/**
 * Copyright (c) 2020, Timothy Stack
 *
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * * Redistributions of source code must retain the above copyright notice, this
 * list of conditions and the following disclaimer.
 * * Redistributions in binary form must reproduce the above copyright notice,
 * this list of conditions and the following disclaimer in the documentation
 * and/or other materials provided with the distribution.
 * * Neither the name of Timothy Stack nor the names of its contributors
 * may be used to endorse or promote products derived from this software
 * without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ''AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include "unique_path.hh"

#include "config.h"

void
unique_path_generator::add_source(
    const std::shared_ptr<unique_path_source>& path_source)
{
    ghc::filesystem::path path = path_source->get_path();

    path_source->set_unique_path(path.filename());
    path_source->set_path_prefix(path.parent_path());
    this->upg_unique_paths[path.filename()].push_back(path_source);
}

void
unique_path_generator::generate()
{
    int loop_count = 0;

    while (!this->upg_unique_paths.empty()) {
        std::vector<std::shared_ptr<unique_path_source>> collisions;

        for (const auto& pair : this->upg_unique_paths) {
            if (pair.second.size() == 1) {
                if (loop_count > 0) {
                    std::shared_ptr<unique_path_source> src = pair.second[0];

                    src->set_unique_path("[" + src->get_unique_path());
                }

                this->upg_max_len
                    = std::max(this->upg_max_len,
                               pair.second[0]->get_unique_path().size());
            } else {
                bool all_common = true;

                do {
                    std::string common;

                    for (auto& src : pair.second) {
                        auto& path = src->get_path_prefix();

                        if (common.empty()) {
                            common = path.filename();
                            if (common.empty()) {
                                all_common = false;
                            }
                        } else if (common != path.filename()) {
                            all_common = false;
                        }
                    }

                    if (all_common) {
                        for (auto& src : pair.second) {
                            auto& path = src->get_path_prefix();
                            auto par = path.parent_path();

                            if (path.empty() || path == par) {
                                all_common = false;
                            } else {
                                src->set_path_prefix(path.parent_path());
                            }
                        }
                    }
                } while (all_common);

                collisions.insert(
                    collisions.end(), pair.second.begin(), pair.second.end());
            }
        }

        this->upg_unique_paths.clear();

        for (auto& src : collisions) {
            const auto unique_path = src->get_unique_path();
            auto& prefix = src->get_path_prefix();

            if (loop_count == 0) {
                src->set_unique_path(prefix.filename().string() + "]/"
                                     + unique_path);
            } else {
                src->set_unique_path(prefix.filename().string() + "/"
                                     + unique_path);
            }

            ghc::filesystem::path parent = prefix.parent_path();

            src->set_path_prefix(parent);

            if (parent.empty() || parent == prefix) {
                src->set_unique_path("[" + src->get_unique_path());
            } else {
                this->upg_unique_paths[src->get_unique_path()].push_back(src);
            }
        }

        loop_count += 1;
    }
}
