// voxelThing.c
// A voxel chunk rendering doodad written in C with Raylib

// External libraries
#include "raylib.h"
#include "raymath.h"
#include "rlgl.h"
#include "stdio.h"

// Project files
#include "chunkStructures.h"
#include "chunkRenderer.h"
#include "blockTypes.h"
#include "playerController.h"
#include "chunkGenerator.h"

// Bunch of global variables to clean up later.
float cameraYaw = 0;
float cameraPitch = 0;
bool paused = false;
RaycastHit hit;
int blockSelection = BLOCK_SAND;

// Random helper function for returning what direction you're facing.'
const char* GetCompassDirection(float yaw) {
    yaw = fmodf(yaw * RAD2DEG + 360.0f, 360.0f);
    if (yaw < 22.5f || yaw >= 337.5f) return "South (+Z)";
    if (yaw < 67.5f)  return "Southwest (+X+Z)";
    if (yaw < 112.5f) return "West (+X)";
    if (yaw < 157.5f) return "Northwest (+X-Z)";
    if (yaw < 202.5f) return "North (-Z)";
    if (yaw < 247.5f) return "Northeast (-X-Z)";
    if (yaw < 292.5f) return "East (-X)";
    return "Southeast (-X+Z)";
}

// Another random helper function, this time for checking if a Vector3 is non-zero.
static inline bool Vector3IsNonZero(Vector3 v) {
    return v.x != 0.0f || v.y != 0.0f || v.z != 0.0f;
}

int main(void) {
    // --- Screen setup ---
    int screenWidth = 800;
    int screenHeight = 600;
    SetConfigFlags(FLAG_WINDOW_RESIZABLE);
    InitWindow(screenWidth, screenHeight, "VoxelThing");
    SetExitKey(-1);
    DisableCursor(); // Lock mouse to window for FPS-style camera

    // --- World generation ---
    Chunk chunk;
    GenerateFlatChunk(&chunk);
    PlaceTreeAt(&chunk, 8, 7, 8);
    Mesh chunkMesh = GenerateChunkMesh(&chunk);

    // --- Load textures and materials ---
    Texture2D atlas = LoadTexture("assets/TextureAtlas.png");
    Material mat = LoadMaterialDefault();
    mat.maps[MATERIAL_MAP_DIFFUSE].texture = atlas;

    // --- Initialize camera ---
    Camera3D camera = { 0 };
    camera.position = (Vector3){ 10.0f, 10.0f, 10.0f };  // Initial camera position
    camera.target = (Vector3){ 0.0f, 0.0f, 0.0f };            // Looking toward origin
    camera.up = (Vector3){ 0.0f, 1.0f, 0.0f };                  // Y-up world
    camera.fovy = 90.0f;                                                    // Field of view
    camera.projection = CAMERA_PERSPECTIVE;          // Use perspective projection

    SetTargetFPS(60);

    // --- Main game loop ---
    while (!WindowShouldClose()) {
        screenWidth = GetScreenWidth();
        screenHeight = GetScreenHeight();
        BeginDrawing();
        ClearBackground(RAYWHITE);

        // --- Handle jumping to fullscreen mode with F11 ---
        if (IsKeyPressed(KEY_F11)) {
            ToggleFullscreen();
            Vector2 center = { GetScreenWidth() / 2.0f, GetScreenHeight() / 2.0f };
            SetMousePosition(center.x, center.y);
        }

        // --- Handle pausing ---
        if (IsKeyPressed(KEY_ESCAPE)) {
            paused = !paused;
            if (paused) EnableCursor();
            else DisableCursor();
        }

        // --- Handle selecting blocks ---

        if (IsKeyPressed(KEY_ONE)) blockSelection = BLOCK_STONE;
        if (IsKeyPressed(KEY_TWO)) blockSelection = BLOCK_DIRT;
        if (IsKeyPressed(KEY_THREE)) blockSelection = BLOCK_GRASS;
        if (IsKeyPressed(KEY_FOUR)) blockSelection = BLOCK_SAND;
        if (IsKeyPressed(KEY_FIVE)) blockSelection = BLOCK_GRAVEL;
        if (IsKeyPressed(KEY_SIX)) blockSelection = BLOCK_LOG;
        if (IsKeyPressed(KEY_SEVEN)) blockSelection = BLOCK_LEAF;
        if (IsKeyPressed(KEY_EIGHT)) blockSelection = BLOCK_PLANK;

        if (!paused) {
            // --- Update camera and direction ---

            UpdateFreeCamera(&camera, 10.0f, &cameraYaw, &cameraPitch); // Move camera with user input


            // --- Raycasting from screen center ---
            Vector2 screenCenter = { screenWidth / 2.0f, screenHeight / 2.0f };
            // This is where we grab the ray...
            // Ray ray = GetMouseRay(screenCenter, camera);
            Vector3 camDir = {
                cosf(cameraPitch) * sinf(cameraYaw),
                sinf(cameraPitch),
                cosf(cameraPitch) * cosf(cameraYaw)
            };

            Ray ray = {
                .position = camera.position,
                .direction = Vector3Normalize(camDir)
            };
            hit = RaycastChunk(&chunk, ray.position, ray.direction, 10.0f);

            // --- Begin 3D rendering ---
            BeginMode3D(camera);

            DrawMesh(chunkMesh, mat, MatrixIdentity());

            if (hit.hit) {
                // Draw a wireframe cube where the ray hit
                DrawCubeWires(Vector3Add(hit.position, (Vector3){0.5f, 0.5f, 0.5f}), 1.02f, 1.02f, 1.02f, BLACK);
                //DrawFaceHighlight(hit.position, hit.normal);  // Highlight the specific face hit
            }

            // Draw a lil debug cube where the player is looking.
            //Vector3 hitPoint = Vector3Add(ray.position, Vector3Scale(ray.direction, hit.t));
            //DrawCubeWires(hitPoint, 0.05f, 0.05f, 0.05f, RED);

            EndMode3D();

            // --- Draw crosshair in screen center ---
            DrawLine(screenWidth/2 - 5, screenHeight/2, screenWidth/2 + 5, screenHeight/2, DARKGRAY);
            DrawLine(screenWidth/2, screenHeight/2 - 5, screenWidth/2, screenHeight/2 + 5, DARKGRAY);

            // -- Draw debug info ---
            DrawText(TextFormat("Facing: %s", GetCompassDirection(cameraYaw)), 10, 10, 20, DARKGRAY);
            DrawText(TextFormat("Yaw: %.1f°  Pitch: %.1f°", cameraYaw * RAD2DEG, cameraPitch * RAD2DEG), 10, 30, 20, GRAY);
        }

        // --- Draw pause menu if paused ---
        if (paused) {
            DrawRectangle(0, 0, screenWidth, screenHeight, Fade(DARKGRAY, 0.5f));
            DrawText("Paused", screenWidth / 2 - MeasureText("Paused", 40) / 2, screenHeight / 2 - 20, 40, RAYWHITE);
            DrawText("Press ESC to resume", screenWidth / 2 - MeasureText("Press ESC to resume", 20) / 2, screenHeight / 2 + 30, 20, LIGHTGRAY);
        }

        EndDrawing();

        // TODO: Shoudn't all this block handling be handled in playerController.c?

        // --- Handle block removal (left click) ---
        if (hit.hit && IsMouseButtonPressed(MOUSE_LEFT_BUTTON)) {
            chunk.blocks[(int)hit.position.x][(int)hit.position.y][(int)hit.position.z].type = BLOCK_AIR;
            chunkMesh = GenerateChunkMesh(&chunk);  // Rebuild mesh after change
        }

        // --- Handle block placement (right click) ---
        if (hit.hit && IsMouseButtonPressed(MOUSE_RIGHT_BUTTON)) {
            int px = (int)(hit.position.x + hit.normal.x);
            int py = (int)(hit.position.y + hit.normal.y);
            int pz = (int)(hit.position.z + hit.normal.z);

            // Bounds check
            if (px >= 0 && px < CHUNK_SIZE_X &&
                py >= 0 && py < CHUNK_SIZE_Y &&
                pz >= 0 && pz < CHUNK_SIZE_Z) {

                chunk.blocks[px][py][pz].type = blockSelection;
            chunkMesh = GenerateChunkMesh(&chunk);

            printf("Hit at (%f %f %f), normal (%f %f %f), placing at (%d %d %d)\n",
                   hit.position.x, hit.position.y, hit.position.z,
                   hit.normal.x, hit.normal.y, hit.normal.z,
                   px, py, pz);
                }
        }
    }

    // --- Cleanup ---
    UnloadTexture(atlas);
    UnloadMesh(chunkMesh);
    UnloadMaterial(mat);
    CloseWindow();
    return 0;
}