import sys, os
import argparse
from datetime import datetime
import json
import math

# Values defined within C
CHUNK_WIDTH = 8
CHUNK_HEIGHT = 8
CHUNK_TILE_COUNT = CHUNK_WIDTH * CHUNK_HEIGHT
CHUNK_ENTITY_COUNT_MAX = 8

ENTITY_TYPE_MAP = {
  "npc": "ENTITY_TYPE_NPC",
}

# Check if the script is run with the correct arguments
parser = argparse.ArgumentParser(description="Generate chunk header files")
parser.add_argument('--output', required=True, help='Dir to output headers')
parser.add_argument('--input', required=True, help='Input JSON file from tiled')
args = parser.parse_args()

# Ensure outdir exists
outputDir = args.output
os.makedirs(outputDir, exist_ok=True)

# Create world directory if it does not exist
worldDir = os.path.join(outputDir, "world")
os.makedirs(worldDir, exist_ok=True)

# Create chunks directory if it does not exist
chunksDir = os.path.join(worldDir, "chunk")
os.makedirs(chunksDir, exist_ok=True)

# Some vars used during printing
now = datetime.now().strftime("%Y-%m-%d %H:%M:%S")

# Read the input JSON file
inputFile = args.input
if not os.path.isfile(inputFile):
  print(f"Error: Input file '{inputFile}' does not exist.")
  sys.exit(1)

with open(inputFile, 'r') as f:
  data = json.load(f)
  
# Data should have height key
if 'height' not in data or 'width' not in data:
  print(f"Error: Input file '{inputFile}' does not contain 'height' or 'width' key.")
  sys.exit(1)

if 'tilewidth' not in data or 'tileheight' not in data:
  print(f"Error: Input file '{inputFile}' does not contain 'tilewidth' or 'tileheight' key.")
  sys.exit(1)

if 'infinite' not in data or not isinstance(data['infinite'], bool):
  print(f"Error: Input file '{inputFile}' does not contain 'infinite' key.")
  sys.exit(1)

# Need layers
if 'layers' not in data or not isinstance(data['layers'], list):
  print(f"Error: Input file '{inputFile}' does not contain 'layers' key.")
  sys.exit(1)

layers = data['layers']
if len(layers) == 0:
  print(f"Error: Input file '{inputFile}' does not contain any layers.")
  sys.exit(1)

# First layer
firstLayer = layers[0]
if 'width' not in firstLayer or 'height' not in firstLayer:
  print(f"Error: First layer in '{inputFile}' does not contain 'width' or 'height' key.")
  sys.exit(1)

if 'chunks' not in firstLayer or not isinstance(firstLayer['chunks'], list):
  print(f"Error: First layer in '{inputFile}' does not contain 'chunks' key.")
  sys.exit(1)

if len(firstLayer['chunks']) == 0:
  print(f"Error: First layer in '{inputFile}' does not contain any chunks.")
  sys.exit(1)

firstLayerFirstChunk = firstLayer['chunks'][0]

inputLayerWidthInTiles = firstLayerFirstChunk['width']
inputLayerHeightInTiles = firstLayerFirstChunk['height']
mapWidthInTiles = firstLayer['width']
mapHeightInTiles = firstLayer['height']
mapWidthInRealChunks =  math.ceil(float(mapWidthInTiles) / float(CHUNK_WIDTH))
mapHeightInRealChunks = math.ceil(float(mapHeightInTiles) / float(CHUNK_HEIGHT))

if inputLayerWidthInTiles < CHUNK_WIDTH or inputLayerHeightInTiles < CHUNK_HEIGHT:
  print(f"Error: Input layer size {inputLayerWidthInTiles}x{inputLayerHeightInTiles} is smaller than chunk size {CHUNK_WIDTH}x{CHUNK_HEIGHT}.")
  sys.exit(1)

# For each output chunk.
worldWidth = 0
worldHeight = 0
chunksDone = set()

for chunkY in range(mapHeightInRealChunks):
  for chunkX in range(mapWidthInRealChunks):
    # Top left X/Y based on real chunk size
    topLeftTileX = chunkX * CHUNK_WIDTH
    topLeftTileY = chunkY * CHUNK_HEIGHT

    # Top left coordinates based on input layer size
    inputTopLeftTileX = math.floor(float(topLeftTileX) / float(inputLayerWidthInTiles)) * inputLayerWidthInTiles
    inputTopLeftTileY = math.floor(float(topLeftTileY) / float(inputLayerHeightInTiles)) * inputLayerHeightInTiles

    chunkLayers = []

    # For each layer...
    for layerIndex, layer in enumerate(layers):
      foundChunk = None
      if 'chunks' not in layer or not isinstance(layer['chunks'], list):
        print(f"Error: Layer {layerIndex} in '{inputFile}' does not contain 'chunks' key.")
        sys.exit(1)

      chunks = layer['chunks']
      for chunk in chunks:
        if 'x' not in chunk or 'y' not in chunk:
          print(f"Error: Chunk in layer {layerIndex} does not contain 'x' or 'y' key.")
          sys.exit(1)

        if chunk['x'] == inputTopLeftTileX and chunk['y'] == inputTopLeftTileY:
          foundChunk = chunk
          break

      if foundChunk is None:
        chunkLayers.append(None)
        continue

      # Is this chunk layer just empty?
      layerEmpty = True
      for tile in foundChunk.get('data', []):
        if tile == 0:
          continue
        layerEmpty = False
        break
      
      if layerEmpty:
        chunkLayers.append(None)
        continue
        
      chunkLayers.append(foundChunk)
      
    # Now we have a chunkLayers list with the found chunks for each layer.
    if all(chunk is None for chunk in chunkLayers) or len(chunkLayers) == 0:
      continue
 
    if len(chunkLayers) > 2:
      print(f"Error: Expected 2 layers for chunk at ({chunkX}, {chunkY}), found {len(chunkLayers)}.")
      sys.exit(1)
    
    def getInputLocalTileX(absoluteTileX):
      return absoluteTileX % inputLayerWidthInTiles
    
    def getInputLocalTileY(absoluteTileY):
      return absoluteTileY % inputLayerHeightInTiles

    layerBase = chunkLayers[0]
    layerBaseData = []
    for y in range(CHUNK_HEIGHT):
      for x in range(CHUNK_WIDTH):
        absoluteTileX = topLeftTileX + x
        absoluteTileY = topLeftTileY + y
        inputLocalTileX = getInputLocalTileX(absoluteTileX)
        inputLocalTileY = getInputLocalTileY(absoluteTileY)
        inputTileIndex = inputLocalTileY * inputLayerWidthInTiles + inputLocalTileX
        outputTileIndex = y * CHUNK_WIDTH + x
        layerBaseData.append(layerBase['data'][inputTileIndex])

    if len(layerBaseData) != CHUNK_TILE_COUNT:
      print(f"Error: Layer base data length {len(layerBaseData)} does not match expected chunk tile count {CHUNK_TILE_COUNT}.")
      sys.exit(1)

    # This is a valid chunk.
    worldWidth = max(worldWidth, chunkX + 1)
    worldHeight = max(worldHeight, chunkY + 1)
    chunksDone.add((chunkX, chunkY))

    chunkHeaderPath = os.path.join(chunksDir, f"chunk_{chunkX}_{chunkY}.h")
    with open(chunkHeaderPath, 'w') as f:
      f.write(f"// Generated chunk header for chunk at position ({chunkX}, {chunkY})\n")
      f.write(f"// Generated at {now}\n")
      f.write("#pragma once\n")
      f.write("#include \"world/chunkdata.h\"\n\n")
      f.write(f"static const chunkdata_t CHUNK_{chunkX}_{chunkY} = {{\n")
      f.write(f"  .layerBase = {{\n")
      for y in range(CHUNK_HEIGHT):
        f.write(f"    ")
        for x in range(CHUNK_WIDTH):
          i = y * CHUNK_WIDTH + x
          byte = layerBaseData[i]
          f.write(f"0x{byte:02x}, ")
        f.write(f"\n")
      f.write("  },\n\n")
      f.write(f"  .layerOverlay = {{}},\n")
      f.write(f"  .entities = {{}},\n")
      f.write("};\n\n")


#     f.write(f"  .entities = {{\n")
#     for entity in entities:
#       if 'id' in entity:
#         entityId = entity['id']
#       else:
#         entityId = entityIdNext
#         entityIdNext += 1

#       if 'type' not in entity:
#         print(f"Error: Entity in chunk ({x}, {y}) does not have 'type' key.")
#         exit(1)

#       if 'x' not in entity or 'y' not in entity:
#         print(f"Error: Entity in chunk ({x}, {y}) does not have 'x' or 'y' key.")
#         exit(1)

#       f.write("    {\n")
#       f.write(f"      .id = {entityId},\n")
#       f.write(f"      .type = {ENTITY_TYPE_MAP.get(entity['type'], 'ENTITY_TYPE_UNKNOWN')},\n"),
#       f.write(f"      .x = {entity['x']},\n")
#       f.write(f"      .y = {entity['y']},\n")
#       f.write(f"    }},\n")
#       pass
#     f.write("  },\n\n")

#     f.write("};\n\n")
#   pass

# Output header file.
headerPath = os.path.join(worldDir, "world.h")
with open(headerPath, 'w') as f:
  f.write(f"// Generated chunks file. Generated at {now}\n\n")
  f.write("#pragma once\n")
  f.write("#include \"dusk.h\"\n")

  # Now, for each chunk, include its header file
  for (x, y) in chunksDone:
    chunk_header = f"world/chunk/chunk_{x}_{y}.h"
    f.write(f"#include \"{chunk_header}\"\n")
  
  f.write("\n")
  f.write(f"#define WORLD_WIDTH {worldWidth}\n")
  f.write(f"#define WORLD_HEIGHT {worldHeight}\n\n")
  f.write(f"static const chunkdata_t* WORLD_CHUNKS[] = {{\n")
  for i in range(worldHeight):
    f.write("  ")
    for j in range(worldWidth):
      if (j, i) in chunksDone:
        f.write(f"&CHUNK_{j}_{i}, ")
      else:
        f.write("NULL, ")
    f.write("\n")
  f.write("};\n\n")

print(f"chunks.h generated at: {headerPath}")