"""
jobs.py — Build and serialise the jobs.json payload passed to process.py.

The jobs file is the sole interface between the GUI/host Python environment
and the Nuke Python environment.  Keeping it as plain JSON means process.py
has no dependency on this project's other modules.
"""
from __future__ import annotations

import json
from pathlib import Path

from parser import Shot


# ──────────────────────────────────────────────────────────────────────────────
# Public API
# ──────────────────────────────────────────────────────────────────────────────

def build_jobs_payload(shots: list[Shot], template_script: str) -> dict:
    """Return the dict that will be serialised to jobs.json.

    Parameters
    ----------
    shots:
        Shots selected for rendering.
    template_script:
        Absolute path to the Nuke template (.nk) file.
    """
    return {
        "template_script": Path(template_script).as_posix(),
        "jobs": [_shot_to_job(s) for s in shots],
    }


def write_jobs_file(payload: dict, path: str) -> None:
    """Write *payload* to *path* as indented JSON."""
    with open(path, "w", encoding="utf-8") as fh:
        json.dump(payload, fh, indent=2)


def read_jobs_file(path: str) -> dict:
    """Read and return the jobs payload from *path*."""
    with open(path, encoding="utf-8") as fh:
        return json.load(fh)


# ──────────────────────────────────────────────────────────────────────────────
# Internal helpers
# ──────────────────────────────────────────────────────────────────────────────

def _shot_to_job(shot: Shot) -> dict:
    return {
        "basename": shot.basename,
        "input_sequence": shot.input_sequence,
        "first_frame": shot.first_frame,
        "last_frame": shot.last_frame,
        "output_folder": shot.output_folder,
        "output_movie": shot.output_movie,
        "output_exr": shot.output_exr,
    }