//
//  main.c
//  HW3
//
//  Created by Muhammad Hleihel on 5/1/15.
//  Copyright (c) 2015 Muhammad Hleihel. All rights reserved.
//

#include <stdio.h>

void InitiateGame();
void PrintBoard(char Board[6][7]);
void InitiateBoard(char Board[6][7]);
void PrintTurn(char turn);
void StartGame(char Board[6][7]);
int ScanMove(char Board[6][7], char turn, int MovesArr[42], int *MovesCnt);
int CheckMove(char Board[6][7], char turn, int move, int MovesArr[42], int *MovesCnt);
int InRange(int move);
int IsFull(char Board[6][7], int column, char turn);
int EmptyCell(char Board[6][7], int column);
void Undo(char Board[6][7], int MovesArr[42], int *MovesCnt);
int Last_Move(char Board[6][7], int MovesArr[42], int *MovesCnt);
char CheckWin(char Board[6][7]);
char CheckWin_Vertical(char Board[6][7]);
char CheckWin_RDiagonal(char Board[6][7]);
char CheckWin_DDiagonal(char Board[6][7]);

int main()
{
    InitiateGame();
    return 0;
}

void InitiateGame()
{
    char Board[6][7];;
    printf("Welcome to Connect-4!\n\n");
    InitiateBoard(Board);
    PrintBoard(Board);
    StartGame(Board);
}

void StartGame(char Board[6][7])
{
    char last_turn = 'o';
    int MovesArr[43] = {0};
    int MovesCnt = 0;
    int tmp = 0;
    while(1)
    {
        if(MovesCnt == 42)
        {
            printf("The game has ended! It's a tie.");
            break;
        }
        PrintTurn((last_turn == 'o')?('*'):('o'));
        tmp = ScanMove(Board, (last_turn == 'o')?('*'):('o'), MovesArr, &MovesCnt);
        if(!tmp)
        {
            printf("You should have entered a number! We are doomed...");
            break;
        }
        else if(tmp == '*' || tmp == 'o')
        {
            printf("The game has ended! Player %c has won!!!!!", tmp);
            break;
        }
        last_turn = (last_turn == 'o')?('*'):('o');
    }
}

int InRange(int move)
{
    return (move >= 0 && move <= 7)?1:0;
}

int ScanMove(char Board[6][7], char turn, int MovesArr[42], int *MovesCnt)
{
    int move;
    if(scanf("%d", &move) != 1)
    {
        return 0;
    }
    CheckMove(Board, turn, move-1, MovesArr, MovesCnt);
    char win = CheckWin(Board);
    if(win == '*' || win == 'o') return win;
    return 1;
}


char CheckWin(char Board[6][7])
{
    char tmp = CheckWin_Vertical(Board);
    if(tmp != 0) return tmp;
    tmp = CheckWin_RDiagonal(Board);
    if(tmp != 0) return tmp;
    return CheckWin_DDiagonal(Board);
}

char CheckWin_Vertical(char Board[6][7])
{
    int s_count = 0;
    int o_count = 0;
    for(int i = 0; i < 7; i++)
    {
        for(int j = 0; j < 3; j++)
        {
            for(int k = 0; k <= 3; k++)
            {
                if(Board[j+k][i] == '*') s_count ++;
                if(Board[j+k][i] == 'o') o_count ++;
                if(s_count == 4) return Board[j+k][i];
                if(o_count == 4) return Board[j+k][i];
            }
            s_count = 0;
            o_count = 0;
        }
    }
    return 0;
}

char CheckWin_RDiagonal(char Board[6][7])
{
    int s_count = 0;
    int o_count = 0;
    for(int i = 0; i < 4; i++)
    {
        for(int j = 5; j >= 3; j--)
        {
            for(int k = 0; k <= 3; k++)
            {
                if(Board[j-k][i+k] == '*') s_count ++;
                if(Board[j-k][i+k] == 'o') o_count ++;
                if(s_count == 4 || o_count == 4) return Board[j-k][k+i];
            }
            s_count = 0;
            o_count = 0;
        }
    }
    return 0;
}

char CheckWin_DDiagonal(char Board[6][7])
{
    int s_count = 0;
    int o_count = 0;
    for(int i = 0; i < 4; i++)
    {
        for(int j = 0; j <= 2; j++)
        {
            for(int k = 0; k <= 3; k++)
            {
                if(Board[j+k][i+k] == '*') s_count ++;
                if(Board[j+k][i+k] == 'o') o_count ++;
                if(s_count == 4 || o_count == 4) return Board[j+k][k+i];
            }
            s_count = 0;
            o_count = 0;
        }
    }
    return 0;
}

void Undo(char Board[6][7], int MovesArr[42], int *MovesCnt)
{
    if(*MovesCnt > 0)
    {
        Board[Last_Move(Board, MovesArr, MovesCnt)][MovesArr[*MovesCnt]] = ' ';
        --*MovesCnt;
    }
}

int Last_Move(char Board[6][7], int MovesArr[42], int *MovesCnt)
{
    int last = 0;
    for(int i = 0; i < 6; ++i)
    {
        if(Board[i][MovesArr[*MovesCnt]] != ' ')
        {
            last = i;
            break;
        }
    }
    return last;
}

int CheckMove(char Board[6][7], char turn, int move, int MovesArr[42], int *MovesCnt)
{
    if(!(move+1))
    {
        Undo(Board, MovesArr, MovesCnt);
    }
    else
    {
        if(!InRange(move+1))
        {
            printf("Invalid move. Input move is out of range.\nPlease try again:");
            ScanMove(Board, turn, MovesArr, MovesCnt);
            return 0;
        }
        if(IsFull(Board, move, turn) == 1)
        {
            printf("Invalid move. Column %d is full.\nPlease try again:", move+1);
            ScanMove(Board, turn, MovesArr, MovesCnt);
            return 0;
        }
        Board[EmptyCell(Board, move)][move] = turn;
        MovesArr[++*MovesCnt] = move;
    }
    PrintBoard(Board);
    return 1;
}

int EmptyCell(char Board[6][7], int column)
{
    int count = 0;
    for(int i = 0; i < 6; i++)
    {
        if(Board[i][column] != ' ') count ++;
    }
    return (5-count);
}

int IsFull(char Board[6][7], int column, char turn)
{
    int count = 0;
    for(int i = 0; i < 6; i++)
    {
        if(Board[i][column] != ' ') count ++;
    }
    return (!(6-count)) ? 1 : 0;
}

void InitiateBoard(char Board[6][7])
{
    for(int i = 0; i < 6; i++)
        for(int j = 0; j < 7; j++)
            Board[i][j] = ' ';
}

void PrintBoard(char Board[6][7])
{
    for(int i = 0; i < 6; ++i)
    {
        printf("|");
        for(int j = 0; j < 7; ++j)
        {
            printf("%c|", Board[i][j]);
        }
        printf("\n");
    }
    printf("---------------\n ");
    for(int i = 0; i < 7; i++)
        printf("%c ", '1'+i);
    printf("\n");
}

void PrintTurn(char turn)
{
    printf("Player %c, in which column would you like to place your token? (enter 0 to undo)\n", turn);
}