"""SFTP push/pull of local app folders. Never delete remote extras."""

from __future__ import annotations

from collections.abc import Callable
from pathlib import Path

from gpu_rent.config import Config
from gpu_rent.payload import has_payload, iter_payload_files, model_push_set, sha256_file
from gpu_rent.ssh_ops import (
    get_file_on,
    open_ssh,
    put_file_on,
    remote_sha256_on,
    run_ssh_on,
)

Log = Callable[[str], None]


def push_tree(
    cfg: Config,
    host: str,
    local_root: Path,
    remote_root: str,
    log: Log,
    *,
    models: bool,
) -> int:
    if not has_payload(local_root):
        log(f"push {local_root.name}: пусто — skip")
        return 0
    files = model_push_set(local_root) if models else iter_payload_files(local_root)
    file_list = list(files)
    total = len(file_list)
    sent = 0
    skipped = 0
    client = open_ssh(cfg, host)
    try:
        for i, path in enumerate(file_list, start=1):
            rel = path.relative_to(local_root).as_posix()
            remote = f"{remote_root.rstrip('/')}/{rel}"
            local_hash = sha256_file(path)
            remote_hash = remote_sha256_on(client, remote)
            if remote_hash and remote_hash.lower() == local_hash.lower():
                skipped += 1
                continue
            log(f"push [{i}/{total}] {rel}")
            put_file_on(client, path, remote)
            sent += 1
    finally:
        client.close()
    if sent == 0:
        log(f"push {local_root.name}: всё уже на VM ({total} файл(ов), skip={skipped})")
    else:
        log(f"push {local_root.name}: {sent}/{total} отправлено (skip={skipped})")
    return sent


def pull_tree(cfg: Config, host: str, remote_root: str, local_root: Path, log: Log) -> int:
    client = open_ssh(cfg, host)
    try:
        listing = run_ssh_on(
            client,
            f"find {remote_root} -type f 2>/dev/null | sed 's|^{remote_root}/||'",
            check=False,
            timeout=120,
        )
        names = [line.strip() for line in listing.splitlines() if line.strip()]
        work = [
            rel
            for rel in names
            if not (
                rel.endswith("/.gitkeep")
                or rel.rsplit("/", 1)[-1] in {".gitkeep", "README.md"}
            )
        ]
        total = len(work)
        pulled = 0
        skipped = 0
        for i, rel in enumerate(work, start=1):
            remote = f"{remote_root.rstrip('/')}/{rel}"
            local = local_root / rel
            remote_hash = remote_sha256_on(client, remote)
            if local.is_file() and remote_hash and sha256_file(local).lower() == remote_hash.lower():
                skipped += 1
                continue
            log(f"pull [{i}/{total}] {rel}")
            get_file_on(client, remote, local)
            pulled += 1
    finally:
        client.close()
    if pulled:
        log(f"pull Output: {pulled}/{total} (skip={skipped})")
    else:
        log(f"pull Output: нечего забирать ({total} файл(ов), skip={skipped})")
    return pulled