/**
 * Copyright (c) 2024 Dominic Masters
 * 
 * This software is released under the MIT License.
 * https://opensource.org/licenses/MIT
 */

#include "drawmap.h"
#include "assert/assert.h"
#include "display/symbol.h"

void drawMap(
  const map_t *map,
  const uint16_t cameraX,
  const uint16_t cameraY,
  const uint16_t drawX,
  const uint16_t drawY,
  const uint16_t drawWidth,
  const uint16_t drawHeight
) {
  assertNotNull(map, "Map cannot be NULL.");
  assertTrue(drawX < FRAME_WIDTH, "Map is too far right.");
  assertTrue(drawY < FRAME_HEIGHT, "Map is too far down.");
  assertTrue(drawWidth > 0, "Map is too narrow.");
  assertTrue(drawHeight > 0, "Map is too short.");
  assertTrue(drawX + drawWidth <= FRAME_WIDTH, "Map is too wide.");
  assertTrue(drawY + drawHeight <= FRAME_HEIGHT, "Map is too tall.");

  entity_t *ent;
  tile_t tile;
  uint32_t i;
  char_t *bufferDest;
  uint8_t *colorDest;

  // If the size of the map's smaller than the frame, center it, otherwise use
  // the cameraPosition as the center point.
  int16_t offsetX = 0, offsetY = 0;
  if(map->width < drawWidth) {
    offsetX = (drawWidth - map->width) / 2;
  } else {
    // Clamp to map bounds
    if(cameraX < drawWidth / 2) {
      offsetX = 0;
    } else if(cameraX >= map->width - (drawWidth / 2)) {
      offsetX = -(map->width - drawWidth);
    } else {
      offsetX = -(cameraX - (drawWidth / 2));
    }
  }

  if(map->height < drawHeight) {
    offsetY = (drawHeight - map->height) / 2;
  } else {
    // Clamp to map bounds
    if(cameraY < drawHeight / 2) {
      offsetY = 0;
    } else if(cameraY >= map->height - (drawHeight / 2)) {
      offsetY = -(map->height - drawHeight);
    } else {
      offsetY = -(cameraY - (drawHeight / 2));
    }
  }

  // Draw the map
  i = 0;
  for(uint16_t y = 0; y < drawHeight; y++) {
    bufferDest = &FRAME_BUFFER[(drawY + y) * FRAME_WIDTH + drawX];
    colorDest = &FRAME_COLOR[(drawY + y) * FRAME_WIDTH + drawX];

    for(uint16_t x = 0; x < drawWidth; x++) {
      if(x < offsetX || y < offsetY || x >= map->width + offsetX || y >= map->height + offsetY) {
        colorDest[x] = COLOR_BLACK;
        bufferDest[x] = ' ';
        continue;
      }

      // Entity?
      ent = mapEntityGetByPosition(map, x - offsetX, y - offsetY);
      if(ent != NULL) {
        colorDest[x] = symbolGetColorByEntity(ent);
        bufferDest[x] = symbolGetCharByEntity(ent);
        continue;
      }

      // Tile?
      tile = mapTileGetByPosition(map, x - offsetX, y - offsetY, 0);
      colorDest[x] = symbolGetColorByTile(tile);
      bufferDest[x] = symbolGetCharByTile(tile);
    }
  }
}