import json
from data.field_tree import FieldTree, Field
from agents.llm import LLMClient

P1 = "You are a COBOL COPYBOOK parser. Output JSON: {\"fields\":[{\"name\":\"...\",\"level\":N,\"pic\":\"...\",\"usage\":\"DISPLAY|COMP-3|COMP\",\"offset\":N,\"length\":N,\"decimal\":N,\"signed\":bool,\"occurs\":N|null,\"redefines\":\"...\"|null,\"conditions\":[{\"name\":\"...\",\"value\":\"...\"}],\"children\":[...]}]} Return JSON only."


class Agent1Parser:
    def __init__(self, llm: LLMClient):
        self.llm = llm

    def parse(self, text: str) -> FieldTree:
        r = self.llm.call([{"role": "system", "content": P1}, {"role": "user", "content": text}])
        try:
            return self._load(json.loads(r))
        except:
            return FieldTree(copybook_name="parse_error")

    def _load(self, d):
        return FieldTree(fields=self._fields(d.get("fields", []), 0))

    def _fields(self, raw, off):
        result = []
        cur = off
        for rf in raw:
            f = Field(name=rf.get("name", ""), level=rf.get("level", 0), pic=rf.get("pic", ""),
                      usage=rf.get("usage", "DISPLAY"), offset=cur, length=rf.get("length", 0),
                      decimal=rf.get("decimal", 0), signed=rf.get("signed", False),
                      occurs=rf.get("occurs"), redefines=rf.get("redefines"),
                      conditions=rf.get("conditions", []))
            f.children = self._fields(rf.get("children", []), cur)
            cur += f.length
            result.append(f)
        return result