor)};
    cx::cursor parent{std::move(cx_parent)};

    if (cursor.spelling().empty()) {
        return CXChildVisit_Recurse;
    }

    switch (cursor.kind()) {
    case CXCursor_FunctionTemplate:
    case CXCursor_CXXMethod:
    case CXCursor_FunctionDecl:
        ctx->current_method = cursor;
        ret = CXChildVisit_Recurse;
        break;
    case CXCursor_CallExpr: {
        auto referenced = cursor.referenced();
        auto referenced_type = referenced.type();
        auto referenced_cursor_name = referenced.display_name();

        auto semantic_parent = referenced.semantic_parent();
        auto sp_name = semantic_parent.fully_qualified();
        auto lexical_parent = cursor.lexical_parent();
        auto lp_name = lexical_parent.spelling();

        CXFile f;
        unsigned int line{};
        unsigned int column{};
        unsigned int offset{};
        clang_getFileLocation(cursor.location(), &f, &line, &column, &offset);
        std::string file{clang_getCString(clang_getFileName(f))};

        auto &d = ctx->d;
        auto &config = ctx->config;
        if (referenced.kind() == CXCursor_CXXMethod) {
            if (config.should_include(sp_name)) {
                // Get calling object
                std::string caller{};
                if (ctx->current_method.semantic_parent()
                        .is_translation_unit() ||
                    ctx->current_method.semantic_parent().is_namespace()) {
                    caller = ctx->current_method.semantic_parent()
                                 .fully_qualified() +
                        "::" + ctx->current_method.spelling() + "()";
                }
                else {
                    caller =
                        ctx->current_method.semantic_parent().fully_qualified();
                }

                auto caller_usr = ctx->current_method.usr();
                // Get called object
                auto callee = referenced.semantic_parent().fully_qualified();
                auto callee_usr = referenced.semantic_parent().usr();

                // Get called method
                auto called_message = cursor.spelling();

                // Found method call: CXCursorKind () const
                spdlog::debug("Adding method call at line {}:{} to diagram {}"
                              "\n\tCURRENT_METHOD: {}\n\tFROM: '{}'\n\tTO: "
                              "{}\n\tMESSAGE: {}\n\tFROM_USR: {}\n\tTO_USR: "
                              "{}\n\tRETURN_TYPE: {}",
                    file, line, d.name, ctx->current_method.spelling(), caller,
                    callee, called_message, caller_usr, callee_usr,
                    referenced.type().result_type().spelling());

                message m;
                m.type = message_t::kCall;
                m.from = caller;
                m.from_usr = caller_usr;
                m.line = line;
                m.to = callee;
                m.to_usr = referenced.usr();
                m.message = called_message;
                m.return_type = referenced.type().result_type().spelling();

                if (d.sequences.find(caller_usr) == d.sequences.end()) {
                    activity a;
                    a.usr = caller_usr;
                    a.from = caller;
                    d.sequences.insert({caller_usr, std::move(a)});
                }

                d.sequences[caller_usr].messages.emplace_back(std::move(m));
            }
        }
        else if (referenced.kind() == CXCursor_FunctionDecl) {
            // TODO
        }

        ret = CXChildVisit_Recurse;
        break;
    }
    case CXCursor_Namespace: {
        ret = CXChildVisit_Recurse;
        break;
    }
    default:
        ret = CXChildVisit_Recurse;
    }

    return ret;
}
}
}
}