#include <iostream>
/* #include <string_view> */
#include <string>
#include "tree.hpp"
#include "utils.hpp"

/* macro rather then function to avoid warnings */
#define UNEXPECTED_END() endwin(); cerr << "Unexpected end of file" << std::endl; exit(1)

using std::cerr;
/* using std::string_view; */
using std::string;
using std::vector;
using std::pair;

namespace /* internal */
{
	struct alloced
	{
		char* const data;
		char* const end;
		alloced(U32 len)
			: data(new char[len])
			, end(data + len)
		{
		}
		~alloced()
		{
			delete[] data;
		}
	};

	char* end_data;				/* past the end pointer */
	unsigned line = 1;
	pair<person_id, person_id> prev_parents(Nobody, Nobody);

	/* state */
	void state_neutral(char* it_data);
	void state_person(char*& it_data);
	/* void state_person_attribute() */

	/* result */
	Tree* cur_tree;

	bool isNum(char c)
	{
		return c >= '0' && c <= '9';
	}

	void unexpected_char(char c)
	{
		endwin();
		cerr << "Line " << line <<  ": Unexpected '" << c << std::endl;
		exit(1);
	}

	/* void unexpected_end() */
	/* { */
	/* 	endwin(); */
	/* 	cerr << "Unexpected end of file" << std::endl; */
	/* 	exit(1); */
	/* } */

	void proceedToNameEnd(char*& it_data)
	{
		while(it_data < end_data &&
			  *it_data != ',' &&
			  *it_data != '\n' &&
			  !isNum(*it_data))
		{
			if(*it_data == ':' /* && *it_data == '-' */)
				unexpected_char(*it_data);
			++it_data;
		}

	}

	U32 sameNamedIndex(char*& it_data)
	{
		U32 res = 0;
		if(isNum(*it_data))
		{
			res = *it_data - '0'; /* todo many digits */
			++it_data;
		}
		return res;
	}

	Sex findSex(char*& it_data)
	{
		Sex res = M;
		if(*it_data == ',')
		{
			++it_data;
			if(*it_data == 'M')
				res = M;
			else if(*it_data == 'F')
				res = F;
			else
				unexpected_char(*it_data);

			++it_data;
			if(*it_data != '\n')
				unexpected_char(*it_data);
		}
		return res;
	}

	I32 processDatePart(char*& it_data)
	{
		I32 sign = 1;
		I32 val = 0;
		for(; it_data < end_data; ++it_data)
		{
			switch(*it_data)
			{
			case '-':
				sign = -1;
				break;
			case '0' ... '9':
				val = val*10 + (*it_data - '0');
				break;
			case '.':
				if(val == 0)
					unexpected_char('.');
				else
					return sign * val;
				break;
			case '\n':
				++line;
				return sign * val;
				/* case '?': todo */
			default:
				unexpected_char(*it_data);
			}
		}
		UNEXPECTED_END();
	}

	EventTime processDate(char*& it_data)		/* todo validate  */
	{
		EventTime date;
		date.year = processDatePart(it_data);
		if(*it_data == '.')
		{
			++it_data;
			date.month = processDatePart(it_data);

			if(*it_data == '.')
			{
				++it_data;
				date.day = processDatePart(it_data);
			}
		}
		return date;
	}

	pair<person_id, person_id> processParents(char*& it_data)
	{
		pair<person_id, person_id> res(Nobody, Nobody);
		U32 same_name_index = 0;
		string name;			/* todo dont use string */
		for(; it_data < end_data; ++it_data)
		{
			switch(*it_data)
			{
			case ',':
				if(res.first == Nobody)
					res.first = cur_tree->findId(name.data())[same_name_index]; /* todo validate index */
				else if(res.second == Nobody)
					res.second = cur_tree->findId(name.data())[same_name_index];
				else
					/* todo */TFT_EXIT(1);
				same_name_index = 0;
				name.clear();
				break;
			case '-':
				if(name.empty() && res.first == Nobody)
					return prev_parents;
				else
					unexpected_char('-');
			case '\n':
				++line;
				if(res.first == Nobody)
					res.first = cur_tree->findId(name.data())[same_name_index];
				else
					res.second = cur_tree->findId(name.data())[same_name_index];
				return prev_parents = res;
			case '_':
				name.push_back(' ');
				break;
			case '0' ... '9':
				same_name_index = *it_data - '0';
				break;
			default:
				name.push_back(*it_data);
			}
		}
		UNEXPECTED_END();
	}

	vector<person_id> parseSpouses(char*& it_data)
	{
		vector<person_id> res;
		U32 same_name_index = 0;
		string name;
		for(; it_data < end_data; ++it_data)
		{
			switch(*it_data)
			{
			case '-':
				if(name.empty())
					res.push_back( cur_tree->last() );
				else
					unexpected_char('-');
				break;
			case ',':
				if(!name.empty())
				{
					res.push_back( cur_tree->findId(name.data())[same_name_index] );
					name.clear();
					same_name_index = 0;
				}
				else
					unexpected_char(',');
				break;
			case '\n':
				++line;
				if(!name.empty())
					res.push_back( cur_tree->findId(name.data())[same_name_index] );
				return res;
			case '_':
				name.push_back(' ');
				break;
			case '0' ... '9':
				same_name_index = *it_data - '0';
				break;
			default:
				name.push_back(*it_data);
			}
		}
		if(!name.empty())
			res.push_back( cur_tree->findId(name.data())[same_name_index] );
		return res;
	}

	void state_neutral(char* it_data)
	{
		for(; it_data < end_data; ++it_data)
		{
			switch(*it_data)
			{
			default:
				state_person(it_data);
				break;
			case '\n':
				++line;
				break;
			case ',':
			case '-':
			case 0 ... 9:
			case ':':
				unexpected_char(*it_data);
			}
		}
	}

	void state_person(char*& it_data)
	{
		char* name_start = it_data;
		pair<person_id, person_id> parents(Nobody, Nobody);
		vector<person_id> spouses;
		EventTime birth{};
		EventTime death{};

		proceedToNameEnd(it_data); /* todo merge funcs */
		string name(name_start, it_data);

		U32 same_name_index = sameNamedIndex(it_data);
		/* string_view name(name_start, it_data); */
		for(char& c: name)
		{
			if(c == '_')
				c = ' ';
		}



		Sex sex = findSex(it_data);

		for(; it_data < end_data; ++it_data)
		{
			switch(*it_data)
			{
			case '\n':
				++line;
				break;
			default:
				if(it_data[1] == ':') /* todo */
				{
					switch(*it_data)
					{
					case 'b':
						it_data += 2;
						birth = processDate(it_data);
						break;
					case 'd':
						it_data += 2;
						death = processDate(it_data);
						break;
					case 'p':
						it_data += 2;
						parents = processParents(it_data);
						break;
					case 's':
						it_data += 2;
						spouses = parseSpouses(it_data);
						break;
					default:
						unexpected_char(it_data[-1]);
					}

				}
				else
				{
					cur_tree->addPerson(name.c_str(), sex, parents.first, parents.second, birth, death);
					for(person_id spouse: spouses)
						cur_tree->addRelation(spouse, Spouse, cur_tree->last());
					--it_data;	/* rewind 1 */
					return;
				}
				break;
			/* case 0...9: */
			/* case ':': */
			/* 	unexpected_char(*it_data); */
			/* default: */
				/* break; */
			}
		}
		cur_tree->addPerson(name.c_str(), sex, parents.first, parents.second, birth, death);
		for(person_id spouse: spouses)
			cur_tree->addRelation(spouse, Spouse, cur_tree->last());
	}

	alloced preprocess(MappedFile file) /* remove whitespace and comments */
	{
		alloced res(file.len);

		char* itres = res.data;
		char* end = file.data + file.len;
		for(char* it = file.data; it < end; ++it)
		{
			switch(*it)
			{
			case '#':
				while(++it != end && *it != '\n'); /* skip comment */
				*itres++ = '\n';				   /* add \n */
				break;
			case ' ':
			case '\t':
			case '\r':
				break;
			default:
				*itres = *it;
				++itres;
			}
		}
		end_data = itres;
		return res;
	}

}


Tree parseTftFile(fd_t file)
{
	Tree result("t");
	cur_tree = &result;

	MappedFile mapedfile = mapfile(file);
	alloced preprocessed = preprocess(mapedfile);

	state_neutral(preprocessed.data);

	return result;
}