#include "quam/archive.h"

#include "quam/pack.h"
#include "quam/wad2.h"

#include <QIcon>

namespace Arc {
	Option<ArcType> getArchiveType(std::istream &st) noexcept {
		try {
			auto pos = st.tellg();
			auto magic = readBytes<4>(st);
			st.seekg(pos);
			if(magic == std::array{'P', 'A', 'C', 'K'}) {return ArcType::Pack;}
			if(magic == std::array{'W', 'A', 'D', '2'}) {return ArcType::Wad2;}
		} catch(...) {
		}
		return None;
	}

	Dir Dir::readArchive(std::istream &st, ArcType type) {
		switch(type) {
			case ArcType::Pack: return readPack(st);
			case ArcType::Wad2: return readWad2(st);
		}
	}

	ArcInfo::ArcInfo(ArcType arcType) noexcept :
		type{arcType}
	{
		switch(type) {
			case ArcType::Pack:
				pathMaxChars  = 56;
				validatorType = PackValidator::staticMetaObject;
				break;
			case ArcType::Wad2:
				pathMaxChars  = 16;
				validatorType = Wad2Validator::staticMetaObject;
				break;
		}
	}

	Arc::Arc(std::istream &st, QObject *parent) :
		QObject{parent},
		info{ArcInfo(orThrow(getArchiveType(st),
		             FileFormatError("not an archive")))},
		root{Dir::readArchive(st, info.type)},
		validator{qobject_cast<QValidator *>(info.validatorType
		                                         .newInstance(Q_ARG(QObject *,
		                                                            this)))}
	{
	}

	Arc::~Arc() {
	}

	Node *Dir::findNode(std::string const &name) {
		auto it = std::find_if(begin(), end(), [&name](Node &node) {
			return node.name == name;
		});
		return it != end() ? &*it : nullptr;
	}

	Node::Node(Dir &&f, std::string &&n, FileType t) :
		superType(std::move(f)),
		name(std::move(n)),
		type(t)
	{
	}

	Node::Node(File &&f, std::string &&n, FileType t) :
		superType(std::move(f)),
		name(std::move(n)),
		type(t)
	{
	}

	Model::Model(QObject *parent) :
		QAbstractItemModel{parent},
		m_dir{nullptr}
	{
	}

	Model::~Model() {
	}

	QVariant Model::data(QModelIndex const &index, int role) const {
		if(!index.isValid()) {
			return QVariant{};
		}

		auto node = static_cast<Node *>(index.internalPointer());
		auto col  = Column(index.column());

		switch(role) {
			case Qt::DecorationRole:
				if(col == Column::Name) {
					auto icon =
						std::holds_alternative<Dir>(*node) ? "folder"
						                                   : "text-x-generic";
					return QVariant{QIcon::fromTheme(icon)};
				}
				break;
			case Qt::DisplayRole:
				switch(col) {
					case Column::Size:
						if(auto file = std::get_if<File>(node)) {
							return QVariant{QString::number(file->size())};
						}
						break;
					case Column::Type:
						return QVariant{tr(enumToString(node->type))};
					case Column::Name:
						return QVariant{tr(node->name.data())};
				}
			case Qt::UserRole:
				return QVariant::fromValue(static_cast<void *>(node));
			default:
				break;
		}
		return QVariant{};
	}

	Qt::ItemFlags Model::flags(QModelIndex const &index) const {
		if(!index.isValid()) {
			return Qt::NoItemFlags;
		} else {
			return Qt::ItemIsSelectable  |
			       Qt::ItemIsDragEnabled |
			       Qt::ItemIsEnabled     |
			       Qt::ItemNeverHasChildren;
		}
	}

	QVariant Model::headerData(int section,
	                           Qt::Orientation ori,
	                           int role) const {
		if(ori == Qt::Horizontal && role == Qt::DisplayRole) {
			switch(Column(section)) {
				case Column::Size: return QVariant{tr("Size")};
				case Column::Type: return QVariant{tr("Type")};
				case Column::Name: return QVariant{tr("Name")};
			}
		}
		return QVariant{};
	}

	QModelIndex Model::index(int row,
	                         int col,
	                         QModelIndex const &parent) const {
		if(!m_dir || !hasIndex(row, col, parent) || row > m_dir->size()) {
			return QModelIndex{};
		} else {
			return createIndex(row, col, &m_dir->at(row));
		}
	}

	QModelIndex Model::parent(QModelIndex const &) const {
		return QModelIndex{};
	}

	int Model::rowCount(QModelIndex const &) const {
		return m_dir ? m_dir->size() : 0;
	}

	int Model::columnCount(QModelIndex const &) const {
		return enumMax<Column>();
	}

	Dir *Model::dir() const {
		return m_dir;
	}

	void Model::setDir(Dir *to) {
		auto from = m_dir;
		if(to != from) {
			emit layoutAboutToBeChanged();
			for(int row = 0, rows = rowCount(); row < rows; row++) {
				for(int col = 0, cols = columnCount(); col < cols; col++) {
					changePersistentIndex(index(row, col), QModelIndex{});
				}
			}
			m_dir = to;
			emit layoutChanged();
			emit dirChanged(from, to);
		}
	}

	void Model::setDirToIndex(QModelIndex const &ind) {
		auto node = static_cast<Node *>(ind.data(Qt::UserRole).value<void *>());
		if(auto dir = std::get_if<Dir>(node)) {
			setDir(dir);
		}
	}
}

// EOF