#include <stdlib.h>
#include <stdbool.h>
#include <time.h>
#include <locale.h>
#include <ncurses.h>
#include "pieces.h"
#include "ui.h"

void clearmap(char** map, int mapH, int mapW) {
    for (int r = 0; r < mapH; r++) {
        for (int c = 0; c < mapW; c++) {
            map[r][c] = ' ';
        }
    }
}

int clearfull(char** map, int mapH, int mapW) {
    // if a row or column is full, clear it
    // if a row and a column are full at the same time, clear both
    // which is why we need to scan all rows/columns before actually clearing them
    // returns total number of blocks cleared
    bool* rows_to_clear = malloc(mapH * sizeof(bool));
    bool* cols_to_clear = malloc(mapW * sizeof(bool));
    int rtc_count = 0;
    int ctc_count = 0;
    // scan all rows and columns
    for (int r = 0; r < mapH; r++) {
        bool clear = true;
        for (int c = 0; c < mapW; c++) {
            if (map[r][c] == ' ')
                clear = false;
        }
        rows_to_clear[r] = clear;
    }
    for (int c = 0; c < mapW; c++) {
        bool clear = true;
        for (int r = 0; r < mapH; r++) {
            if (map[r][c] == ' ')
                clear = false;
        }
        cols_to_clear[c] = clear;
    }
    // clear rows and columns marked true in `{rows,columns}_to_clear`
    for (int r = 0; r < mapH; r++) {
        if (rows_to_clear[r]) {
            rtc_count++;
            for (int c = 0; c < mapW; c++)
                map[r][c] = ' ';
        }
    }
    for (int c = 0; c < mapW; c++) {
        if (cols_to_clear[c]) {
            ctc_count++;
            for (int r = 0; r < mapW; r++)
                map[r][c] = ' ';
        }
    }
    free(rows_to_clear);
    free(cols_to_clear);
    return (rtc_count * mapW + ctc_count * mapH - rtc_count * ctc_count);
}

void sirtet() {
    const int H = 8; // canvas height
    const int W = 8; // canvas width
    const int P = 3; // maximum # of pieces at hand

    // init memory and game state
    char** map = malloc(H * sizeof(char*));
    for (int r = 0; r < H; r++) {
        map[r] = malloc(W * sizeof(char));
    }
    struct piece** hand = malloc(P * sizeof(struct piece*));
    srand(time(NULL));
    clearmap(map, H, W);
    refillpieces(hand, P);

    bool over = false;
    int points = 0;

    // initialize ncurses
    setlocale(LC_ALL, "");
    initscr();
    clear();
    noecho();
    cbreak();
    keypad(stdscr, true);
    curs_set(0); // set cursor invisible
    start_color();
    init_pair(1, COLOR_GREEN, COLOR_BLACK);
    init_pair(2, COLOR_RED, COLOR_BLACK);

    // begin game loop
    while (!over) {
        clear();
        printrect(0, 0, H, W);
        printmap(map, 1, 1, H, W);

        // display game stats
        mvprintw(1, 2 * W + 8, "Points: %d", points);
        refresh();

        // select piece and position
        bool confirmed = false;

        int pc_idx;
        struct piece* pc;
        for (int i = 0; i < P; i++) {
            // find first non-null piece
            if (hand[i] != NULL) {
                pc_idx = i;
                pc = hand[i];
                break;
            }
        }

        int row = 0;
        int col = 0;

        while (!confirmed) {
            printmap(map, 1, 1, H, W);
            printpieces(hand, H + 2, 0, P, pc_idx);
            bool pos_placeable = placeable(map, pc, row, col, H, W);
            printpiece(pc, row + 1, col * 2 + 1, (pos_placeable ? 1 : 2));

            // await user input
            int ch = getch();
            switch (ch) {
                // enter: confirm choice
                case 10:
                    if (pos_placeable)
                        confirmed = true;
                    break;
                // arrow keys: move piece on map
                case KEY_LEFT:
                    if (col > 0) col--;
                    break;
                case KEY_RIGHT:
                    if (col + pc->w < W) col++;
                    break;
                case KEY_UP:
                    if (row > 0) row--;
                    break;
                case KEY_DOWN:
                    if (row + pc->h < H) row++;
                    break;
                // [ and ]: switch pieces
                case '[':
                    for (int i = 0; i < P; i++) {
                        // find previous non-null piece
                        pc_idx = (pc_idx + P - 1) % P;
                        if (hand[pc_idx] != NULL) {
                            pc = hand[pc_idx];
                            break;
                        }
                    }
                    break;
                case ']':
                    for (int i = 0; i < P; i++) {
                        // find next non-null piece
                        pc_idx = (pc_idx + 1) % P;
                        if (hand[pc_idx] != NULL) {
                            pc = hand[pc_idx];
                            break;
                        }
                    }
                    break;
            }
        }

        place(map, pc, row, col);
        points += pc->points;
        freepiece(pc);
        hand[pc_idx] = NULL;

        // clear full rows and columns
        int blocks_cleared = clearfull(map, H, W);
        points += blocks_cleared;

        // if player has no piece left, refill
        bool pieces_left = false;
        for (int i = 0; i < P; i++) {
            if (hand[i] != NULL) {
                pieces_left = true;
                break;
            }
        }
        if (!pieces_left)
            refillpieces(hand, P);

        // game over if none of the pieces are placeable
        bool has_placeable = false;
        for (int i = 0; i < P; i++) {
            if (hand[i] == NULL)
                continue;

            for (int r = 0; r <= H - hand[i]->h; r++) {
                for (int c = 0; c <= W - hand[i]->w; c++) {
                    if (placeable(map, hand[i], r, c, H, W))
                        has_placeable = true;
                }
            }
        }
        if (!has_placeable) {
            // game over
            mvprintw(3, 2 * W + 8, "Game over");
            mvprintw(4, 2 * W + 8, "Press any key to exit");
            refresh();
            while (getch() == 0);
            over = true;
        }
    }

    // free memory
    for (int r = 0; r < H; r++) {
        free(map[r]);
    }
    free(map);
    for (int i = 0; i < P; i++) {
        if (hand[i] != NULL)
            freepiece(hand[i]);
    }
    free(hand);

    // end ncurses
    endwin();
}

int main(int argc, char *argv[]) {
    sirtet();
    return 0;
}