import logging
import subprocess

from pathlib import Path
from datetime import datetime, UTC

from config import *
from git import run_git_cmd, ensure_git_repo
from technitium import list_zones, export_zone

def write_zone_export(zone_name, content) -> Path:
    dest_dir = Path(GIT_REPO_DIR)
    dest_dir.mkdir(parents=True, exist_ok=True)
    safe_name = zone_name.replace("/", "_")
    out_path = dest_dir / f"db.{safe_name}"
    mode = "w"
    logging.info(f"Writing export for zone {zone_name} -> {out_path}")
    with open(out_path, mode, encoding="utf-8") as f:
        f.write(content)
    return out_path

def commit_and_push(changed_files, trigger_path):
    # Stage files
    try:
        # Add only the exports folder (keeps repo tidy)
        run_git_cmd(["add", "-A"])
    except subprocess.CalledProcessError as e:
        logging.exception(f"git add failed: {e}")
        return

    # Check if there is anything to commit
    try:
        # git diff --cached --quiet will exit 0 if no changes staged
        subprocess.run(["git", "-C", GIT_REPO_DIR, "diff", "--cached", "--quiet"], check=True)
        logging.info("No changes to commit (nothing staged).")
        return
    except subprocess.CalledProcessError:
        # Non-zero return means there are changes staged.
        pass

    changed_list_text = "\n".join(str(p) for p in changed_files)
    ts = datetime.now(UTC).strftime("%Y-%m-%dT%H:%M:%SZ")
    commit_msg = f"Technitium zone export: {ts}\n\nTrigger: {trigger_path}\n\nChanged files:\n{changed_list_text}\n"
    env = os.environ.copy()
    env["GIT_AUTHOR_NAME"] = GIT_AUTHOR_NAME
    env["GIT_AUTHOR_EMAIL"] = GIT_AUTHOR_EMAIL
    try:
        run_git_cmd(["commit", "-m", commit_msg], check=True)
        logging.info("Committed changes to git.")
    except subprocess.CalledProcessError as e:
        logging.exception(f"git commit failed: {e}")
        return

    if GIT_PUSH:
        try:
            run_git_cmd(["push"], check=True)
            logging.info("Pushed commit to remote.")
        except subprocess.CalledProcessError as e:
            logging.exception(f"git push failed: {e}")

def extract_domain_from_path(path: str) -> str|None:
    name = Path(path).name
    name_no_ext = name.rstrip(".zone")

    candidates = set()

    if DOMAIN_FRAGMENT_RE.search(name_no_ext):
        found = DOMAIN_FRAGMENT_RE.findall(name_no_ext)
        for f in found:
            return f

    return None

def export_single_zone(trigger_path: str) -> list[Path]:
    logging.info(f"Starting export of single zone for trigger path {trigger_path})")
    ensure_git_repo()
    domain = extract_domain_from_path(trigger_path)

    try:
        zones = list_zones()
    except Exception as e:
        logging.exception(f"Failed to list zones from API; falling back to full export: {e}")
        return export_all_zones(trigger_path)

    if domain is not None:
        for zone in zones:
            zone_name = zone.get("name")
            if zone_name == domain:
                logging.info(f"Single matching zone found: {zone_name}")
                try:
                    content = export_zone(zone)
                    out = write_zone_export(zone_name, content)
                    commit_and_push([out], trigger_path)
                    return [out]
                except Exception as e:
                    logging.exception(f"Failed to export zone {zone_name}; falling back to full export: {e}")
                    return export_all_zones(trigger_path)

        logging.info(f"No unique match found for {domain}; falling back to full export")
        return export_all_zones(trigger_path)

    else:
        logging.info(f"No domain found for trigger path {trigger_path}; falling back to full export")
        return export_all_zones(trigger_path)

def export_all_zones(trigger_path: str ="filesystem-change") -> list[Path]:
    logging.info(f"Starting export of all zones (trigger={trigger_path})")
    ensure_git_repo()

    try:
        zones = list_zones()
    except Exception as e:
        logging.exception(f"Failed to list zones from API: {e}")
        return []

    written_files = []
    for z in zones:
        # zone may be a dict with keys like 'id' and 'domain' — adapt to your API result shape
        zone_name = z.get("name")
        try:
            content = export_zone(z)
            out = write_zone_export(zone_name, content)
            written_files.append(out)
        except Exception as e:
            logging.exception(f"Failed to export zone {zone_name}: {e}")

    if written_files:
        commit_and_push(written_files, trigger_path)
    else:
        logging.info("No zone files were written; skipping commit.")

    return written_files