import re
from typing import List, Dict, Any, Optional

COMMON_UNITS = [
    "kg", "g", "mg", "l", "liter", "ml", "cl", "el", "tl", "esslöffel", "teelöffel",
    "pck.", "pck", "päckchen", "pkt.", "pkt", "dose", "dosen", "glas", "gläser",
    "prise", "prisen", "msp.", "msp", "messerspitze", "bund", "stk.", "stk",
    "stück", "stücke", "zehe", "zehen", "zweig", "zweige", "blatt", "blätter",
    "scheibe", "scheiben", "stange", "stangen", "kopf", "nest", "nester", "tropfen", "tr."
]

def parse_fraction(val_str: str) -> Optional[float]:
    val_str = val_str.strip()
    if "/" in val_str:
        parts = val_str.split("/")
        if len(parts) == 2:
            try:
                return float(parts[0]) / float(parts[1])
            except ValueError:
                pass
    try:
        return float(val_str.replace(",", "."))
    except ValueError:
        return None

def parse_ingredient_line(line: str) -> Dict[str, Any]:
    raw = line.strip()
    if not raw:
        return {"type": "empty", "raw": ""}
    
    if raw.endswith(":") or raw.lower().startswith("für ") or raw.lower() in [
        "teig", "sauce", "soße", "füllung", "belag", "creme", "glasur", "marinade", "deko",
        "schichten & deko", "keksschicht", "heidelbeersoße", "zitronen-zimt-sirup"
    ]:
        return {
            "type": "header",
            "text": raw.rstrip(":"),
            "raw": raw
        }
    
    match = re.match(r"^(\d+\s+\d+/\d+|\d+/\d+|\d+(?:[.,]\d+)?)(?:\s*-\s*(\d+(?:[.,]\d+)?))?\s*(.*)$", raw)
    if match:
        amt_str = match.group(1).strip()
        range_end = match.group(2)
        rest = match.group(3).strip()
        
        if " " in amt_str and "/" in amt_str:
            whole, frac = amt_str.split()
            val = float(whole) + (parse_fraction(frac) or 0.0)
        elif "/" in amt_str:
            val = parse_fraction(amt_str) or 0.0
        else:
            val = parse_fraction(amt_str) or 0.0
            
        display_amt = f"{amt_str}-{range_end}" if range_end else amt_str
            
        rest_parts = rest.split(None, 1)
        if rest_parts:
            first_word_clean = rest_parts[0].lower().rstrip(".,")
            if first_word_clean in COMMON_UNITS or rest_parts[0].lower() in COMMON_UNITS:
                unit = rest_parts[0]
                ing_name = rest_parts[1] if len(rest_parts) > 1 else ""
                return {
                    "type": "ingredient",
                    "amount_val": val,
                    "amount_str": display_amt,
                    "unit": unit,
                    "name": ing_name,
                    "raw": raw
                }
        
        return {
            "type": "ingredient",
            "amount_val": val,
            "amount_str": display_amt,
            "unit": "",
            "name": rest,
            "raw": raw
        }
        
    return {
        "type": "ingredient",
        "amount_val": None,
        "amount_str": "",
        "unit": "",
        "name": raw,
        "raw": raw
    }

def parse_ingredients_block(text: str) -> List[Dict[str, Any]]:
    lines = [l.strip() for l in (text or "").split("\n") if l.strip()]
    return [parse_ingredient_line(l) for l in lines]

# Test cases
tests = [
    "150 g Mehl",
    "1 EL Zucker",
    "1/2 TL Muskat",
    "1,5 TL Salz",
    "2 frische Eier",
    "2-3 Karotten",
    "Für den Teig:",
    "Salz und Pfeffer nach Belieben",
    "300 ml Milch",
    "1 Pck. Vanillezucker"
]

for t in tests:
    res = parse_ingredient_line(t)
    print(f"'{t}' => {res['type']}: amt={res.get('amount_val')}, unit='{res.get('unit')}', name='{res.get('name') or res.get('text')}'")