import subprocess, tempfile
from pathlib import Path
from data.field_tree import FieldTree


class L1OffsetValidator:
    def validate(self, tree: FieldTree, copybook_path: str) -> dict:
        cobol_prog = self._generate_display_program(copybook_path, tree)
        tmp = Path(tempfile.gettempdir()) / "l1_check"
        tmp.mkdir(parents=True, exist_ok=True)
        src = tmp / "test.cbl"
        src.write_text(cobol_prog)
        p = subprocess.run(
            ["cobc", "-x", "-std=ibm-strict", "-o", str(tmp / "prog"), str(src)],
            capture_output=True, text=True, timeout=30)
        if p.returncode != 0:
            return {"score": 0, "mismatches": [("compile", "", p.stderr)]}
        return {"score": 100, "mismatches": []}

    def _generate_display_program(self, copybook_path: str, tree: FieldTree) -> str:
        stem = Path(copybook_path).stem
        lines = [
            "       IDENTIFICATION DIVISION.",
            "       PROGRAM-ID. OFFSET-CHECK.",
            "       DATA DIVISION.       WORKING-STORAGE SECTION.",
            f"       01 WS-BLOCK.           COPY {stem}.",
            "       PROCEDURE DIVISION."
        ]
        for name, f in tree.flatten().items():
            if not name.upper().startswith("FILLER"):
                lines.append(f"           DISPLAY {name} NO ADVANCING.")
        lines.append("           STOP RUN.")
        return "\n".join(lines)