from __future__ import annotations

import subprocess
from dataclasses import dataclass
from pathlib import Path

from infra_controller.config import DockerComposeConfig


@dataclass(frozen=True)
class ServiceResult:
    returncode: int
    stdout: str
    stderr: str


class ServiceManager:
    def __init__(self, docker: DockerComposeConfig):
        self._docker = docker

    def service_dir_for_service(self, service_name: str) -> Path:
        return self._docker.base_dir / service_name

    def _resolve_compose_file(self, service_dir: Path) -> Path:
        configured = service_dir / self._docker.compose_file
        if configured.exists():
            return configured

        candidates = list(service_dir.glob("docker-compose*.yml")) + list(service_dir.glob("docker-compose*.yaml"))
        candidates = [p for p in candidates if p.is_file()]

        if not candidates:
            raise FileNotFoundError(
                f"Compose file not found in {service_dir} (expected {self._docker.compose_file} or docker-compose*.yml/.yaml)"
            )

        def rank(p: Path) -> tuple[int, str]:
            name = p.name
            if name == "docker-compose.yml":
                return (0, name)
            if name == "docker-compose.yaml":
                return (1, name)
            if name.endswith(".yml"):
                return (2, name)
            return (3, name)

        return sorted(candidates, key=rank)[0]

    def apply_service(self, service_name: str) -> ServiceResult:
        service_dir = self.service_dir_for_service(service_name)
        if not service_dir.exists():
            raise FileNotFoundError(f"Service directory not found: {service_dir}")

        compose_file = self._resolve_compose_file(service_dir)

        cmd = [
            "docker",
            "compose",
            "-f",
            str(compose_file),
            "up",
            "-d",
        ]

        proc = subprocess.run(cmd, capture_output=True, text=True, cwd=str(service_dir))
        return ServiceResult(returncode=proc.returncode, stdout=proc.stdout, stderr=proc.stderr)