#include "./resolvebuildorder.h"

#include "./manager.h"
#include "./config.h"
#include "./utilities.h"

#include <c++utilities/misc/memory.h>

#include <iostream>
#include <sstream>

using namespace std;
using namespace ApplicationUtilities;

namespace RepoIndex {

class TaskInfo
{
public:
    TaskInfo(QString name, bool onlyDependency = false, const QList<TaskInfo *> &deps = QList<TaskInfo *>());

    const QString &name() const;
    void setName(const QString &name);
    const QList<TaskInfo *> deps() const;
    void addDep(TaskInfo *dep);
    bool isDone() const;
    bool isVisited() const;
    bool isOnlyDependency() const;
    void add(QList<TaskInfo *> &results);
    static void addAll(const QList<TaskInfo *> &tasks, QList<TaskInfo *> &results);
    static TaskInfo *find(const QList<TaskInfo *> &tasks, const QString &name);

private:
    QString m_name;
    QList<TaskInfo *> m_deps;
    bool m_done;
    bool m_visited;
    bool m_onlyDep;
};

inline TaskInfo::TaskInfo(QString name, bool onlyDependency, const QList<TaskInfo *> &deps) :
    m_name(name),
    m_deps(deps),
    m_done(false),
    m_visited(false),
    m_onlyDep(onlyDependency)
{}

inline const QString &TaskInfo::name() const
{
    return m_name;
}

inline void TaskInfo::setName(const QString &name)
{
    m_name = name;
}

inline const QList<TaskInfo *> TaskInfo::deps() const
{
    return m_deps;
}

inline void TaskInfo::addDep(TaskInfo *dep)
{
    m_deps << dep;
}

inline bool TaskInfo::isDone() const
{
    return m_done;
}

inline bool TaskInfo::isVisited() const
{
    return m_visited;
}

inline bool TaskInfo::isOnlyDependency() const
{
    return m_onlyDep;
}

void TaskInfo::add(QList<TaskInfo *> &results)
{
    if(!isDone()) {
        if(isVisited()) {
            // cyclic dependency
            if(isOnlyDependency()) {
                // if this is only a dependency (which we don't want to build) don't care about it
                return;
            } else {
                throw *this;
            }
        } else {
            m_visited = true;
        }
        for(auto *dep : deps()) {
            dep->add(results);
        }
        m_done = true;
        if(!isOnlyDependency()) {
            results << this;
        }
    }
}

void TaskInfo::addAll(const QList<TaskInfo *> &tasks, QList<TaskInfo *> &results)
{
    for(auto *task : tasks) {
        task->add(results);
    }
}

TaskInfo *TaskInfo::find(const QList<TaskInfo *> &tasks, const QString &name)
{
    for(auto *task : tasks) {
        if(task->name() == name) {
            return task;
        }
    }
    return nullptr;
}

template<class ListType>
class DestroyList
{
public:
    DestroyList(ListType &list) :
        m_list(list)
    {}

    ~DestroyList()
    {
        qDeleteAll(m_list);
    }

private:
    ListType &m_list;
};

BuildOrderResolver::BuildOrderResolver(const Manager &manager) :
    m_manager(manager)
{}

QStringList BuildOrderResolver::resolve(const StringVector &packages) const
{
    cerr << shchar << "Getting package information ..." << endl;
    QList<TaskInfo *> tasks;
    tasks.reserve(packages.size());
    try {
        // add a task for each specified package
        for(const auto &pkgName : packages) {
            tasks << new TaskInfo(QString::fromLocal8Bit(pkgName.data()));
        }
        // find specified packages and their dependencies
        //for(int i = 0, size = tasks.size(); i != size; ++i) {
        //    addDeps(tasks, tasks.at(i));
        //}
        for(auto *task : tasks) {
            addDeps(tasks, task);
        }
        if(m_manager.config().isVerbose()) {
            cerr << shchar << "Relevant packages: ";
            for(const auto *task : tasks) {
                cerr << task->name().toLocal8Bit().data() << ' ';
            }
            cerr << endl;
        }
        // topo sort
        QList<TaskInfo *> results;
        try {
            results.reserve(packages.size());
            TaskInfo::addAll(tasks, results);
            QStringList names;
            names.reserve(results.size());
            for(const auto *res : results) {
                names << res->name();
            }
            return names;
        } catch (const TaskInfo &cyclic) {
            throw runtime_error("Can't resolve build order; the package " + cyclic.name().toStdString() + " is a cyclic dependency.");
        }
    } catch(...) {
        qDeleteAll(tasks);
        throw;
    }
}

void BuildOrderResolver::printResults(const QStringList &results)
{
    if(useShSyntax) {
        Utilities::printBashArray(cout, "REPOINDEX_RESULTS", results);
    } else {
        Utilities::printValues(cout, "Results", results);
    }
}

void BuildOrderResolver::addDeps(QList<TaskInfo *> &tasks, TaskInfo *task) const
{
    if(const auto pkg = m_manager.packageProviding(Dependency(task->name(), QString()))) {
        task->setName(pkg->name()); // update the name to ensure we have the acutal package name and not just a "provides" name
        addDeps(tasks, task, pkg->dependencies());
    } else {
        stringstream ss;
        ss << "The specified package \"" << task->name().toLocal8Bit().data() << "\" could not be found; TODO: search AUR for package, add AUR deps to the packages we want to build";
        throw runtime_error(ss.str());
    }
}

void BuildOrderResolver::addDeps(QList<TaskInfo *> &tasks, TaskInfo *task, const QList<Dependency> &dependencies) const
{
    for(auto &dep : dependencies) {
        if(const auto depPkg = m_manager.packageProviding(dep)) {
            auto *depTask = TaskInfo::find(tasks, depPkg->name());
            if(depTask) {
                // we've already added a task for this dependency
                // adds dependency task to the dependencies of "parent" task
                task->addDep(depTask);
            } else {
                // create new task
                tasks << (depTask = new TaskInfo(depPkg->name(), true));
                // adds dependency task to the dependencies of "parent" task
                task->addDep(depTask);
                // add dependencies of the dependency
                addDeps(tasks, depTask, depPkg->dependencies());
            }
        } else {
            stringstream ss;
            ss << "The dependency \"" << dep.name.toLocal8Bit().data() << "\" could not be found; TODO: search AUR for package, add AUR deps to the packages we want to build";
            throw runtime_error(ss.str());
        }
    }
}

} // namespace PackageManagement