#include <iostream>
#include "important.h"
#include <cstdint>
#include <chrono>
#include <fstream>

using namespace std;

float *S1_smoothen(struct image_t *input_image)
{
	int width = input_image->width;
	int height = input_image->height;

	// memory allocation
	float *smoother = (float *)malloc(height * width * 3 * sizeof(float));
	long ind = 0;

	for (int i = 0; i < height; i++)
	{
		for (int j = 0; j < width; j++)
		{
			for (int k = 0; k < 3; k++)
			{
				//  edge cases
				if (i == 0 && j == 0)
				{ // i-1 and j - 1 doesnt exist
					smoother[ind] = (float)(input_image->image_pixels[i][j][k] / 4 + input_image->image_pixels[i][j + 1][k] / 4 + input_image->image_pixels[i + 1][j][k] / 4 + input_image->image_pixels[i + 1][j + 1][k] / 4);
				}
				else if (i == height - 1 && j == 0)
				{ // i+1 and j-1 does not exist
					smoother[ind] = (float)(input_image->image_pixels[i - 1][j][k] / 4 + input_image->image_pixels[i - 1][j + 1][k] / 4 + input_image->image_pixels[i][j][k] / 4 + input_image->image_pixels[i][j + 1][k] / 4);
				}

				else if (i == 0 && j == width - 1)
				{ // i-1 and j+1 does not exist
					smoother[ind] = (float)(input_image->image_pixels[i][j - 1][k] / 4 + input_image->image_pixels[i][j][k] / 4 + input_image->image_pixels[i + 1][j - 1][k] / 4 + input_image->image_pixels[i + 1][j][k] / 4);
				}
				else if (i == height - 1 && j == width - 1)
				{ // i+1 and j+1 does not exist
					smoother[ind] = (float)(input_image->image_pixels[i - 1][j - 1][k] / 4 + input_image->image_pixels[i - 1][j][k] / 4 + input_image->image_pixels[i][j - 1][k] / 4 + input_image->image_pixels[i][j][k] / 4);
				}
				else if (i == 0)
				{ // i - 1 does not exist
					smoother[ind] = (float)(input_image->image_pixels[i][j - 1][k] / 6 + input_image->image_pixels[i][j][k] / 6 + input_image->image_pixels[i][j + 1][k] / 6 + input_image->image_pixels[i + 1][j - 1][k] / 6 + input_image->image_pixels[i + 1][j][k] / 6 + input_image->image_pixels[i + 1][j + 1][k] / 6);
				}

				else if (j == 0)
				{ // j -1 does not exist
					smoother[ind] = (float)(input_image->image_pixels[i - 1][j][k] / 6 + input_image->image_pixels[i - 1][j + 1][k] / 6 + input_image->image_pixels[i][j][k] / 6 + input_image->image_pixels[i][j + 1][k] / 6 + input_image->image_pixels[i + 1][j][k] / 6 + input_image->image_pixels[i + 1][j + 1][k] / 6);
				}

				else if (i == height - 1)
				{ // i+1 does not exist
					smoother[ind] = (float)(input_image->image_pixels[i - 1][j - 1][k] / 6 + input_image->image_pixels[i - 1][j][k] / 6 + input_image->image_pixels[i - 1][j + 1][k] / 6 + input_image->image_pixels[i][j - 1][k] / 6 + input_image->image_pixels[i][j][k] / 6 + input_image->image_pixels[i][j + 1][k] / 6);
				}
				else if (j == width - 1)
				{ // j + 1 does not exist
					smoother[ind] = (float)(input_image->image_pixels[i - 1][j - 1][k] / 6 + input_image->image_pixels[i - 1][j][k] / 6 + input_image->image_pixels[i][j - 1][k] / 6 + input_image->image_pixels[i][j][k] / 6 + input_image->image_pixels[i + 1][j - 1][k] / 6 + input_image->image_pixels[i + 1][j][k] / 6);
				}
				else
				{
					smoother[ind] = (float)(input_image->image_pixels[i - 1][j - 1][k] / 9 + input_image->image_pixels[i - 1][j][k] / 9 + input_image->image_pixels[i - 1][j + 1][k] / 9 + input_image->image_pixels[i][j - 1][k] / 9 + input_image->image_pixels[i][j][k] / 9 + input_image->image_pixels[i][j + 1][k] / 9 + input_image->image_pixels[i + 1][j - 1][k] / 9 + input_image->image_pixels[i + 1][j][k] / 9 + input_image->image_pixels[i + 1][j + 1][k] / 9);
				}
				ind++;
			}
		}
	}
	return smoother;
}

float *S2_find_details(struct image_t *input_image, float *smoothened_image)
{
	// TODO
	int width = input_image->width;
	int height = input_image->height;

	float *details = (float *)malloc(height * width * 3 * sizeof(float));
	long ind = 0;

	for (int i = 1; i < height - 1; i++)
	{
		for (int j = 1; j < width - 1; j++)
		{
			for (int k = 0; k < 3; k++)
			{
				details[ind] = max((float)0, (float)input_image->image_pixels[i][j][k] - smoothened_image[ind]);
				ind++;
			}
		}
	}

	return details;
}

float *S3_sharpen(struct image_t *input_image, float *details_image)
{
	// TODO
	int width = input_image->width;
	int height = input_image->height;

	float a = 0.8;

	float *sharp = (float *)malloc(height * width * 3 * sizeof(float));

	long ind = 0;
	for (int i = 1; i < height - 1; i++)
	{
		for (int j = 1; j < width - 1; j++)
		{
			for (int k = 0; k < 3; k++)
			{
				sharp[ind] = min((float)255, (float)input_image->image_pixels[i][j][k] + a * details_image[ind]);
				ind++;
			}
		}
	}
	return sharp; // TODO remove this line when adding your code
}

uint8_t skip_blanks_comments_while_reading(ifstream *read_stream) // returns the byte at the first position after the skipping of the blank space
{
	uint8_t val;
	while (true)
	{
		val = read_stream->get();
		if (val == '#')
		{
			while (val != '\n')
			{
				val = read_stream->get();
			}
		}
		if (val == '\n' || val == ' ' || val == '\t')
		{
			continue;
		}
		else if (val != '#')
			return val;
	}
	return val;
}

struct image_t *read_ppm_file(char *path_to_input_file)
{
	// cout << "input image file = " << path_to_input_file << "\n";

	ifstream read_stream(path_to_input_file, ios::binary | ios::in);

	if (read_stream.is_open())
	{
		struct image_t *image = new struct image_t;

		uint8_t val = skip_blanks_comments_while_reading(&read_stream); // 'P'
		val = read_stream.get();										//'6'

		// width
		val = skip_blanks_comments_while_reading(&read_stream);
		while (true)
		{
			if (val == ' ' || val == '\t' || val == '\n')
				break;
			image->width = image->width * 10 + (val - '0');
			val = read_stream.get();
		}
		// cout << "width = " << image->width << "\n";

		// height
		val = skip_blanks_comments_while_reading(&read_stream);
		while (true)
		{
			if (val == ' ' || val == '\t' || val == '\n')
				break;
			image->height = image->height * 10 + (val - '0');
			val = read_stream.get();
		}
		// cout << "height = " << image->height << "\n";

		image->image_pixels = new uint8_t **[image->height];
		for (int i = 0; i < image->height; i++)
		{
			image->image_pixels[i] = new uint8_t *[image->width];
			for (int j = 0; j < image->width; j++)
				image->image_pixels[i][j] = new uint8_t[3];
		}

		// maxval
		val = skip_blanks_comments_while_reading(&read_stream);
		while (true)
		{
			if (val == ' ' || val == '\t' || val == '\n')
				break;
			val = read_stream.get();
		}

		// get pixel values
		val = skip_blanks_comments_while_reading(&read_stream);
		for (int i = 0; i < image->height; i++)
		{
			for (int j = 0; j < image->width; j++)
			{
				for (int k = 0; k < 3; k++)
				{
					image->image_pixels[i][j][k] = val;
					val = read_stream.get(); // assuming maxval of <=255
				}
			}
		}
		// read_stream.seekg(-1, ios_base::cur);
		// read_stream.read(((char*)image->image_pixels), image->height * image->width * 3); //assuming maxval of <=255

		read_stream.close();

		return image;
	}
	else
	{
		cerr << "failed to open file " << path_to_input_file << "\n\n";
		exit(1);
	}
}

void write_ppm_file(char *path_to_output_file, struct image_t *image)
{
	// cout << "output image file = " << path_to_output_file << "\n";

	ofstream write_stream(path_to_output_file, ios::binary | ios::out);

	if (write_stream.is_open())
	{
		write_stream.write("P6\n", 3);
		std::string width_string = std::to_string(image->width);
		// cout << "width = " << width_string << "\n";
		write_stream.write(width_string.c_str(), width_string.length());
		write_stream.write(" ", 1);
		std::string height_string = std::to_string(image->height);
		// cout << "height = " << height_string << "\n";
		write_stream.write(height_string.c_str(), height_string.length());
		write_stream.write("\n255\n", 5);
		for (int i = 0; i < image->height; i++)
		{
			for (int j = 0; j < image->width; j++)
			{
				for (int k = 0; k < 3; k++)
				{
					write_stream.put(image->image_pixels[i][j][k]); // assuming maxval of <=255
				}
			}
		}
		// write_stream.write(((char*)image->image_pixels), image->height * image->width * 3);
		write_stream.close();
	}
	else
	{
		cerr << "failed to open file " << path_to_output_file << "\n\n";
		exit(1);
	}
}