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

shared_path = os.path.abspath(os.path.join(os.path.dirname(__file__), '..', 'shared'))
sys.path.append(shared_path)

from worlddefs import CHUNK_WIDTH, CHUNK_HEIGHT, ENTITY_TYPE_MAP, CHUNK_DATA_DIR

# Dynamically add ../shared to sys.path
shared_path = os.path.abspath(os.path.join(os.path.dirname(__file__), '..', 'shared'))
sys.path.append(shared_path)

# 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')
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")

# Data sent to the world header file
worldWidth = 0
worldHeight = 0
chunksDone = []
entityIdNext = 1

# For each chunk file
for chunkFile in os.listdir(CHUNK_DATA_DIR):
  data = json.load(open(os.path.join(CHUNK_DATA_DIR, chunkFile)))
  print(f"Processing chunk: {chunkFile}")

  if not 'chunk' in data:
    print(f"Error: Chunk file '{chunkFile}' does not contain 'chunk' key.")
    exit(1)

  if not 'position' in data['chunk']:
    print(f"Error: Chunk file '{chunkFile}' does not contain 'position' key.")
    exit(1)
  
  # Position must be array of two integers
  position = data['chunk']['position']
  if not isinstance(position, list) or len(position) != 2:
    print(f"Error: Chunk file '{chunkFile}' has invalid 'position' format.")
    exit(1)
  if not all(isinstance(x, int) for x in position):
    print(f"Error: Chunk file '{chunkFile}' invalid 'position' values.")
    exit(1)

  x, y = position

  # Make sure that the filename "chunk_{x}_{y}.json" matches the position
  expectedFilename = f"chunk_{x}_{y}.json"
  if chunkFile != expectedFilename:
    print(f"Error: Chunk file '{chunkFile}' should be '{expectedFilename}'.")
    exit(1)

  # Chunk should not be already processed
  if (x, y) in chunksDone:
    print(f"Error: Chunk at position ({x}, {y}) is already processed. Skipping.")
    exit(1)
  chunksDone.append((x, y))

  worldWidth = max(worldWidth, x + 1)
  worldHeight = max(worldHeight, y + 1)

  # Read in base layer data
  if 'baseLayer' not in data['chunk']:
    print(f"Error: Chunk file '{chunkFile}' does not contain 'baseLayer' key.")
    exit(1)
  baseLayer = data['chunk']['baseLayer']

  # Base layer should exactly CHUNK_WIDTH * CHUNK_HEIGHT elements
  if len(baseLayer) != CHUNK_HEIGHT:
    print(f"Error: Chunk file '{chunkFile}' has invalid 'baseLayer' length.")
    exit(1)
  for row in baseLayer:
    if len(row) != CHUNK_WIDTH:
      print(f"Error: Chunk file '{chunkFile}' has invalid 'baseLayer' row length.")
      exit(1)

  # Read in overlay layer data
  if 'overlayLayer' not in data['chunk']:
    print(f"Error: Chunk file '{chunkFile}' does not contain 'overlayLayer' key.")
    exit(1)

  overlayLayer = data['chunk']['overlayLayer']

  # Overlay layer should exactly CHUNK_WIDTH * CHUNK_HEIGHT elements
  if len(overlayLayer) != CHUNK_HEIGHT:
    print(f"Error: Chunk file '{chunkFile}' has invalid 'overlayLayer' length.")
    exit(1)
  for row in overlayLayer:
    if len(row) != CHUNK_WIDTH:
      print(f"Error: Chunk file '{chunkFile}' has invalid 'overlayLayer' row length.")
      exit(1)

  # Read in entities
  entities = data['chunk'].get('entities', [])

  # Now we generate a chunk header file
  chunk_header_path = os.path.join(chunksDir, f"chunk_{x}_{y}.h")
  with open(chunk_header_path, 'w') as f:
    f.write(f"// Generated chunk header for chunk at position ({x}, {y})\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_{x}_{y} = {{\n")

    f.write(f"  .layerBase = {{\n")
    for row in baseLayer:
      f.write("    ")
      for column in row:
        f.write(f"0x{column:02x}, ")
      f.write("\n")
    f.write("  },\n\n")

    f.write(f"  .layerOverlay = {{\n")
    for row in overlayLayer:
      f.write("    ")
      for column in row:
        f.write(f"0x{column:02x}, ")
      f.write("\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.
header_path = os.path.join(worldDir, "world.h")
with open(header_path, '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: {header_path}")