#include <iostream>
#include <fstream>	//for ifstream, ofstream
#include <iterator>	//for ostream_iterator
#include <algorithm>	//for min, max, copy
#include <cstdlib>	//for system
#include <climits>	//for UCHAR_MAX
#include <cstring>	//for strcmp
#include <unistd.h>
#include "picture.h"

picture::picture(int gray)
{
	pixel p(gray, gray, gray);

	for (size_t row = 0; row < nrows; ++row) {
		for (size_t col = 0; col < ncols; ++col) {
			a[row][col] = p;
		}
	}
}

picture::picture(int red, int green, int blue)
{
	pixel p(red, green, blue);

	for (size_t row = 0; row < nrows; ++row) {
		for (size_t col = 0; col < ncols; ++col) {
			a[row][col] = p;
		}
	}
}

picture::picture(pixel p)
{
	for (size_t row = 0; row < nrows; ++row) {
		for (size_t col = 0; col < ncols; ++col) {
			a[row][col] = p;
		}
	}
}

picture::picture(pixel p[nrows][ncols])
{
	for (size_t row = 0; row < nrows; ++row) {
		for (size_t col = 0; col < ncols; ++col) {
			a[row][col] = p[row][col];
		}
	}
}

picture& picture::operator+=(const picture& another)
{
	for (size_t row = 0; row < nrows; ++row) {
		for (size_t col = 0; col < ncols; ++col) {
			a[row][col].red   += another.a[row][col].red;
			a[row][col].green += another.a[row][col].green;
			a[row][col].blue  += another.a[row][col].blue;
		}
	}

	return *this;
}

picture& picture::operator-=(const picture& another)
{
	for (size_t row = 0; row < nrows; ++row) {
		for (size_t col = 0; col < ncols; ++col) {
			a[row][col].red   -= another.a[row][col].red;
			a[row][col].green -= another.a[row][col].green;
			a[row][col].blue  -= another.a[row][col].blue;
		}
	}

	return *this;
}

picture& picture::operator*=(int factor)
{
	for (size_t row = 0; row < nrows; ++row) {
		for (size_t col = 0; col < ncols; ++col) {
			a[row][col].red *= factor;
			a[row][col].green *= factor;
			a[row][col].blue *= factor;
		}
	}

	return *this;
}

picture& picture::operator/=(int divisor)
{
	for (size_t row = 0; row < nrows; ++row) {
		for (size_t col = 0; col < ncols; ++col) {
			a[row][col].red /= divisor;
			a[row][col].green /= divisor;
			a[row][col].blue /= divisor;
		}
	}

	return *this;
}

picture& picture::operator&=(color c)
{
	for (size_t row = 0; row < nrows; ++row) {
		for (size_t col = 0; col < ncols; ++col) {
			pixel *const p = &a[row][col];
			switch (c) {
			case color_red:
				p->green = p->blue = 0;
				break;
			case color_green:
				p->red = p->blue = 0;
				break;
			case color_blue:
				p->red = p->green = 0;
				break;
			}
		}
	}

	return *this;
}

picture::picture(const char *filename)
{
	if (strlen(filename) >= 4
		&& strcmp(filename + strlen(filename) - 4, ".jpg") == 0) {
		char command[1024];
		const char *const tempfile = tmpnam(0);

		sprintf(command, "/opt/sfw/netpbm/bin/jpegtopnm %s | "
			"/opt/sfw/netpbm/bin/pnmtoplainpnm > %s",
			filename, tempfile);

		const int ret = system(command);
		if (ret < 0) {
			cerr << "constructor: system returned a negative number.\n";
		}

		ifstream ifstr(tempfile);
		if (!ifstr) {
			cerr << "couldn't open input file " << tempfile << "\n";
			exit(EXIT_FAILURE);
		}

		string format;
		int width, height, max;
		ifstr >> format >> width >> height >> max;

		for (size_t row = 0; row < height; ++row) {
			for (size_t col = 0; col < width; ++col) {
				unsigned red, green, blue;
				ifstr >> red >> green >> blue;
				if (row < nrows && col < ncols) {
					a[row][col].red = red;
					a[row][col].green = green;
					a[row][col].blue = blue;
				}
			}
		}

		ifstr.close();
		if (unlink(tempfile) != 0) {
			cerr << "unlink did not return 0\n";
		}
	}
}

inline int clamp(int i) {return max(0, min(UCHAR_MAX, i));}

ostream& operator<<(ostream& ost, const picture& p)
{
	char tempfile1[L_tmpnam];
	strcpy(tempfile1, tmpnam(0));
	ofstream ofstr(tempfile1);
	if (!ofstr) {
		cerr << "couldn't open output file " << tempfile1 << "\n";
		exit(EXIT_FAILURE);
	}

	ofstr << "P3\n"
		<< picture::ncols << " " << picture::nrows << "\n"
		<< UCHAR_MAX << "\n";

	for (size_t row = 0; row < picture::nrows; ++row) {
		for (size_t col = 0; col < picture::ncols; ++col) {
			const pixel pix = p.a[row][col];
			ofstr << clamp(pix.red) << "\t"
				<< clamp(pix.green) << "\t"
				<< clamp(pix.blue) << "\n";
		}
	}
	ofstr.close();

	char *tempfile2 = tmpnam(0);
	char command[1024];
	sprintf(command, "/opt/sfw/netpbm/bin/ppmtojpeg < %s > %s",
		tempfile1, tempfile2);

	const int ret = system(command);
	if (ret < 0) {
		cerr << "system returned a negative number.\n";
	}
	if (unlink(tempfile1) != 0) {
		cerr << "unlink did not return 0\n";
	}

	ifstream ifstr(tempfile2);
	ifstr >> noskipws;
	copy(
		istream_iterator<char>(ifstr),
		istream_iterator<char>(),
		ostream_iterator<char>(cout));
	
	ofstr.close();

	if (unlink(tempfile2) != 0) {
		cerr << "unlink did not return 0\n";
	}
	return ost;
}