#include <stdio.h>
#include <string.h>

import Core.Terminal;
import Core.TerminalConstants;
import Core.List;
import Core.Math;
import Core.ToString;
import Core.Logger;

using SizeVector = Core::Vector<2, size_t>;

struct Cell {
    Core::String<16> content{};
};

static bool running = true;
static SizeVector size = {20, 10};
static Core::List<Cell> cells;
static SizeVector cursorPosition{0, 0};

static void init() {
    cells.resize(size[0] * size[1]);
    for(Cell& c : cells) {
        c.content.format(" ");
    }
}

static Cell& getCell(size_t x, size_t y) {
    return cells[y * size[0] + x];
}

static Cell& getCell(const SizeVector& v) {
    return getCell(v[0], v[1]);
}

static void print(const char* s) {
    fputs(s, stdout);
}

static size_t getColumnWidth(size_t x) {
    size_t w = 0;
    for(size_t y = 0; y < size[1]; y++) {
        Cell& c = getCell(x, y);
        w = Core::max(w, strlen(c.content));
    }
    return w;
}

static void render() {
    static constexpr const char* lc[2] = {
        Core::Terminal::BG_WHITE, Core::Terminal::BG_BRIGHT_WHITE};
    Core::clearTerminal();
    Core::resetCursor();
    Core::List<size_t> columnWidths;
    for(size_t x = 0; x < size[0]; x++) {
        columnWidths.add(getColumnWidth(x));
    }
    for(size_t y = 0; y < size[1]; y++) {
        print(lc[y & 1]);
        print("|");
        for(size_t x = 0; x < size[0]; x++) {
            Cell& c = getCell(x, y);
            if(cursorPosition[0] == x && cursorPosition[1] == y) {
                fputs(Core::Terminal::BG_BRIGHT_BLUE, stdout);
            }
            c.content.print();
            size_t filler = columnWidths[x] - strlen(c.content);
            while(filler > 0) {
                filler--;
                putchar(' ');
            }
            if(cursorPosition[0] == x && cursorPosition[1] == y) {
                fputs(lc[y & 1], stdout);
            }
            print("|");
        }
        putchar('\n');
    }
    fputs(Core::Terminal::RESET, stdout);
}

static void loop(u64 input) {
    // Core::IntVector2 size = Core::getTerminalSize();
    if(input == 'q') {
        running = false;
        return;
    } else if(input == Core::Terminal::KEY_ARROW_LEFT) {
        if(cursorPosition[0] > 0) {
            cursorPosition += SizeVector{-1, 0};
        }
    } else if(input == Core::Terminal::KEY_ARROW_RIGHT) {
        if(cursorPosition[0] < size[0] - 1) {
            cursorPosition += SizeVector{1, 0};
        }
    } else if(input == Core::Terminal::KEY_ARROW_UP) {
        if(cursorPosition[1] > 0) {
            cursorPosition += SizeVector{0, -1};
        }
    } else if(input == Core::Terminal::KEY_ARROW_DOWN) {
        if(cursorPosition[1] < size[1] - 1) {
            cursorPosition += SizeVector{0, 1};
        }
    } else {
        Cell& c = getCell(cursorPosition);
        c.content.add(static_cast<char>(input));
    }
    render();
}

int main() {
    Core::enterAlternativeTerminal();
    if(Core::enterRawTerminal()) {
        return 0;
    }
    init();
    render();
    while(running) {
        u64 u = Core::getRawChar();
        if(u != 0) {
            loop(u);
        }
    }
    if(Core::leaveRawTerminal()) {
        puts("Could not reset terminal.");
    }
    Core::leaveAlternativeTerminal();
    return 0;
}