#include "TableTemplate.hpp"

#include <xlsxwriter.h>
#include <charconv>
#include <iostream>
#include <map>

bool TableCell::IsDataHoldingCell() const
{
	return IsPrimaryCell() || !IsMergedCell();
}

bool TableCell::IsPrimaryCell() const
{
	return PrimaryCellLocation == Location;
}

bool TableCell::IsMergedCell() const
{
	return PrimaryCellLocation.x == -1 || PrimaryCellLocation.y == -1;
}

Vec2i TableArrayGroup::GetLeftCell() const
{
	return { Row, LeftCell };
}

Vec2i TableArrayGroup::GetRightCell() const
{
	return { Row, RightCell };
}

int TableArrayGroup::GetCount() const
{
	return RightCell - LeftCell + 1;
}

Vec2i TableArrayGroup::FindCell(std::string_view name)
{
}

TableInstantiationParameters::TableInstantiationParameters(const TableTemplate& table)
	: mTable{ &table }
{
}

TableInstantiationParameters& TableInstantiationParameters::ResetTable(const TableTemplate& newTable)
{
	mTable = &newTable;
	return *this;
}

TableInstantiationParameters TableInstantiationParameters::RebindTable(const TableTemplate& newTable) const
{
	TableInstantiationParameters result(newTable);
	result.SingularCells = this->SingularCells;
	result.ArrayGroups = this->ArrayGroups;
	return result;
}

const TableTemplate& TableInstantiationParameters::GetTable() const
{
	return *mTable;
}

bool TableTemplate::IsInstance(const Template* tmpl)
{
	return tmpl->GetKind() == KD_Table;
}

TableTemplate::TableTemplate()
	: Template(KD_Table)
{
}

int TableTemplate::GetTableWidth() const
{
	return mColumnWidths.size();
}

int TableTemplate::GetTableHeight() const
{
	return mRowHeights.size();
}

void TableTemplate::Resize(int newWidth, int newHeight)
{
	// TODO this doesn't gracefully handle resizing to a smaller size which trims some merged cells

	std::vector<TableCell> cells;
	cells.reserve(newWidth * newHeight);

	int tableWidth = GetTableWidth();
	int tableHeight = GetTableHeight();

	for (int y = 0; y < newHeight; ++y) {
		if (y >= tableHeight) {
			for (int x = 0; x < newWidth; ++x) {
				cells.push_back(TableCell{});
			}
			continue;
		}

		for (int x = 0; x < newWidth; ++x) {
			if (x >= tableWidth) {
				cells.push_back(TableCell{});
			} else {
				auto& cell = GetCell({ x, y });
				cells.push_back(std::move(cell));
			}
		}
	}

	mCells = std::move(cells);
	mColumnWidths.resize(newWidth, 80);
	mRowHeights.resize(newHeight, 20);
}

int TableTemplate::GetRowHeight(int row) const
{
	return mRowHeights[row];
}

void TableTemplate::SetRowHeight(int row, int height)
{
	mRowHeights[row] = height;
}

int TableTemplate::GetColumnWidth(int column) const
{
	return mColumnWidths[column];
}

void TableTemplate::SetColumnWidth(int column, int width)
{
	mColumnWidths[column] = width;
}

const TableCell& TableTemplate::GetCell(Vec2i pos) const
{
	int tableWidth = GetTableWidth();
	return mCells[pos.y * tableWidth + pos.x];
}

TableCell& TableTemplate::GetCell(Vec2i pos)
{
	return const_cast<TableCell&>(const_cast<const TableTemplate*>(this)->GetCell(pos));
}

void TableTemplate::SetCellType(Vec2i pos, TableCell::CellType type)
{
	auto& cell = GetCell(pos);
	if (cell.Type == type) {
		return;
	}

	switch (cell.Type) {
		// Nothing to change
		case TableCell::ConstantCell: break;

		case TableCell::SingularParametricCell:
			mName2Parameters.erase(cell.Content);
			break;

		case TableCell::ArrayParametricCell: {
			auto& ag = mArrayGroups[cell.DataId];
			if (cell.Location.x == ag.LeftCell) {
				ag.LeftCell++;
			} else if (cell.Location.x == ag.RightCell) {
				ag.RightCell--;
			} else {

			}
		} break;
	}

	switch (type) {
		// Nothing to do
		case TableCell::ConstantCell: break;

		case TableCell::SingularParametricCell: {
			int idx = pos.y * GetTableWidth() + pos.x;
			auto [DISCARD, inserted] = mName2Parameters.emplace(cell.Content, idx);

			// Duplicate name
			if (!inserted) {
				return;
			}
		} break;

		case TableCell::ArrayParametricCell: {
			auto ptr = AddArrayGroup(pos.y, pos.x, pos.x);

			// Duplicate name
			if (ptr == nullptr) {
				return;
			}
		} break;
	}

	cell.Type = type;
}

int TableTemplate::GetArrayGroupCount() const
{
	return mArrayGroups.size();
}

const TableArrayGroup& TableTemplate::GetArrayGroup(int id) const
{
	return mArrayGroups[id];
}

TableArrayGroup& TableTemplate::GetArrayGroup(int id)
{
	return mArrayGroups[id];
}

TableArrayGroup* TableTemplate::AddArrayGroup(int row, int left, int right)
{
	// size_t max value: 18446744073709551615
	//                   ^~~~~~~~~~~~~~~~~~~~ 20 chars
	char name[20];
	auto res = std::to_chars(std::begin(name), std::end(name), mArrayGroups.size());
	std::string_view nameStr(name, res.ptr - name);

	return AddArrayGroup(nameStr, row, left, right);
}

TableArrayGroup* TableTemplate::AddArrayGroup(std::string_view name, int row, int left, int right)
{
	assert(row >= 0 && row < GetTableHeight());
	assert(left >= 0 && left < GetTableWidth());
	assert(right >= 0 && right < GetTableWidth());

	// TODO check for overlap

	if (left > right) {
		std::swap(left, right);
	}

	auto [DISCARD, inserted] = mName2ArrayGroups.emplace(name, (int)mArrayGroups.size());
	if (!inserted) {
		return nullptr;
	}

	mArrayGroups.push_back(TableArrayGroup{
		.Row = row,
		.LeftCell = left,
		.RightCell = right,
	});
	return &mArrayGroups.back();
}

bool TableTemplate::ExtendArrayGroupLeft(int id, int n)
{
	assert(n > 0);

	auto& ag = mArrayGroups[id];
	ag.LeftCell -= n;

	return false;
}

bool TableTemplate::ExtendArrayGroupRight(int id, int n)
{
	assert(n > 0);

	auto& ag = mArrayGroups[id];
	ag.RightCell += n;

	return false;
}

TableCell* TableTemplate::FindCell(std::string_view name)
{
	auto iter = mName2Parameters.find(name);
	if (iter != mName2Parameters.end()) {
		return &mCells[iter.value()];
	} else {
		return nullptr;
	}
}

TableArrayGroup* TableTemplate::FindArrayGroup(std::string_view name)
{
	auto iter = mName2ArrayGroups.find(name);
	if (iter != mName2ArrayGroups.end()) {
		return &mArrayGroups[iter.value()];
	} else {
		return nullptr;
	}
}

TableTemplate::MergeCellsResult TableTemplate::MergeCells(Vec2i topLeft, Vec2i bottomRight)
{
	auto SortTwo = [](int& a, int& b) {
		if (a > b) {
			std::swap(a, b);
		}
	};
	SortTwo(topLeft.x, bottomRight.x);
	SortTwo(topLeft.y, bottomRight.y);

	auto ResetProgress = [&]() {
		for (int y = topLeft.y; y < bottomRight.y; ++y) {
			for (int x = topLeft.x; x < bottomRight.x; ++x) {
				auto& cell = GetCell({ x, y });
				cell.PrimaryCellLocation = { -1, -1 };
			}
		}
	};

	for (int y = topLeft.y; y < bottomRight.y; ++y) {
		for (int x = topLeft.x; x < bottomRight.x; ++x) {
			auto& cell = GetCell({ x, y });
			if (cell.IsMergedCell()) {
				ResetProgress();
				return MCR_CellAlreadyMerged;
			}

			cell.PrimaryCellLocation = topLeft;
		}
	}

	auto& primaryCell = GetCell(topLeft);
	primaryCell.SpanX = bottomRight.x - topLeft.x;
	primaryCell.SpanY = bottomRight.y - topLeft.y;

	return MCR_Success;
}

TableTemplate::BreakCellsResult TableTemplate::BreakCells(Vec2i topLeft)
{
	auto& primaryCell = GetCell(topLeft);
	if (!primaryCell.IsMergedCell()) {
		return BCR_CellNotMerged;
	}

	for (int dy = 0; dy < primaryCell.SpanY; ++dy) {
		for (int dx = 0; dx < primaryCell.SpanX; ++dx) {
			auto& cell = GetCell({ topLeft.x + dx, topLeft.y + dy });
			cell.PrimaryCellLocation = { -1, -1 };
		}
	}

	primaryCell.SpanX = 1;
	primaryCell.SpanY = 1;

	return BCR_Success;
}

lxw_workbook* TableTemplate::InstantiateToExcelWorkbook(const TableInstantiationParameters& params) const
{
	auto workbook = workbook_new("Table.xlsx");
	InstantiateToExcelWorksheet(workbook, params);
	return workbook;
}

lxw_worksheet* TableTemplate::InstantiateToExcelWorksheet(lxw_workbook* workbook, const TableInstantiationParameters& params) const
{
	auto worksheet = workbook_add_worksheet(workbook, "CpltExport.xlsx");

	// Map: row number -> length of generated ranges
	std::map<int, int> generatedRanges;

	for (size_t i = 0; i < mArrayGroups.size(); ++i) {
		auto& info = mArrayGroups[i];
		auto& param = params.ArrayGroups[i];

		auto iter = generatedRanges.find(i);
		if (iter != generatedRanges.end()) {
			int available = iter->second;
			if (available >= param.size()) {
				// Current space is enough to fit in this array group, skip
				continue;
			}
		}

		// Not enough space to fit in this array group, update (or insert) the appropriate amount of generated rows
		int row = i;
		int count = param.size();
		generatedRanges.try_emplace(row, count);
	}

	auto GetOffset = [&](int y) -> int {
		// std::find_if <values less than y>
		int verticalOffset = 0;
		for (auto it = generatedRanges.begin(); it != generatedRanges.end() && it->first < y; ++it) {
			verticalOffset += it->second;
		}
		return verticalOffset;
	};

	auto WriteCell = [&](int row, int col, const TableCell& cell, const char* text) -> void {
		if (cell.IsPrimaryCell()) {
			int lastRow = row + cell.SpanY - 1;
			int lastCol = col + cell.SpanX - 1;
			// When both `string` and `format` are null, the top-left cell contents are untouched (what we just wrote in the above switch)
			worksheet_merge_range(worksheet, row, col, lastRow, lastCol, text, nullptr);
		} else {
			worksheet_write_string(worksheet, row, col, text, nullptr);
		}
	};

	// Write/instantiate all array groups
	for (size_t i = 0; i < mArrayGroups.size(); ++i) {
		auto& groupInfo = mArrayGroups[i];
		auto& groupParams = params.ArrayGroups[i];

		int rowCellCount = groupInfo.GetCount();
		int rowCount = groupParams.size();
		int baseRowIdx = groupInfo.Row + GetOffset(groupInfo.Row);

		// For each row that would be generated
		for (int rowIdx = 0; rowIdx < rowCount; ++rowIdx) {
			auto& row = groupParams[rowIdx];

			// For each cell in the row
			for (int rowCellIdx = 0; rowCellIdx < rowCellCount; ++rowCellIdx) {
				// TODO support merged cells in array groups
				worksheet_write_string(worksheet, baseRowIdx + rowIdx, rowCellIdx, row[rowCellIdx].c_str(), nullptr);
			}
		}
	}

	int tableWidth = GetTableWidth();
	int tableHeight = GetTableHeight();

	// Write all regular and singular parameter cells
	for (int y = 0; y < tableHeight; ++y) {
		for (int x = 0; x < tableWidth; ++x) {
			auto& cell = GetCell({ x, y });

			if (!cell.IsDataHoldingCell()) {
				continue;
			}

			switch (cell.Type) {
				case TableCell::ConstantCell: {
					int row = y + GetOffset(y);
					int col = x;

					WriteCell(row, col, cell, cell.Content.c_str());
				} break;

				case TableCell::SingularParametricCell: {
					int row = y + GetOffset(y);
					int col = x;

					auto iter = params.SingularCells.find({ x, y });
					if (iter != params.SingularCells.end()) {
						WriteCell(row, col, cell, iter.value().c_str());
					}
				} break;

				// See loop above that processes whole array groups at the same time
				case TableCell::ArrayParametricCell: break;
			}
		}
	}

	return worksheet;
}
Template::ReadResult TableTemplate::ReadFrom(std::istream& stream)
{
	// TODO
	return ReadResult::RR_Success;
}

void TableTemplate::WriteTo(std::ostream& stream) const
{
	// TODO
}