"""End-to-end test for `flow dotfiles` against the example repo.

Gated by FLOW_RUN_E2E=1 because it builds and runs a container image.
Tries podman first, falls back to docker. Skips if neither is available.
"""

from __future__ import annotations

import os
import shutil
import subprocess
from pathlib import Path
import textwrap

import pytest


REPO_ROOT = Path(__file__).resolve().parents[2]
CONTAINERFILE = Path(__file__).parent / "Containerfile"
EXAMPLE_DIR = REPO_ROOT / "example"
IMAGE_TAG = "flow-e2e:test"


def _pick_runtime() -> str | None:
    for binary in ("podman", "docker"):
        if not shutil.which(binary):
            continue
        result = subprocess.run(
            [binary, "version"],
            capture_output=True,
            text=True,
        )
        if result.returncode == 0:
            return binary
    return None


def _flow_script(*commands: str) -> str:
    """Build a reusable flow sandbox script for container execution."""
    return textwrap.dedent(
        """
        set -euo pipefail

        export XDG_CONFIG_HOME="/tmp/flow-config"
        export XDG_DATA_HOME="/tmp/flow-data"
        export XDG_STATE_HOME="/tmp/flow-state"
        export TARGET_HOSTNAME="flow-e2e"
        export USER_EMAIL="e2e@example.com"
        export PYTHONPATH="/opt/flow-src/src:${PYTHONPATH:-}"

        rm -rf "$XDG_CONFIG_HOME" "$XDG_DATA_HOME" "$XDG_STATE_HOME"
        mkdir -p "$XDG_CONFIG_HOME" "$XDG_DATA_HOME" "$XDG_STATE_HOME"

        cp -r /example/dotfiles-repo "$HOME/dotfiles-src"
        cp -r /example/module-repos "$HOME/module-repos"
        cd "$HOME/module-repos/nvim-config"
        git init -q -b main
        git -c user.email="$USER_EMAIL" -c user.name="Flow E2E" add -A
        git -c user.email="$USER_EMAIL" -c user.name="Flow E2E" commit -q -m initial

        cd "$HOME/dotfiles-src"
        git init -q -b main
        git -c user.email="$USER_EMAIL" -c user.name="Flow E2E" add -A
        git -c user.email="$USER_EMAIL" -c user.name="Flow E2E" commit -q -m initial
        cd "$HOME"
        """
    ).strip() + "\n" + "\n".join(commands) + "\n"


def _run_in_e2e_container(runtime: str, script: str) -> subprocess.CompletedProcess[str]:
    return subprocess.run(
        [
            runtime,
            "run",
            "--rm",
            "-v",
            f"{EXAMPLE_DIR}:/example:ro",
            IMAGE_TAG,
            "-c",
            script,
        ],
        capture_output=True,
        text=True,
    )


@pytest.fixture(scope="session")
def runtime() -> str:
    if os.environ.get("FLOW_RUN_E2E") != "1":
        pytest.skip("set FLOW_RUN_E2E=1 to run")

    selected_runtime = _pick_runtime()
    if selected_runtime is None:
        pytest.skip("neither podman nor docker is available")

    return selected_runtime


@pytest.fixture(scope="session")
def image(runtime: str):
    build = subprocess.run(
        [
            runtime, "build",
            "-f", str(CONTAINERFILE),
            "-t", IMAGE_TAG,
            str(REPO_ROOT),
        ],
        capture_output=True,
        text=True,
    )
    if build.returncode != 0:
        pytest.fail(f"image build failed:\n{build.stdout}\n{build.stderr}")

    try:
        yield IMAGE_TAG
    finally:
        subprocess.run(
            [runtime, "rmi", "-f", IMAGE_TAG],
            capture_output=True,
            text=True,
        )


@pytest.mark.skipif(
    os.environ.get("FLOW_RUN_E2E") != "1",
    reason="set FLOW_RUN_E2E=1 to run",
)
def test_dotfiles_init_and_link_in_container(runtime: str, image: str):
    result = _run_in_e2e_container(
        runtime,
        _flow_script(
            "flow dotfiles init --repo \"$HOME/dotfiles-src\"",
            "flow dotfiles link --profile linux-auto --skip _root",
            "test -L \"$HOME/.zshrc\"",
            "test -L \"$HOME/.gitconfig\"",
            "readlink \"$HOME/.zshrc\" | grep -q '/dotfiles/_shared/zsh/.zshrc'",
            "readlink \"$HOME/.gitconfig\" | grep -q '/dotfiles/_shared/git/.gitconfig'",
            "flow dotfiles link --profile linux-auto --skip _root",
            "flow dotfiles status",
        ),
    )
    assert result.returncode == 0, (
        f"e2e run failed (rc={result.returncode}):\n"
        f"stdout: {result.stdout}\n"
        f"stderr: {result.stderr}"
    )


@pytest.mark.skipif(
    os.environ.get("FLOW_RUN_E2E") != "1",
    reason="set FLOW_RUN_E2E=1 to run",
)
def test_cli_paths_run_in_disposable_container(runtime: str, image: str):
    result = _run_in_e2e_container(
        runtime,
        _flow_script(
            "flow --version | tee /tmp/version.txt",
            "grep -q \"flow\" /tmp/version.txt",
            "flow --help | tee /tmp/help.txt",
            "test -s /tmp/help.txt",
            "flow completion zsh | tee /tmp/completion.zsh",
            "test -s /tmp/completion.zsh",
            "flow dotfiles init --repo \"$HOME/dotfiles-src\"",
            "flow dotfiles link --profile linux-auto --skip _root",
            "flow dotfiles status",
            "flow packages list --all | tee /tmp/packages.txt",
            "test -s /tmp/packages.txt",
            "flow packages install --profile linux-auto --dry-run | tee /tmp/package-dry-run.txt",
            "test -s /tmp/package-dry-run.txt",
            "flow setup show linux-auto | tee /tmp/setup.txt",
            "test -s /tmp/setup.txt",
        ),
    )
    assert result.returncode == 0, (
        f"e2e run failed (rc={result.returncode}):\n"
        f"stdout: {result.stdout}\n"
        f"stderr: {result.stderr}"
    )