from __future__ import annotations

import os
import subprocess
import time
from pathlib import Path

from utils.cache.render import ROLE_DIR as CACHE_ROLE_DIR
from utils.cache.render import render_artifacts
from utils.env.handlers.infinito.cache.conf import KEY as CACHE_CONF_KEY
from utils.env.handlers.infinito.cache.conf import RELATIVE as CACHE_CONF

from .coredns import CoreDNSCorefileRenderer
from .env import compose_file_args
from .network import detect_outer_network_mtu
from .proc import run_streaming
from .profile import Profile
from .runner_mirror import env_image

CACHE_ROLE_SHELL_DIR = CACHE_ROLE_DIR / "files" / "shell"

INIT_IMAGE_KEY = "INFINITO_CACHE_PACKAGE_FRONTEND_INIT_IMAGE"


class Compose:
    """Wrapper around `docker compose` for the dev/CI stack."""

    def __init__(self, repo_root: Path, distro: str) -> None:
        self.repo_root = repo_root
        self.distro = distro
        self.profile = Profile()

    def _base_env(self) -> dict[str, str]:
        env = dict(os.environ)
        env["INFINITO_DISTRO"] = self.distro
        outer_network_mtu = detect_outer_network_mtu(env)
        if outer_network_mtu:
            env["INFINITO_OUTER_NETWORK_MTU"] = outer_network_mtu
        if not env.get("INFINITO_IMAGE"):
            local_image_script = (
                self.repo_root / "scripts" / "meta" / "resolve" / "image" / "local.sh"
            )
            result = subprocess.run(
                [str(local_image_script)],
                cwd=self.repo_root,
                env=env,
                capture_output=True,
                text=True,
                check=True,
            )
            env["INFINITO_IMAGE"] = result.stdout.strip()
        return env

    def run(
        self,
        args: list[str],
        *,
        check: bool = True,
        capture: bool = False,
        live: bool = False,
        text: bool = True,
        extra_env: dict[str, str] | None = None,
    ) -> subprocess.CompletedProcess:
        cmd = ["docker", "compose", *compose_file_args(), *args]
        env = self._base_env()
        if extra_env:
            env.update({k: str(v) for k, v in extra_env.items()})

        if live:
            r = run_streaming(cmd, cwd=self.repo_root, env=env, text=text)
        else:
            r = subprocess.run(
                cmd,
                cwd=self.repo_root,
                env=env,
                check=False,
                capture_output=capture,
                text=text,
            )

        if check and int(r.returncode) != 0:
            raise subprocess.CalledProcessError(
                int(r.returncode), cmd, output=r.stdout, stderr=r.stderr
            )

        return r

    def _compose_up_with_retries(
        self,
        args: list[str],
        *,
        attempts: int = 6,
        delay_s: int = 30,
    ) -> None:
        """Retry compose up to mitigate transient registry errors."""
        last_exc: Exception | None = None

        for i in range(1, int(attempts) + 1):
            try:
                self.run(args, check=True)
            except Exception as exc:
                last_exc = exc

                if i >= int(attempts):
                    raise

                print(
                    f">>> WARNING: compose up failed (attempt {i}/{attempts}): {exc}\n"
                    f">>> Retrying in {int(delay_s)}s..."
                )
                time.sleep(int(delay_s))
            else:
                return

        if last_exc is not None:
            raise last_exc

    def _bootstrap_package_cache(self, env: dict[str, str]) -> None:
        """Run the host-side Nexus bootstrap helper. Idempotent."""
        helper = CACHE_ROLE_SHELL_DIR / "bootstrap.sh"
        print(">>> Bootstrapping package-cache proxy repos")
        r = subprocess.run(
            [str(helper)],
            cwd=self.repo_root,
            env=env,
            check=False,
            text=True,
        )
        if r.returncode != 0:
            print(
                f">>> WARNING: package-cache bootstrap exited rc={r.returncode}; "
                f"re-run {helper} manually or inspect docker logs infinito-package-cache"
            )

    def _generate_package_frontend_certs(self, env: dict[str, str]) -> None:
        """Generate frontend CA + leaf certs before nginx starts."""
        helper = CACHE_ROLE_SHELL_DIR / "certs.sh"
        if self.profile.image_mirror_enabled():
            env = {
                **env,
                INIT_IMAGE_KEY: env_image(self.repo_root, INIT_IMAGE_KEY),
            }
        print(">>> Generating package-cache-frontend CA + per-hostname certs")
        subprocess.run(
            [str(helper)],
            cwd=self.repo_root,
            env=env,
            check=True,
            text=True,
        )

    def _apply_shared_cache(self, env: dict[str, str]) -> None:
        """Serve this checkout's cache declarations from the shared stack.

        The owner creates the proxy repositories and the certificates while
        it brings its own containers up. An instance that only joins the
        network starts none of them, so without this its `cache:` entries
        exist on disk and nowhere else: the hijacked hostname resolves to a
        frontend that has no server block for it.
        """
        helper = self.repo_root / "scripts" / "system" / "cache" / "apply.sh"
        print(">>> Applying this checkout's cache declarations to the shared stack")
        r = subprocess.run(
            ["bash", str(helper)],
            cwd=self.repo_root,
            env=env,
            check=False,
            text=True,
        )
        if r.returncode != 0:
            print(
                f">>> WARNING: cache apply exited rc={r.returncode}; the shared "
                "frontend keeps serving the map it already had. Start the owning "
                f"stack and re-run `make cache-apply` ({helper})."
            )

    def _install_package_frontend_ca_in_runner(self) -> None:
        """Install the frontend CA in the runner trust store. Idempotent."""
        print(">>> Installing package-cache-frontend CA into runner trust store")
        r = self.exec(
            ["sh", "-lc", "/usr/local/bin/package-frontend-ca.sh"],
            check=False,
            live=False,
        )
        if r.returncode != 0:
            print(
                ">>> WARNING: package-frontend-ca installer exited "
                f"rc={r.returncode}; cache TLS via DNS-hijack may fail. "
                "Re-run /usr/local/bin/package-frontend-ca.sh inside the "
                "runner manually."
            )

    def _render_coredns_corefile(self) -> None:
        renderer = CoreDNSCorefileRenderer(repo_root=self.repo_root)
        out = renderer.render(show_preview=True, preview_lines=25)
        print(f"[compose] Corefile generated at: {out}")
        print(
            f"[compose] Corefile exists={out.exists()} "
            f"size={out.stat().st_size if out.exists() else 'n/a'}"
        )

    def _render_cache_artifacts(self) -> None:
        """Render the generated cache files the overrides mount.

        `make dotenv` renders them too, but `scripts/meta/env/load.sh` only
        auto-generates `.env` — it runs on the bare bootstrap python, which
        has no Jinja. Without this, a checkout that never ran `make dotenv`
        reaches `extends: compose.cache-consumer.yml` with the file absent.
        """
        conf = Path(os.environ.get(CACHE_CONF_KEY, "") or (self.repo_root / CACHE_CONF))
        for path in render_artifacts(self.repo_root, conf):
            print(f"[compose] cache file generated at: {path}")

    def up(self, *, run_entry_init: bool = True) -> None:
        print(">>> Rendering the derived cache files from the cache: declarations")
        self._render_cache_artifacts()

        print(">>> Rendering CoreDNS Corefile from template")
        self._render_coredns_corefile()

        print(">>> Starting compose stack (coredns + infinito)")
        env = self._base_env()
        keys = [
            "INFINITO_BUILD",
            "INFINITO_DISTRO",
            "INFINITO_IMAGE",
            "INFINITO_IMAGE_TAG",
            "INFINITO_PULL_POLICY",
            "GITHUB_SHA",
        ]
        print(">>> env:", {k: env.get(k) for k in keys})
        print(">>> NIX_CONFIG:", "<set>" if env.get("NIX_CONFIG") else "<empty>")

        no_build = env["INFINITO_BUILD"] != "1"
        args: list[str] = ["up", "-d"]
        if no_build:
            args.append("--no-build")
        if self.profile.owns_cache_stack():
            self._generate_package_frontend_certs(env)
            args += ["registry-cache", "package-cache", "package-cache-frontend"]
        args += ["coredns", "infinito"]

        self._compose_up_with_retries(args, attempts=6, delay_s=30)

        self.wait_for_healthy()

        if self.profile.owns_cache_stack():
            self._bootstrap_package_cache(env)
        elif self.profile.cache_stack_enabled():
            self._apply_shared_cache(env)
        if self.profile.cache_stack_enabled():
            self._install_package_frontend_ca_in_runner()

        if run_entry_init:
            print(">>> Running infinito entry.sh init")
            src_dir = os.environ["INFINITO_SRC_DIR"]
            r = self.exec(
                ["sh", "-lc", f"{src_dir}/scripts/docker/entry.sh true"],
                workdir=src_dir,
                check=False,
                live=True,
                extra_env={
                    "ANSIBLE_FORCE_COLOR": "1",
                    "PY_COLORS": "1",
                    "TERM": "xterm-256color",
                },
            )

            if r.returncode != 0:
                raise RuntimeError(f"entry.sh init failed (rc={r.returncode})")

    def down(self) -> None:
        """Tear down the stack."""
        from .down import down_stack

        down_stack(repo_root=self.repo_root, distro=self.distro)

    def exec(
        self,
        cmd: list[str],
        *,
        check: bool = True,
        workdir: str | None = None,
        capture: bool = False,
        live: bool = False,
        tty: bool | None = None,
        extra_env: dict[str, str] | None = None,
    ) -> subprocess.CompletedProcess:
        """Execute inside the infinito container.

        tty=None auto-selects (local: True, CI: False).
        live=True streams stdout/stderr.
        """
        if tty is None:
            tty = not self.profile.is_ci()

        args = ["exec"]
        if not tty:
            args.append("-T")

        if workdir:
            args += ["-w", workdir]

        if extra_env:
            for k, v in extra_env.items():
                args += ["-e", f"{k}={v}"]

        args += ["infinito", *cmd]

        return self.run(
            args,
            check=check,
            capture=capture,
            live=live,
        )

    def _get_infinito_container_id(self) -> str:
        r = self.run(["ps", "-q", "infinito"], capture=True, check=True)
        cid = (r.stdout or "").strip()

        if not cid:
            raise RuntimeError(
                "infinito container not found (docker compose ps -q infinito returned empty)"
            )

        return cid

    def wait_for_healthy(self, *, timeout_s: int | None = None) -> None:
        """Wait for the infinito container's healthcheck."""
        if timeout_s is None:
            timeout_s = int(os.environ["INFINITO_WAIT_HEALTH_TIMEOUT_S"])

        print(">>> Waiting for infinito container to become healthy")

        cid = self._get_infinito_container_id()
        start = time.time()

        while True:
            r = subprocess.run(
                ["docker", "inspect", "-f", "{{.State.Health.Status}}", cid],
                cwd=self.repo_root,
                capture_output=True,
                text=True,
                check=False,
            )

            status = r.stdout.strip() if r.returncode == 0 else ""

            if status == "healthy":
                print(">>> infinito container is healthy")
                return

            if status == "unhealthy":
                print(">>> infinito container is unhealthy")

            if (time.time() - start) > timeout_s:
                print(
                    ">>> ERROR: infinito container not healthy, dumping last 200 log lines\n"
                )

                logs = self.exec(
                    ["sh", "-lc", "journalctl -n 200 --no-pager || true"],
                    check=False,
                    capture=True,
                )

                print("===== journalctl (last 200 lines) =====")
                print(logs.stdout or "<no output>")
                print("======================================\n")

                docker_logs = subprocess.run(
                    ["docker", "logs", "--tail", "200", cid],
                    cwd=self.repo_root,
                    capture_output=True,
                    text=True,
                    check=False,
                )

                print("===== docker logs (last 200 lines) =====")
                print(docker_logs.stdout or "<no output>")
                print("=======================================\n")

                raise RuntimeError(
                    f"infinito container not healthy after {timeout_s}s "
                    f"(last status: {status})"
                )

            time.sleep(2)