"""File operation tools — write_file, read_file, finish."""
from __future__ import annotations

from pathlib import Path

from core.state import PlanStep, StepResult, StepStatus

# All file ops are confined to agent/workspace/
# parents: [0]=tools, [1]=runtime, [2]=agent  → agent/workspace
WORKSPACE_ROOT: Path = Path(__file__).resolve().parents[2] / "workspace"


def write_file(step: PlanStep) -> StepResult:
    """Write content to a file inside agent/workspace/. Path traversal is blocked."""
    rel_path: str = step.payload.get("path", "").strip()
    content: str = step.payload.get("content", "")

    if not rel_path:
        return StepResult(step_id=step.step_id, status=StepStatus.FAILED, error="payload missing 'path'")

    target = (WORKSPACE_ROOT / rel_path).resolve()

    if not str(target).startswith(str(WORKSPACE_ROOT)):
        return StepResult(
            step_id=step.step_id,
            status=StepStatus.FAILED,
            error=f"Path traversal blocked: '{rel_path}' resolves outside workspace",
        )

    target.parent.mkdir(parents=True, exist_ok=True)
    target.write_text(content, encoding="utf-8")

    return StepResult(
        step_id=step.step_id,
        status=StepStatus.DONE,
        output_text=f"Written {len(content)} chars to {rel_path}",
    )


def read_file(step: PlanStep) -> StepResult:
    """Read a file from inside agent/workspace/. Path traversal is blocked."""
    rel_path: str = step.payload.get("path", "").strip()

    if not rel_path:
        return StepResult(step_id=step.step_id, status=StepStatus.FAILED, error="payload missing 'path'")

    target = (WORKSPACE_ROOT / rel_path).resolve()

    if not str(target).startswith(str(WORKSPACE_ROOT)):
        return StepResult(
            step_id=step.step_id,
            status=StepStatus.FAILED,
            error=f"Path traversal blocked: '{rel_path}' resolves outside workspace",
        )

    if not target.exists():
        return StepResult(
            step_id=step.step_id,
            status=StepStatus.FAILED,
            error=f"File not found: {rel_path}",
        )

    content = target.read_text(encoding="utf-8")
    return StepResult(step_id=step.step_id, status=StepStatus.DONE, output_text=content)


def finish_step(step: PlanStep) -> StepResult:
    """Terminal step — signals successful plan completion."""
    return StepResult(step_id=step.step_id, status=StepStatus.DONE, output_text="Agent task complete.")