from flask import (
    Flask, render_template, request,
    send_file, abort, redirect, url_for
)
import subprocess
import uuid
from pathlib import Path
from datetime import datetime
import zipfile
import yaml   # ⭐ 추가

app = Flask(__name__, static_folder="static")

BASE = Path("/work")
BASE.mkdir(exist_ok=True)


def ts():
    return datetime.now().strftime("%Y-%m-%d-%H-%M-%S")


# ===== backup YAML sanitize =====

REMOVE_METADATA_FIELDS = {
    "uid",
    "resourceVersion",
    "generation",
    "creationTimestamp",
    "managedFields",
}

def sanitize_backup_yaml(path: Path):
    docs = list(yaml.safe_load_all(path.read_text()))
    cleaned = []

    for doc in docs:
        if not isinstance(doc, dict):
            cleaned.append(doc)
            continue

        # metadata 정리
        meta = doc.get("metadata")
        if isinstance(meta, dict):
            for k in list(meta.keys()):
                if k in REMOVE_METADATA_FIELDS:
                    meta.pop(k, None)

        # status 제거 (rollback 충돌 방지)
        doc.pop("status", None)

        cleaned.append(doc)

    path.write_text(
        yaml.safe_dump_all(
            cleaned,
            sort_keys=False
        )
    )


def sanitize_backup_tree(backup_dir: Path):
    if not backup_dir.exists():
        return

    for p in backup_dir.rglob("*.yaml"):
        sanitize_backup_yaml(p)


# ===== routes =====

@app.route("/", methods=["GET", "POST"])
def index():
    if request.method == "POST":
        job_id = str(uuid.uuid4())
        job_dir = BASE / job_id
        job_dir.mkdir(parents=True, exist_ok=True)

        cmd = [
            "python3",
            "/app/migrator.py",
            "--split",
            "--mapping", "/app/mapping.yaml",
        ]

        if request.form.get("from_class"):
            cmd += ["--from-ingress-class", request.form["from_class"]]
        if request.form.get("to_class"):
            cmd += ["--ingress-class", request.form["to_class"]]
        if request.form.get("namespace"):
            cmd += ["--namespace", request.form["namespace"]]

        subprocess.check_call(cmd, cwd=job_dir)

        # 🔥 backup YAML 정화
        sanitize_backup_tree(job_dir / "backup")

        timestamp = ts()
        result_zip = BASE / f"{timestamp}-result.zip"
        backup_zip = BASE / f"{timestamp}-backup.zip"

        # result zip
        with zipfile.ZipFile(result_zip, "w", zipfile.ZIP_DEFLATED) as z:
            for p in (job_dir / "yaml").rglob("*"):
                if p.is_file():
                    z.write(p, p.relative_to(job_dir))
            report = job_dir / "migration-report.md"
            if report.exists():
                z.write(report, report.relative_to(job_dir))

        # backup zip
        with zipfile.ZipFile(backup_zip, "w", zipfile.ZIP_DEFLATED) as z:
            for p in (job_dir / "backup").rglob("*"):
                if p.is_file():
                    z.write(p, p.relative_to(job_dir))

        return redirect(url_for(
            "preview",
            job_id=job_id,
            result_zip=result_zip.name,
            backup_zip=backup_zip.name
        ))

    return render_template("index.html")


@app.route("/preview/<job_id>/<result_zip>/<backup_zip>")
def preview(job_id, result_zip, backup_zip):
    job_dir = BASE / job_id

    def tree(root):
        t = {}
        if root.exists():
            for ns in root.iterdir():
                if ns.is_dir():
                    t[ns.name] = sorted(
                        f.name for f in ns.iterdir() if f.is_file()
                    )
        return t

    return render_template(
        "preview.html",
        job_id=job_id,
        yaml_tree=tree(job_dir / "yaml"),
        backup_tree=tree(job_dir / "backup"),
        result_zip=result_zip,
        backup_zip=backup_zip,
    )


@app.route("/view/<job_id>/<kind>/<path:path>", methods=["GET", "POST"])
def view_file(job_id, kind, path):
    if kind not in ("yaml", "backup"):
        abort(404)

    f = BASE / job_id / kind / path
    if not f.exists() or not f.is_file():
        abort(404)

    editable = (kind == "yaml")

    if request.method == "POST":
        if not editable:
            abort(403)

        f.write_text(request.form.get("content", ""))
        return redirect(url_for(
            "view_file",
            job_id=job_id,
            kind=kind,
            path=path
        ))

    return render_template(
        "view.html",
        title=f"{kind.upper()} / {path}",
        content=f.read_text(),
        editable=editable
    )


@app.route("/report/<job_id>")
def view_report(job_id):
    report = BASE / job_id / "migration-report.md"
    if not report.exists():
        abort(404)

    return render_template(
        "view.html",
        title="Migration Report",
        content=report.read_text()
    )


@app.route("/apply/<job_id>/<kind>", methods=["POST"])
def apply_yaml(job_id, kind):
    if kind not in ("yaml", "backup"):
        abort(400)

    target_dir = BASE / job_id / kind
    if not target_dir.exists():
        abort(404)

    if kind == "yaml":
        cmd = ["kubectl", "replace", "-f", str(target_dir), "--recursive"]
        title = "Replace Converted YAML"
    else:
        cmd = ["kubectl", "replace", "-f", str(target_dir), "--recursive"]
        title = "Rollback from Backup"

    proc = subprocess.run(
        cmd,
        stdout=subprocess.PIPE,
        stderr=subprocess.PIPE,
        text=True
    )

    output = ""
    if proc.stdout:
        output += proc.stdout
    if proc.stderr:
        output += "\n" + proc.stderr

    status = "SUCCESS" if proc.returncode == 0 else "FAILED"

    return render_template(
        "apply_result.html",
        title=title,
        status=status,
        command=" ".join(cmd),
        output=output
    )


@app.route("/download/<name>")
def download(name):
    path = BASE / name
    if not path.exists():
        abort(404)
    return send_file(path, as_attachment=True)


if __name__ == "__main__":
    app.run(host="0.0.0.0", port=8080, debug=False)