#include "map.h"
#include "rng/rng.h"
#include "settings.h"
#include "utils.h"
#include <math.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

void map_init(Map *map) {
  for (int y = 0; y < MAP_HEIGHT; y++) {
    for (int x = 0; x < MAP_WIDTH; x++) {
      map->tiles[y][x] = TILE_WALL;
    }
  }
  memset(map->light_map, 0, sizeof(map->light_map));
  memset(map->remembered, 0, sizeof(map->remembered));
  memset(map->door_open_from, 255, sizeof(map->door_open_from));
  memset(map->door_anim_timer, 0, sizeof(map->door_anim_timer));
  memset(map->door_anim_target, 0, sizeof(map->door_anim_target));
  map->room_count = 0;
}

int is_floor(const Map *map, int x, int y) {
  if (!in_bounds(x, y, MAP_WIDTH, MAP_HEIGHT))
    return 0;
  return map->tiles[y][x] == TILE_FLOOR || map->tiles[y][x] == TILE_STAIRS || map->tiles[y][x] == TILE_DOOR_OPEN ||
         map->tiles[y][x] == TILE_DOOR_RUINED || map->tiles[y][x] == TILE_DOOR_CLOSED ||
         map->tiles[y][x] == TILE_RUBBLE || map->tiles[y][x] == TILE_SHALLOW_WATER;
}

void get_room_center(Room *room, int *cx, int *cy) {
  *cx = room->x + room->w / 2;
  *cy = room->y + room->h / 2;
}

// Carve a room into the map
static void carve_room(Map *map, Room *room) {
  for (int y = room->y; y < room->y + room->h; y++) {
    for (int x = room->x; x < room->x + room->w; x++) {
      if (!in_bounds(x, y, MAP_WIDTH, MAP_HEIGHT))
        continue;

      int local_x = x - room->x;
      int local_y = y - room->y;
      int carved = 1;

      if ((room->type == ROOM_SHRINE || room->type == ROOM_VAULT) &&
          ((local_x == 0 && local_y == 0) || (local_x == room->w - 1 && local_y == 0) ||
           (local_x == 0 && local_y == room->h - 1) || (local_x == room->w - 1 && local_y == room->h - 1))) {
        carved = 0;
      }

      if (room->type == ROOM_CRYPT &&
          ((local_x == 0 || local_x == room->w - 1) && (local_y == 0 || local_y == room->h - 1)))
        carved = 0;

      if (carved)
        map->tiles[y][x] = TILE_FLOOR;
    }
  }
}

// Carve a horizontal corridor
static void carve_h_corridor(Map *map, int x1, int x2, int y) {
  int start = (x1 < x2) ? x1 : x2;
  int end = (x1 < x2) ? x2 : x1;
  for (int x = start; x <= end; x++) {
    if (in_bounds(x, y, MAP_WIDTH, MAP_HEIGHT)) {
      map->tiles[y][x] = TILE_FLOOR;
    }
  }
}

// Carve a vertical corridor
static void carve_v_corridor(Map *map, int x, int y1, int y2) {
  int start = (y1 < y2) ? y1 : y2;
  int end = (y1 < y2) ? y2 : y1;
  for (int y = start; y <= end; y++) {
    if (in_bounds(x, y, MAP_WIDTH, MAP_HEIGHT)) {
      map->tiles[y][x] = TILE_FLOOR;
    }
  }
}

// Check if a room overlaps with existing rooms
static int room_overlaps(Room *rooms, int count, Room *new_room) {
  // Add padding to prevent rooms from touching
  for (int i = 0; i < count; i++) {
    Room *r = &rooms[i];
    if (!(new_room->x > r->x + r->w + 2 || new_room->x + new_room->w + 2 < r->x || new_room->y > r->y + r->h + 2 ||
          new_room->y + new_room->h + 2 < r->y)) {
      return 1;
    }
  }
  return 0;
}

static RoomType pick_room_type(int floor, int room_index) {
  if (room_index == 0)
    return ROOM_START;

  int roll = rng_int(0, 99);
  if (floor <= 1) {
    if (roll < 35)
      return ROOM_GUARD;
    if (roll < 55)
      return ROOM_ARMORY;
    if (roll < 75)
      return ROOM_SHRINE;
    return ROOM_CRYPT;
  }
  if (floor == 2) {
    if (roll < 40)
      return ROOM_CISTERN;
    if (roll < 60)
      return ROOM_GUARD;
    if (roll < 80)
      return ROOM_SHRINE;
    return ROOM_CRYPT;
  }
  if (floor == 3) {
    if (roll < 35)
      return ROOM_CRYPT;
    if (roll < 60)
      return ROOM_LIBRARY;
    if (roll < 80)
      return ROOM_CISTERN;
    return ROOM_VAULT;
  }
  if (floor == 4) {
    if (roll < 35)
      return ROOM_FORGE;
    if (roll < 55)
      return ROOM_ARMORY;
    if (roll < 75)
      return ROOM_CRYPT;
    return ROOM_VAULT;
  }
  if (roll < 30)
    return ROOM_VAULT;
  if (roll < 55)
    return ROOM_CRYPT;
  if (roll < 75)
    return ROOM_FORGE;
  return ROOM_SHRINE;
}

static void room_size_for_type(RoomType type, int *w, int *h) {
  switch (type) {
  case ROOM_START:
    *w = rng_int(7, 10);
    *h = rng_int(6, 8);
    break;
  case ROOM_GUARD:
  case ROOM_ARMORY:
    *w = rng_int(6, 11);
    *h = rng_int(5, 8);
    break;
  case ROOM_SHRINE:
  case ROOM_VAULT:
    *w = rng_int(7, 11);
    *h = rng_int(7, 11);
    break;
  case ROOM_CISTERN:
    *w = rng_int(8, 14);
    *h = rng_int(6, 10);
    break;
  case ROOM_CRYPT:
  case ROOM_LIBRARY:
    *w = rng_int(8, 13);
    *h = rng_int(5, 9);
    break;
  case ROOM_FORGE:
    *w = rng_int(7, 12);
    *h = rng_int(6, 9);
    break;
  }
}

// Generate rooms for this floor
static int generate_rooms(Map *map, Room *rooms, int floor) {
  int room_count = 0;
  int attempts = 0;
  int max_attempts = 250;

  // Room count varies by floor, but capped at max_rooms
  int target_rooms = 8 + (floor % 3) + rng_int(0, 3);
  if (target_rooms > MAX_ROOMS)
    target_rooms = MAX_ROOMS;

  while (room_count < target_rooms && attempts < max_attempts) {
    attempts++;

    RoomType type = pick_room_type(floor, room_count);
    int w, h;
    room_size_for_type(type, &w, &h);

    int x, y;
    if (room_count == 0) {
      x = rng_int(3, 8);
      y = rng_int(3, MAP_HEIGHT - h - 4);
    } else {
      x = rng_int(2, MAP_WIDTH - w - 3);
      y = rng_int(2, MAP_HEIGHT - h - 3);
    }

    Room new_room = {x, y, w, h, type};

    if (!room_overlaps(rooms, room_count, &new_room)) {
      rooms[room_count] = new_room;
      carve_room(map, &new_room);
      room_count++;
    }
  }

  return room_count;
}

// Check if a tile is at a room boundary (adjacent to wall but inside room)
static int is_room_boundary(Map *map, int x, int y) {
  // Must be floor
  if (map->tiles[y][x] != TILE_FLOOR)
    return 0;
  // Must have at least one adjacent wall
  if (in_bounds(x - 1, y, MAP_WIDTH, MAP_HEIGHT) && map->tiles[y][x - 1] == TILE_WALL)
    return 1;
  if (in_bounds(x + 1, y, MAP_WIDTH, MAP_HEIGHT) && map->tiles[y][x + 1] == TILE_WALL)
    return 1;
  if (in_bounds(x, y - 1, MAP_WIDTH, MAP_HEIGHT) && map->tiles[y - 1][x] == TILE_WALL)
    return 1;
  if (in_bounds(x, y + 1, MAP_WIDTH, MAP_HEIGHT) && map->tiles[y + 1][x] == TILE_WALL)
    return 1;
  return 0;
}

// A corridor tile is a narrow floor passage with walls on at least 2 sides.
static int is_corridor_tile(const Map *map, int x, int y) {
  if (map->tiles[y][x] != TILE_FLOOR)
    return 0;
  int walls = 0;
  if (y > 0 && map->tiles[y - 1][x] == TILE_WALL)
    walls++;
  if (y < MAP_HEIGHT - 1 && map->tiles[y + 1][x] == TILE_WALL)
    walls++;
  if (x > 0 && map->tiles[y][x - 1] == TILE_WALL)
    walls++;
  if (x < MAP_WIDTH - 1 && map->tiles[y][x + 1] == TILE_WALL)
    walls++;
  return walls >= 2;
}

static int tile_in_any_room(int x, int y, Room *rooms, int room_count) {
  for (int i = 0; i < room_count; i++) {
    if (x >= rooms[i].x && x < rooms[i].x + rooms[i].w && y >= rooms[i].y && y < rooms[i].y + rooms[i].h)
      return 1;
  }
  return 0;
}

static int tile_in_room(const Room *room, int x, int y) {
  return x >= room->x && x < room->x + room->w && y >= room->y && y < room->y + room->h;
}

Room *map_room_at(Map *map, int x, int y) {
  for (int i = 0; i < map->room_count; i++) {
    if (tile_in_room(&map->rooms[i], x, y))
      return &map->rooms[i];
  }
  return NULL;
}

static int protected_room_tile(const Room *room, int x, int y) {
  int cx, cy;
  get_room_center((Room *)room, &cx, &cy);
  return (abs(x - cx) <= 1 && abs(y - cy) <= 1) || x == room->x || y == room->y || x == room->x + room->w - 1 ||
         y == room->y + room->h - 1;
}

static void set_room_tile(Map *map, const Room *room, int x, int y, TileType tile) {
  if (!in_bounds(x, y, MAP_WIDTH, MAP_HEIGHT) || !tile_in_room(room, x, y) || protected_room_tile(room, x, y))
    return;
  if (map->tiles[y][x] == TILE_FLOOR)
    map->tiles[y][x] = tile;
}

static void decorate_room(Map *map, const Room *room, int floor) {
  int cx, cy;
  get_room_center((Room *)room, &cx, &cy);

  switch (room->type) {
  case ROOM_START:
    if (room->w >= 8 && room->h >= 6) {
      set_room_tile(map, room, room->x + 2, room->y + 2, TILE_RUBBLE);
      set_room_tile(map, room, room->x + room->w - 3, room->y + room->h - 3, TILE_RUBBLE);
    }
    break;
  case ROOM_GUARD:
    for (int y = room->y + 2; y < room->y + room->h - 2; y += 3) {
      set_room_tile(map, room, room->x + 2, y, TILE_STATUE);
      set_room_tile(map, room, room->x + room->w - 3, y, TILE_STATUE);
    }
    break;
  case ROOM_SHRINE:
    set_room_tile(map, room, cx - 2, cy, TILE_STATUE);
    set_room_tile(map, room, cx + 2, cy, TILE_STATUE);
    set_room_tile(map, room, cx, cy - 2, TILE_RUBBLE);
    set_room_tile(map, room, cx, cy + 2, TILE_RUBBLE);
    break;
  case ROOM_CISTERN:
    for (int y = cy - 1; y <= cy + 1; y++) {
      for (int x = cx - 2; x <= cx + 2; x++) {
        if ((x + y + floor) % 5 != 0)
          set_room_tile(map, room, x, y, TILE_SHALLOW_WATER);
      }
    }
    break;
  case ROOM_ARMORY:
    for (int x = room->x + 2; x < room->x + room->w - 2; x += 3) {
      set_room_tile(map, room, x, room->y + 2, TILE_RUBBLE);
      set_room_tile(map, room, x, room->y + room->h - 3, TILE_RUBBLE);
    }
    break;
  case ROOM_CRYPT:
    for (int x = room->x + 2; x < room->x + room->w - 2; x += 3) {
      set_room_tile(map, room, x, cy - 1, TILE_STATUE);
      set_room_tile(map, room, x, cy + 1, TILE_RUBBLE);
    }
    break;
  case ROOM_LIBRARY:
    for (int y = room->y + 2; y < room->y + room->h - 2; y += 2) {
      set_room_tile(map, room, room->x + 2, y, TILE_STATUE);
      set_room_tile(map, room, room->x + room->w - 3, y, TILE_RUBBLE);
    }
    break;
  case ROOM_FORGE:
    for (int y = cy - 1; y <= cy + 1; y++) {
      set_room_tile(map, room, cx - 2, y, TILE_RUBBLE);
      set_room_tile(map, room, cx + 2, y, TILE_RUBBLE);
    }
    set_room_tile(map, room, cx, cy - 2, TILE_STATUE);
    break;
  case ROOM_VAULT:
    set_room_tile(map, room, cx - 2, cy - 2, TILE_STATUE);
    set_room_tile(map, room, cx + 2, cy - 2, TILE_STATUE);
    set_room_tile(map, room, cx - 2, cy + 2, TILE_STATUE);
    set_room_tile(map, room, cx + 2, cy + 2, TILE_STATUE);
    break;
  }
}

static void decorate_rooms(Map *map, Room *rooms, int room_count, int floor) {
  for (int i = 0; i < room_count; i++) {
    decorate_room(map, &rooms[i], floor);
  }
}

// Place doors at corridor-room junctions.
// Doors sit on corridor tiles, not room tiles, so they occupy the actual doorway.
static void place_doors(Map *map, Room *rooms, int room_count) {
  for (int y = 0; y < MAP_HEIGHT; y++) {
    for (int x = 0; x < MAP_WIDTH; x++) {
      if (map->tiles[y][x] != TILE_FLOOR)
        continue;
      if (!is_corridor_tile(map, x, y))
        continue;
      // Don't place doors inside rooms — corridors are between rooms
      if (tile_in_any_room(x, y, rooms, room_count))
        continue;
      // Corridor must be adjacent to a room floor tile
      const int dx[4] = {0, 0, 1, -1};
      const int dy[4] = {1, -1, 0, 0};
      for (int i = 0; i < 4; i++) {
        int nx = x + dx[i];
        int ny = y + dy[i];
        if (!in_bounds(nx, ny, MAP_WIDTH, MAP_HEIGHT))
          continue;
        if (map->tiles[ny][nx] != TILE_FLOOR)
          continue;
        if (tile_in_any_room(nx, ny, rooms, room_count)) {
          map->tiles[y][x] = TILE_DOOR_CLOSED;
          break;
        }
      }
    }
  }
}

// Connect all rooms with corridors
static int room_distance2(Room *a, Room *b) {
  int ax, ay, bx, by;
  get_room_center(a, &ax, &ay);
  get_room_center(b, &bx, &by);
  int dx = ax - bx;
  int dy = ay - by;
  return dx * dx + dy * dy;
}

static void carve_connection(Map *map, Room *a, Room *b) {
  int cx1, cy1, cx2, cy2;
  get_room_center(a, &cx1, &cy1);
  get_room_center(b, &cx2, &cy2);

  if (rng_int(0, 2) == 0) {
    int mid_x = (cx1 + cx2) / 2 + rng_int(-3, 3);
    carve_h_corridor(map, cx1, mid_x, cy1);
    carve_v_corridor(map, mid_x, cy1, cy2);
    carve_h_corridor(map, mid_x, cx2, cy2);
  } else if (rng_int(0, 1) == 0) {
    carve_h_corridor(map, cx1, cx2, cy1);
    carve_v_corridor(map, cx2, cy1, cy2);
  } else {
    carve_v_corridor(map, cx1, cy1, cy2);
    carve_h_corridor(map, cx1, cx2, cy2);
  }
}

static void connect_rooms(Map *map, Room *rooms, int room_count) {
  for (int i = 1; i < room_count; i++) {
    int nearest = 0;
    int best = room_distance2(&rooms[i], &rooms[0]);
    for (int j = 1; j < i; j++) {
      int dist = room_distance2(&rooms[i], &rooms[j]);
      if (dist < best) {
        best = dist;
        nearest = j;
      }
    }
    carve_connection(map, &rooms[i], &rooms[nearest]);
  }

  for (int i = 0; i < room_count; i++) {
    if (rng_int(0, 99) >= 28)
      continue;
    int j = rng_int(0, room_count - 1);
    if (i != j)
      carve_connection(map, &rooms[i], &rooms[j]);
  }

  place_doors(map, rooms, room_count);
}

// Place stairs in the last room (furthest from start)
static void place_stairs(Map *map, Room *rooms, int room_count) {
  if (room_count > 0) {
    Room *last_room = &rooms[room_count - 1];
    int cx, cy;
    get_room_center(last_room, &cx, &cy);

    // Ensure stairs are placed on a floor tile, not a wall
    if (in_bounds(cx, cy, MAP_WIDTH, MAP_HEIGHT) && map->tiles[cy][cx] == TILE_FLOOR) {
      map->tiles[cy][cx] = TILE_STAIRS;
      return;
    }

    // 3x3 fallback
    for (int dy = -1; dy <= 1; dy++) {
      for (int dx = -1; dx <= 1; dx++) {
        int nx = cx + dx;
        int ny = cy + dy;
        if (in_bounds(nx, ny, MAP_WIDTH, MAP_HEIGHT) && map->tiles[ny][nx] == TILE_FLOOR) {
          map->tiles[ny][nx] = TILE_STAIRS;
          return;
        }
      }
    }

    // Expanded fallback: scan the room for any floor tile
    for (int dy = 0; dy < last_room->h; dy++) {
      for (int dx = 0; dx < last_room->w; dx++) {
        int nx = last_room->x + dx;
        int ny = last_room->y + dy;
        if (in_bounds(nx, ny, MAP_WIDTH, MAP_HEIGHT) && map->tiles[ny][nx] == TILE_FLOOR) {
          map->tiles[ny][nx] = TILE_STAIRS;
          return;
        }
      }
    }

    // Final fallback: force the center tile to stairs regardless of type
    fprintf(stderr, "Warning: No floor tile found for stairs at room center (%d, %d). Forcing stairs placement.\n", cx,
            cy);
    if (in_bounds(cx, cy, MAP_WIDTH, MAP_HEIGHT)) {
      if (map->tiles[cy][cx] == TILE_WALL) {
        map->tiles[cy][cx] = TILE_FLOOR;
      }
      map->tiles[cy][cx] = TILE_STAIRS;
    }
  }
}

// Get a random floor tile (for player/enemy spawn)
void get_random_floor_tile(Map *map, int *x, int *y, int attempts) {
  *x = -1;
  *y = -1;

  for (int i = 0; i < attempts; i++) {
    int tx = rng_int(1, MAP_WIDTH - 2);
    int ty = rng_int(1, MAP_HEIGHT - 2);

    if (map->tiles[ty][tx] == TILE_FLOOR) {
      *x = tx;
      *y = ty;
      return;
    }
  }

  // Fallback: search from top-left
  for (int ty = 1; ty < MAP_HEIGHT - 1; ty++) {
    for (int tx = 1; tx < MAP_WIDTH - 1; tx++) {
      if (map->tiles[ty][tx] == TILE_FLOOR) {
        *x = tx;
        *y = ty;
        return;
      }
    }
  }
}

int get_room_floor_tile(const Map *map, const Room *room, int *x, int *y) {
  *x = -1;
  *y = -1;

  int cx = room->x + room->w / 2;
  int cy = room->y + room->h / 2;
  if (in_bounds(cx, cy, MAP_WIDTH, MAP_HEIGHT) && map->tiles[cy][cx] == TILE_FLOOR) {
    *x = cx;
    *y = cy;
    return 1;
  }

  for (int radius = 1; radius < room->w + room->h; radius++) {
    for (int yy = cy - radius; yy <= cy + radius; yy++) {
      for (int xx = cx - radius; xx <= cx + radius; xx++) {
        if (!tile_in_room(room, xx, yy) || !in_bounds(xx, yy, MAP_WIDTH, MAP_HEIGHT))
          continue;
        if (map->tiles[yy][xx] == TILE_FLOOR) {
          *x = xx;
          *y = yy;
          return 1;
        }
      }
    }
  }

  return 0;
}

int get_random_floor_tile_excluding_room(Map *map, const Room *excluded, int *x, int *y, int attempts) {
  *x = -1;
  *y = -1;

  for (int i = 0; i < attempts; i++) {
    int tx = rng_int(1, MAP_WIDTH - 2);
    int ty = rng_int(1, MAP_HEIGHT - 2);

    if (map->tiles[ty][tx] == TILE_FLOOR && (excluded == NULL || !tile_in_room(excluded, tx, ty))) {
      *x = tx;
      *y = ty;
      return 1;
    }
  }

  for (int ty = 1; ty < MAP_HEIGHT - 1; ty++) {
    for (int tx = 1; tx < MAP_WIDTH - 1; tx++) {
      if (map->tiles[ty][tx] == TILE_FLOOR && (excluded == NULL || !tile_in_room(excluded, tx, ty))) {
        *x = tx;
        *y = ty;
        return 1;
      }
    }
  }

  return 0;
}

int map_validate_layout(const Map *map) {
  if (map->room_count <= 0)
    return 0;

  int sx, sy;
  if (!get_room_floor_tile(map, &map->rooms[0], &sx, &sy))
    return 0;

  unsigned char visited[MAP_HEIGHT][MAP_WIDTH];
  Vec2 queue[MAP_HEIGHT * MAP_WIDTH];
  memset(visited, 0, sizeof(visited));

  int head = 0;
  int tail = 0;
  queue[tail++] = (Vec2){sx, sy};
  visited[sy][sx] = 1;

  while (head < tail) {
    Vec2 p = queue[head++];
    const int dx[4] = {0, 0, 1, -1};
    const int dy[4] = {1, -1, 0, 0};
    for (int i = 0; i < 4; i++) {
      int nx = p.x + dx[i];
      int ny = p.y + dy[i];
      if (!in_bounds(nx, ny, MAP_WIDTH, MAP_HEIGHT) || visited[ny][nx] || !is_floor(map, nx, ny))
        continue;
      visited[ny][nx] = 1;
      queue[tail++] = (Vec2){nx, ny};
    }
  }

  int stairs = 0;
  for (int y = 0; y < MAP_HEIGHT; y++) {
    for (int x = 0; x < MAP_WIDTH; x++) {
      if (is_floor(map, x, y) && !visited[y][x])
        return 0;
      if (map->tiles[y][x] == TILE_STAIRS) {
        if (!visited[y][x])
          return 0;
        stairs++;
      }
    }
  }

  return stairs == 1;
}

void dungeon_generate(Dungeon *d, Map *map, int floor_num) {
  for (int attempt = 0; attempt < 4; attempt++) {
    map_init(map);
    map->room_count = generate_rooms(map, map->rooms, floor_num);
    connect_rooms(map, map->rooms, map->room_count);
    decorate_rooms(map, map->rooms, map->room_count, floor_num);
    place_stairs(map, map->rooms, map->room_count);

    if (map_validate_layout(map))
      break;
  }

  // Store dungeon state
  d->current_floor = floor_num;
  d->room_count = map->room_count;
  memcpy(d->rooms, map->rooms, sizeof(Room) * map->room_count);
}

int is_in_view_range(int x, int y, int view_x, int view_y, int range) {
  int dx = x - view_x;
  int dy = y - view_y;
  return (dx * dx + dy * dy) <= (range * range);
}

static int trace_line_of_sight(const Map *map, int x1, int y1, int x2, int y2) {
  int dx = abs(x2 - x1);
  int dy = abs(y2 - y1);
  int sx = (x1 < x2) ? 1 : -1;
  int sy = (y1 < y2) ? 1 : -1;
  int err = dx - dy;
  int x = x1;
  int y = y1;

  while (1) {
    if (!in_bounds(x, y, MAP_WIDTH, MAP_HEIGHT))
      return 0;

    if (x == x2 && y == y2)
      return 1;

    TileType t = map->tiles[y][x];
    if ((t == TILE_WALL || t == TILE_DOOR_CLOSED || t == TILE_STATUE) && !(x == x1 && y == y1))
      return 0;

    int e2 = 2 * err;
    if (e2 > -dy) {
      err -= dy;
      x += sx;
    }
    if (e2 < dx) {
      err += dx;
      y += sy;
    }
  }
}

int has_line_of_sight(const Map *map, int x1, int y1, int x2, int y2) {
  if (!in_bounds(x1, y1, MAP_WIDTH, MAP_HEIGHT) || !in_bounds(x2, y2, MAP_WIDTH, MAP_HEIGHT))
    return 0;
  return trace_line_of_sight(map, x1, y1, x2, y2);
}

int can_see_entity(const Map *map, int from_x, int from_y, int to_x, int to_y, int range) {
  if (!is_in_view_range(to_x, to_y, from_x, from_y, range))
    return 0;
  if (!has_line_of_sight(map, from_x, from_y, to_x, to_y))
    return 0;
  return tile_brightness(map, to_x, to_y) > LIGHT_SIGHT_THRESHOLD;
}

static int is_solid(const Map *map, int sub_x, int sub_y) {
  int map_w = MAP_WIDTH;
  int map_h = MAP_HEIGHT;
  int tx = sub_x / SUB_TILE_RES;
  int ty = sub_y / SUB_TILE_RES;
  if (tx < 0 || tx >= map_w || ty < 0 || ty >= map_h)
    return 1;
  TileType t = map->tiles[ty][tx];
  return t == TILE_WALL || t == TILE_DOOR_CLOSED || t == TILE_STATUE;
}

static float smoothstep_light(float edge0, float edge1, float x) {
  float t = (x - edge0) / (edge1 - edge0);
  if (t < 0.0f)
    return 0.0f;
  if (t > 1.0f)
    return 1.0f;
  return t * t * (3.0f - 2.0f * t);
}

static int trace_sub_los(const Map *map, int sx, int sy, int tx, int ty) {
  int dx = abs(tx - sx);
  int dy = abs(ty - sy);
  int step_x = (sx < tx) ? 1 : -1;
  int step_y = (sy < ty) ? 1 : -1;
  int err = dx - dy;
  int x = sx, y = sy;

  while (1) {
    if (x == tx && y == ty)
      return 1;
    if (is_solid(map, x, y) && !(x == sx && y == sy))
      return 0;
    int e2 = 2 * err;
    if (e2 > -dy) {
      err -= dy;
      x += step_x;
    }
    if (e2 < dx) {
      err += dx;
      y += step_y;
    }
  }
}

void compute_lighting(Map *map, const LightSource *sources, int num_sources) {
  memset(map->light_map, 0, sizeof(map->light_map));

  int map_sub_w = MAP_WIDTH * SUB_TILE_RES;
  int map_sub_h = MAP_HEIGHT * SUB_TILE_RES;

  for (int si = 0; si < num_sources; si++) {
    int cx = sources[si].x * SUB_TILE_RES + SUB_TILE_RES / 2;
    int cy = sources[si].y * SUB_TILE_RES + SUB_TILE_RES / 2;
    int range_sub = sources[si].range * SUB_TILE_RES;
    int intensity = sources[si].intensity;

    for (int dy = -range_sub; dy <= range_sub; dy++) {
      for (int dx = -range_sub; dx <= range_sub; dx++) {
        int sub_x = cx + dx;
        int sub_y = cy + dy;

        if (sub_x < 0 || sub_x >= map_sub_w || sub_y < 0 || sub_y >= map_sub_h)
          continue;

        int dist_sq = dx * dx + dy * dy;
        if (dist_sq > range_sub * range_sub)
          continue;

        if (!trace_sub_los(map, cx, cy, sub_x, sub_y))
          continue;

        float dist = sqrtf((float)dist_sq);
        float t = dist / (float)range_sub;
        float brightness = 1.0f - smoothstep_light(0.35f, 1.0f, t);
        int val = (int)(brightness * (float)intensity);

        if (val > map->light_map[sub_y][sub_x])
          map->light_map[sub_y][sub_x] = (unsigned char)val;
      }
    }

    int src_x = sources[si].x;
    int src_y = sources[si].y;
    int src_range = sources[si].range;
    int src_intensity = sources[si].intensity;

    for (int ty = 0; ty < MAP_HEIGHT; ty++) {
      for (int tx = 0; tx < MAP_WIDTH; tx++) {
        if (map->tiles[ty][tx] != TILE_WALL && map->tiles[ty][tx] != TILE_DOOR_CLOSED)
          continue;
        if (!is_in_view_range(tx, ty, src_x, src_y, src_range))
          continue;
        if (!has_line_of_sight(map, src_x, src_y, tx, ty))
          continue;

        int dx = tx - src_x;
        int dy = ty - src_y;
        float t = sqrtf((float)(dx * dx + dy * dy)) / (float)src_range;
        float fb = 1.0f - smoothstep_light(0.35f, 1.0f, t);
        int val = (int)(fb * (float)src_intensity);

        int base_x = tx * SUB_TILE_RES;
        int base_y = ty * SUB_TILE_RES;
        for (int cy2 = 0; cy2 < SUB_TILE_RES; cy2++) {
          for (int cx2 = 0; cx2 < SUB_TILE_RES; cx2++) {
            if (val > map->light_map[base_y + cy2][base_x + cx2])
              map->light_map[base_y + cy2][base_x + cx2] = (unsigned char)val;
          }
        }
      }
    }
  }

  for (int ty = 0; ty < MAP_HEIGHT; ty++) {
    for (int tx = 0; tx < MAP_WIDTH; tx++) {
      int max_bright = 0;
      int bx = tx * SUB_TILE_RES;
      int by = ty * SUB_TILE_RES;
      for (int dy = 0; dy < SUB_TILE_RES; dy++) {
        for (int dx = 0; dx < SUB_TILE_RES; dx++) {
          int v = map->light_map[by + dy][bx + dx];
          if (v > max_bright)
            max_bright = v;
        }
      }
      if (max_bright > LIGHT_SIGHT_THRESHOLD)
        map->remembered[ty][tx] = 1;
    }
  }
}

int tile_brightness(const Map *map, int tx, int ty) {
  int sum = 0;
  int base_x = tx * SUB_TILE_RES;
  int base_y = ty * SUB_TILE_RES;
  for (int dy = 0; dy < SUB_TILE_RES; dy++) {
    for (int dx = 0; dx < SUB_TILE_RES; dx++) {
      sum += map->light_map[base_y + dy][base_x + dx];
    }
  }
  return sum / (SUB_TILE_RES * SUB_TILE_RES);
}

int is_tile_revealed(const Map *map, int tx, int ty) {
  return tile_brightness(map, tx, ty) > LIGHT_SIGHT_THRESHOLD;
}