import os
import ezdxf
from ezdxf.math import Vec2

# Hilfsfunktion für Umgebungsvariablen mit Fallback

def check_environment_var(env_str: str, fallback: str) -> str:
    out_path = os.environ.get(env_str)
    if out_path:
        return out_path
    print(f"[WARN] Umgebungsvariable {env_str} ist nicht gesetzt oder leer. Verwende '{fallback}'.")
    return fallback

# Verzeichnisse/Dateien über Umgebungsvariablen oder Fallback
INPUT_DIR = os.path.join(check_environment_var("PROJECT_WORK", "."), "converted_dxfs")
OUTPUT_FILE = os.path.join(check_environment_var("PROJECT_WORK", "."), "block_library.dxf")

doc = ezdxf.new()
msp = doc.modelspace()

def get_bbox(entities):
    min_x, min_y = float('inf'), float('inf')
    max_x, max_y = float('-inf'), float('-inf')
    for e in entities:
        try:
            # Für POLYLINE-Entities: Bounding Box manuell berechnen
            if e.dxftype() == "POLYLINE":
                if hasattr(e, 'vertices') and len(e.vertices) > 0:
                    for vertex in e.vertices:
                        if hasattr(vertex, 'dxf') and hasattr(vertex.dxf, 'location'):
                            x, y = vertex.dxf.location.x, vertex.dxf.location.y
                            min_x, min_y = min(min_x, x), min(min_y, y)
                            max_x, max_y = max(max_x, x), max(max_y, y)
            else:
                # Für andere Entity-Typen: Standard bbox() verwenden
                box = e.bbox()
                if box:
                    (x1, y1), (x2, y2) = box.extmin, box.extmax
                    min_x, min_y = min(min_x, x1), min(min_y, y1)
                    max_x, max_y = max(max_x, x2), max(max_y, y2)
        except Exception as err:
            print(f"    BBox Fehler für {e.dxftype()}: {err}")
            continue
    if min_x == float('inf'):
        return None
    return Vec2((min_x + max_x) / 2, (min_y + max_y) / 2)

x_offset = 0
y_offset = 0
blocks_in_row = 0

for filename in os.listdir(INPUT_DIR):
    if not filename.lower().endswith(".dxf"):
        continue

    filepath = os.path.join(INPUT_DIR, filename)
    name = os.path.splitext(filename)[0]

    try:
        src_doc = ezdxf.readfile(filepath)
        src_msp = src_doc.modelspace()
        entities = list(src_msp)
        allowed_types = {"LINE", "LWPOLYLINE", "POLYLINE", "SPLINE", "CIRCLE", "ARC"}
        filtered_entities = [e for e in entities if e.dxftype() in allowed_types]
        entities = filtered_entities
    except Exception as e:
        print(f"Fehler beim Lesen von {filename}: {e}")
        continue

    center = get_bbox(entities)
    if center is None:
        print(f"Keine gültige Geometrie in {filename}")
        continue

    if name in doc.blocks:
        doc.blocks.delete_block(name)

    blk = doc.blocks.new(name=name, base_point=center)

    for e in entities:
        try:
            blk.add_entity(e.copy())
        except Exception as err:
            print(f"Fehler in {filename}: {err}")

    # Platzierung in Reihen und Spalten
    msp.add_blockref(name, insert=(x_offset, y_offset))
    # Text mit Blocknamen über dem Block
    text_y = y_offset + 150  # 150 Einheiten über dem Block
    msp.add_text(name, dxfattribs={'height': 20, 'insert': (x_offset-150, text_y)})
    blocks_in_row += 1
    x_offset += 350  # Abstand zwischen Blöcken in einer Reihe
    if blocks_in_row == 20:
        blocks_in_row = 0
        x_offset = 0
        y_offset -= 500  # Neue Zeile, nach unten versetzt

print(f"Bibliotheks-DXF gespeichert: {OUTPUT_FILE}")
doc.saveas(OUTPUT_FILE)