/*
  Copyright (c) 2022 Alex Diener
  
  This software is provided 'as-is', without any express or implied
  warranty. In no event will the authors be held liable for any damages
  arising from the use of this software.
  
  Permission is granted to anyone to use this software for any purpose,
  including commercial applications, and to alter it and redistribute it
  freely, subject to the following restrictions:
  
  1. The origin of this software must not be misrepresented; you must not
     claim that you wrote the original software. If you use this software
     in a product, an acknowledgment in the product documentation would be
     appreciated but is not required.
  2. Altered source versions must be plainly marked as such, and must not be
     misrepresented as being the original software.
  3. This notice may not be removed or altered from any source distribution.
  
  Alex Diener alex@ludobloom.com
*/

#include <limits.h>
#include "utilities/IndexSubindexSelection.h"

#define stemobject_implementation IndexSubindexSelection

stemobject_vtable_begin();
stemobject_vtable_entry(dispose);
stemobject_vtable_end();

IndexSubindexSelection * IndexSubindexSelection_create(void) {
	stemobject_create_implementation(init)
}

bool IndexSubindexSelection_init(IndexSubindexSelection * self) {
	call_super(init, self);
	self->pairCount = 0;
	self->private_ivar(pairAllocatedCount) = 0;
	self->pairs = NULL;
	self->reverseLookup = ReverseIndexLookup_create();
	self->selectionDirtyValue = 0;
	self->reverseLookupDirtyValue = 0;
	self->lastReverseLookupDirtyValue = UINT_MAX;
	return true;
}

void IndexSubindexSelection_dispose(IndexSubindexSelection * self) {
	ReverseIndexLookup_dispose(self->reverseLookup);
	free(self->pairs);
	call_super_virtual(dispose, self);
}

IndexSubindexSelection * IndexSubindexSelection_copy(IndexSubindexSelection * self) {
	IndexSubindexSelection * copy = IndexSubindexSelection_create();
	copy->private_ivar(pairAllocatedCount) = copy->pairCount = self->pairCount;
	if (copy->pairCount > 0) {
		copy->pairs = malloc(copy->pairCount * sizeof(*copy->pairs));
		memcpy(copy->pairs, self->pairs, copy->pairCount * sizeof(*copy->pairs));
	}
	return copy;
}

static void resizeAllocation(IndexSubindexSelection * self, unsigned int allocationCount) {
	if (self->private_ivar(pairAllocatedCount) <= allocationCount) {
		if (self->private_ivar(pairAllocatedCount) == 0) {
			self->private_ivar(pairAllocatedCount) = 16;
		}
		while (self->private_ivar(pairAllocatedCount) < allocationCount) {
			self->private_ivar(pairAllocatedCount) *= 2;
		}
		self->pairs = realloc(self->pairs, sizeof(*self->pairs) * self->private_ivar(pairAllocatedCount));
	}
}

void IndexSubindexSelection_copySelectionFrom(IndexSubindexSelection * self, IndexSubindexSelection * selection) {
	resizeAllocation(self, selection->pairCount);
	memcpy(self->pairs, selection->pairs, selection->pairCount * sizeof(*self->pairs));
	self->pairCount = selection->pairCount;
	self->lastReverseLookupDirtyValue = UINT_MAX;
}

bool IndexSubindexSelection_selectIndexPair(IndexSubindexSelection * self, unsigned int index, unsigned int subindex, bool assumeUnique) {
	if (!assumeUnique && IndexSubindexSelection_isPairSelected(self, index, subindex, NULL)) {
		return false;
	}
	resizeAllocation(self, self->pairCount + 1);
	self->pairs[self->pairCount].index = index;
	self->pairs[self->pairCount].subindex = subindex;
	ReverseIndexLookup_set(self->reverseLookup, index, self->pairCount);
	self->pairCount++;
	self->selectionDirtyValue++;
	return true;
}

bool IndexSubindexSelection_deselectIndexPair(IndexSubindexSelection * self, unsigned int index, unsigned int subindex) {
	for (unsigned int pairIndex = 0; pairIndex < self->pairCount; pairIndex++) {
		if (self->pairs[pairIndex].index == index && self->pairs[pairIndex].subindex == subindex) {
			self->pairCount--;
			for (; pairIndex < self->pairCount; pairIndex++) {
				self->pairs[pairIndex] = self->pairs[pairIndex + 1];
			}
			self->selectionDirtyValue++;
			self->reverseLookupDirtyValue++;
			return true;
		}
	}
	return false;
}

bool IndexSubindexSelection_deselectAll(IndexSubindexSelection * self) {
	bool anythingSelected = self->pairCount > 0;
	self->pairCount = 0;
	ReverseIndexLookup_empty(self->reverseLookup);
	return anythingSelected;
}

bool IndexSubindexSelection_toggleIndexPair(IndexSubindexSelection * self, unsigned int index, unsigned int subindex) {
	self->selectionDirtyValue++;
	for (unsigned int pairIndex = 0; pairIndex < self->pairCount; pairIndex++) {
		if (self->pairs[pairIndex].index == index && self->pairs[pairIndex].subindex == subindex) {
			self->pairCount--;
			for (; pairIndex < self->pairCount; pairIndex++) {
				self->pairs[pairIndex] = self->pairs[pairIndex + 1];
			}
			self->reverseLookupDirtyValue++;
			return false;
		}
	}
	resizeAllocation(self, self->pairCount + 1);
	self->pairs[self->pairCount].index = index;
	self->pairs[self->pairCount].subindex = subindex;
	ReverseIndexLookup_set(self->reverseLookup, index, self->pairCount);
	self->pairCount++;
	return true;
}

void IndexSubindexSelection_deselectItemAtIndex(IndexSubindexSelection * self, unsigned int pairIndex) {
	self->pairCount--;
	for (; pairIndex < self->pairCount; pairIndex++) {
		self->pairs[pairIndex] = self->pairs[pairIndex + 1];
	}
	self->selectionDirtyValue++;
	self->reverseLookupDirtyValue++;
}

static void updateReverseLookup(IndexSubindexSelection * self) {
	if (self->lastReverseLookupDirtyValue == self->reverseLookupDirtyValue) {
		return;
	}
	ReverseIndexLookup_empty(self->reverseLookup);
	for (unsigned int pairIndex = 0; pairIndex < self->pairCount; pairIndex++) {
		ReverseIndexLookup_set(self->reverseLookup, self->pairs[pairIndex].index, pairIndex);
	}
	self->lastReverseLookupDirtyValue = self->reverseLookupDirtyValue;
}

bool IndexSubindexSelection_isPairSelected(IndexSubindexSelection * self, unsigned int index, unsigned int subindex, unsigned int * outSelectionIndex) {
	updateReverseLookup(self);
	struct ReverseIndexLookup_entry * entry = ReverseIndexLookup_get(self->reverseLookup, index);
	if (entry != NULL) {
		unsigned int count = entry->count;
		unsigned int * values = entry->values;
		for (unsigned int valueIndex = 0; valueIndex < count; valueIndex++) {
			if (self->pairs[values[valueIndex]].subindex == subindex) {
				if (outSelectionIndex != NULL) {
					*outSelectionIndex = values[valueIndex];
				}
				return true;
			}
		}
	}
	return false;
}

void IndexSubindexSelection_adjustIndexes(IndexSubindexSelection * self, unsigned int indexStart, int indexDelta) {
	unsigned int offset = 0;
	bool adjusted = false;
	for (unsigned int pairIndex = 0; pairIndex < self->pairCount; pairIndex++) {
		self->pairs[pairIndex] = self->pairs[pairIndex + offset];
		if (self->pairs[pairIndex].index >= indexStart) {
			if (self->pairs[pairIndex].index < indexStart - indexDelta) {
				offset++;
				pairIndex--;
				self->pairCount--;
			} else {
				self->pairs[pairIndex].index += indexDelta;
			}
			adjusted = true;
		}
	}
	if (adjusted) {
		self->selectionDirtyValue++;
		self->reverseLookupDirtyValue++;
	}
}

void IndexSubindexSelection_adjustSubindexes(IndexSubindexSelection * self, unsigned int index, unsigned int subindexStart, int subindexDelta) {
	unsigned int offset = 0;
	bool adjusted = false;
	for (unsigned int pairIndex = 0; pairIndex < self->pairCount; pairIndex++) {
		self->pairs[pairIndex] = self->pairs[pairIndex + offset];
		if (self->pairs[pairIndex].index == index && self->pairs[pairIndex].subindex >= subindexStart) {
			if (self->pairs[pairIndex].subindex < subindexStart - subindexDelta) {
				offset++;
				pairIndex--;
				self->pairCount--;
			} else {
				self->pairs[pairIndex].subindex += subindexDelta;
			}
			adjusted = true;
		}
	}
	if (adjusted) {
		self->selectionDirtyValue++;
		self->reverseLookupDirtyValue++;
	}
}

bool IndexSubindexSelection_truncateSelectionToMaxIndexCount(IndexSubindexSelection * self, unsigned int maxIndexCount) {
	unsigned int offset = 0;
	for (unsigned int pairIndex = 0; pairIndex < self->pairCount; pairIndex++) {
		self->pairs[pairIndex] = self->pairs[pairIndex + offset];
		if (self->pairs[pairIndex].index >= maxIndexCount) {
			offset++;
			pairIndex--;
			self->pairCount--;
		}
	}
	if (offset > 0) {
		self->selectionDirtyValue++;
		self->reverseLookupDirtyValue++;
		return true;
	}
	return false;
}

unsigned int IndexSubindexSelection_removeDuplicates(IndexSubindexSelection * self) {
	unsigned int removedCount = 0;
	for (unsigned int pairIndex = 1; pairIndex < self->pairCount; pairIndex++) {
		self->pairs[pairIndex] = self->pairs[pairIndex + removedCount];
		for (unsigned int pairIndex2 = 0; pairIndex2 < pairIndex; pairIndex2++) {
			if (self->pairs[pairIndex].index == self->pairs[pairIndex2].index &&
			    self->pairs[pairIndex].subindex == self->pairs[pairIndex2].subindex) {
				removedCount++;
				pairIndex--;
				self->pairCount--;
				break;
			}
		}
	}
	if (removedCount > 0) {
		self->selectionDirtyValue++;
		self->reverseLookupDirtyValue++;
	}
	return removedCount;
}