#!/usr/bin/env python3
import argparse
import subprocess
from copy import deepcopy
from pathlib import Path
from collections import defaultdict

from ruamel.yaml import YAML
from ruamel.yaml.comments import CommentedMap


# -----------------------------
# YAML 설정
# -----------------------------
yaml = YAML()
yaml.preserve_quotes = True
yaml.indent(mapping=2, sequence=4, offset=2)


# -----------------------------
# kubectl ingress 조회
# -----------------------------
def kubectl_ingress():
    out = subprocess.check_output(
        ["kubectl", "get", "ingress", "--all-namespaces", "-o", "yaml"]
    )
    return yaml.load(out)


# -----------------------------
# mapping.yaml 로드
# -----------------------------
def load_mapping(path):
    with open(path) as f:
        return yaml.load(f)


# -----------------------------
# ingress 변환 로직
# -----------------------------
def migrate_ingress(data, mapping, ingress_class=None):
    report = {
        "converted": [],
        "partial": [],
        "unsupported": [],
        "detail": defaultdict(lambda: {"partial": [], "unsupported": []}),
    }

    new = deepcopy(data)

    for item in new.get("items", []):
        meta = item.setdefault("metadata", {})
        spec = item.setdefault("spec", {})

        name = meta.get("name")
        namespace = meta.get("namespace", "default")
        ingress_id = f"{namespace}/{name}"

        if ingress_class:
            spec["ingressClassName"] = ingress_class

        anns = meta.get("annotations", {}) or {}
        new_anns = CommentedMap()

        for k, v in anns.items():
            if k in mapping:
                rule = mapping[k]
                support = rule.get("support", "unsupported")
                haproxy_key = rule.get("haproxy")

                if support == "full":
                    new_anns[haproxy_key] = v
                    report["converted"].append(k)

                elif support == "partial":
                    new_anns[haproxy_key] = v
                    note = rule.get("note", "")
                    new_anns.yaml_set_comment_before_after_key(
                        haproxy_key,
                        before=f"PARTIAL SUPPORT: {note}",
                    )
                    report["partial"].append(k)
                    report["detail"][ingress_id]["partial"].append(
                        {
                            "nginx": k,
                            "haproxy": haproxy_key,
                            "note": note,
                        }
                    )

                else:
                    lines = [f"UNSUPPORTED {k}:"]
                    for line in str(v).splitlines():
                        lines.append(f"  {line}")
                    new_anns.yaml_set_end_comment("\n".join(lines))

                    report["unsupported"].append(k)
                    report["detail"][ingress_id]["unsupported"].append(
                        {
                            "nginx": k,
                            "value": v,
                        }
                    )
            else:
                new_anns[k] = v

        meta["annotations"] = new_anns

    return new, report


# -----------------------------
# 리포트 생성 (Markdown)
# -----------------------------
def write_report(report, path):
    with open(path, "w") as f:
        f.write("# Ingress Migration Report\n\n")
        f.write("## Summary\n")
        f.write(f"- Converted  : {len(report['converted'])}\n")
        f.write(f"- Partial    : {len(report['partial'])}\n")
        f.write(f"- Unsupported: {len(report['unsupported'])}\n\n")
        f.write("---\n\n")

        if any(v["partial"] for v in report["detail"].values()):
            f.write("## ⚠️ Partial Support\n\n")
            for ingress, items in report["detail"].items():
                if not items["partial"]:
                    continue
                f.write(f"### {ingress}\n")
                for p in items["partial"]:
                    f.write(
                        f"- {p['nginx']}\n"
                        f"  - mapped to: {p['haproxy']}\n"
                        f"  - note: {p['note']}\n"
                    )
                f.write("\n")

        if any(v["unsupported"] for v in report["detail"].values()):
            f.write("## ❌ Unsupported\n\n")
            for ingress, items in report["detail"].items():
                if not items["unsupported"]:
                    continue
                f.write(f"### {ingress}\n")
                for u in items["unsupported"]:
                    f.write(f"- {u['nginx']}\n")
                    f.write("  ```nginx\n")
                    f.write(f"{u['value']}\n")
                    f.write("  ```\n")
                f.write("\n")


# -----------------------------
# 파일 저장
# -----------------------------
def save_single(data, out_path):
    with open(out_path, "w") as f:
        yaml.dump(data, f)


def save_split(data, out_dir):
    Path(out_dir).mkdir(parents=True, exist_ok=True)
    for item in data.get("items", []):
        name = item["metadata"]["name"]
        namespace = item["metadata"].get("namespace", "default")
        path = Path(out_dir) / f"{namespace}__{name}.yaml"
        with open(path, "w") as f:
            yaml.dump(item, f)


# -----------------------------
# main
# -----------------------------
def main():
    parser = argparse.ArgumentParser(
        description="nginx ingress → HAProxy ingress migration utility"
    )
    parser.add_argument("--mapping", default="mapping.yaml")
    parser.add_argument("--single", action="store_true")
    parser.add_argument("--split", action="store_true")
    parser.add_argument("--out", default="output")
    parser.add_argument("--ingress-class")
    parser.add_argument(
        "--report",
        default="migration-report.md",
        help="migration summary report file",
    )

    args = parser.parse_args()

    if not args.single and not args.split:
        parser.error("one of --single or --split must be specified")

    ingress = kubectl_ingress()
    mapping = load_mapping(args.mapping)

    converted, report = migrate_ingress(
        ingress,
        mapping,
        ingress_class=args.ingress_class,
    )

    if args.single:
        out_file = args.out if args.out.endswith(".yaml") else f"{args.out}.yaml"
        save_single(converted, out_file)

    if args.split:
        save_split(converted, args.out)

    write_report(report, args.report)

    print("\n=== Migration Summary ===")
    print(f"Converted  : {len(report['converted'])}")
    print(f"Partial    : {len(report['partial'])}")
    print(f"Unsupported: {len(report['unsupported'])}")
    print(f"Report     : {args.report}")


if __name__ == "__main__":
    main()