#!/usr/bin/env python3
"""Populate clean, disposable paired worktrees with the exact uncommitted integration source."""
import argparse
from pathlib import Path
import shutil
import subprocess
import sys

ROOT = Path(__file__).resolve().parents[2]
sys.path.insert(0, str(ROOT / "tools"))
from campaign import Campaign, ControlError, git_value, source_manifest


def files(root):
    return {name for name in git_value(root, "ls-files", "-z", "--cached", "--others", "--exclude-standard").split("\0") if name}


def main():
    parser = argparse.ArgumentParser(description=__doc__)
    parser.add_argument("--engine-worktree", required=True, type=Path)
    parser.add_argument("--re-worktree", required=True, type=Path)
    args = parser.parse_args()
    campaign = Campaign(str(ROOT))
    contract = campaign.load("controls-bootstrap")
    for kind, target in (("engine", args.engine_worktree), ("re", args.re_worktree)):
        target = target.resolve()
        source = Path(contract["baseline"][kind]["path"])
        if target == source or not str(target).startswith("/tmp/opencode/sots-final-"):
            raise ControlError("only rollout-owned sots-final-* temporary worktrees may be populated")
        if git_value(target, "status", "--porcelain", "--untracked-files=all"):
            raise ControlError("snapshot destination must be clean; never overwrite existing work")
        if git_value(target, "rev-parse", "--path-format=absolute", "--git-common-dir") != git_value(source, "rev-parse", "--path-format=absolute", "--git-common-dir"):
            raise ControlError("destination is not a linked worktree of this repository")
        if git_value(target, "rev-parse", "HEAD") != contract["baseline"][kind]["commit"]:
            raise ControlError("destination baseline mismatch")
        before = source_manifest(source, kind)
        names = files(source)
        for name in files(target) - names:
            path = target / name
            if path.is_file():
                path.unlink()
        for name in names:
            if name.startswith(("campaign/runtime/", "campaign/evidence/")):
                continue
            src, dst = source / name, target / name
            if src.is_symlink():
                raise ControlError("source symlink unsupported")
            if src.is_file():
                dst.parent.mkdir(parents=True, exist_ok=True)
                shutil.copy2(src, dst)
            elif dst.is_file():
                dst.unlink()  # Reproduce tracked source deletions in this disposable tree.
        after, actual = source_manifest(source, kind), source_manifest(target, kind)
        if after != before or actual["sha256"] != before["sha256"]:
            raise ControlError("source changed or copied integration snapshot differs")
        print(f"{kind}: exact integration source {actual['sha256']} at {target}")


if __name__ == "__main__":
    try:
        main()
    except (ControlError, OSError, ValueError, subprocess.SubprocessError) as exc:
        print(str(exc), file=sys.stderr)
        sys.exit(1)