from __future__ import annotations

import base64
import importlib
import json
import os
from pathlib import Path
import sys
from typing import Any
from unittest.mock import AsyncMock, MagicMock, patch

import httpx
import pytest
import zstandard

from vibe.core.teleport.errors import (
    ServiceTeleportError,
    ServiceTeleportNotSupportedError,
)
from vibe.core.teleport.git import GitRepoInfo
from vibe.core.teleport.teleport import TeleportService
from vibe.core.teleport.types import (
    TeleportCheckingGitEvent,
    TeleportCompleteEvent,
    TeleportPushingEvent,
    TeleportPushRequiredEvent,
    TeleportPushResponseEvent,
    TeleportStartingWorkflowEvent,
)


def _reimport_agent_loop() -> Any:
    to_clear = ("vibe.core.agent_loop", "git", "vibe.core.teleport")
    for k in [k for k in sys.modules if any(k.startswith(m) for m in to_clear)]:
        del sys.modules[k]
    return importlib.import_module("vibe.core.agent_loop")


def _make_service(tmp_path: Path, **kwargs: Any) -> TeleportService:
    return TeleportService(
        session_logger=MagicMock(),
        vibe_code_sessions_base_url=kwargs.pop(
            "vibe_code_sessions_base_url", "https://api.example.com"
        ),
        vibe_code_api_key=kwargs.pop("vibe_code_api_key", "api-key"),
        workdir=tmp_path,
        **kwargs,
    )


def _mock_handler() -> Any:
    async def handler(request: httpx.Request) -> httpx.Response:
        return httpx.Response(
            200,
            json={
                "sessionId": "controller-session-id",
                "webSessionId": "web-session-id",
                "projectId": "project-id",
                "status": "running",
                "url": "https://chat.example.com/code/project-id/web-session-id",
            },
        )

    return handler


class TestTeleportServiceCompressDiff:
    @pytest.fixture
    def service(self, tmp_path: Path) -> TeleportService:
        return _make_service(tmp_path)

    def test_returns_none_for_empty_diff(self, service: TeleportService) -> None:
        assert service._compress_diff("") is None

    def test_compresses_and_encodes_diff(self, service: TeleportService) -> None:
        diff = "diff --git a/file.txt b/file.txt\n+new line"
        result = service._compress_diff(diff)

        assert result is not None
        decoded = base64.b64decode(result)
        decompressed = zstandard.ZstdDecompressor().decompress(decoded)
        assert decompressed.decode("utf-8") == diff

    def test_raises_when_diff_too_large(self, service: TeleportService) -> None:
        large_diff = "x" * 2_000_000
        with pytest.raises(ServiceTeleportError, match="Diff too large"):
            service._compress_diff(large_diff, max_size=100)


class TestTeleportServiceValidateConfig:
    def test_raises_when_no_api_key(self, tmp_path: Path) -> None:
        service = _make_service(tmp_path, vibe_code_api_key="")
        with pytest.raises(ServiceTeleportError, match="MISTRAL_API_KEY not set"):
            service._validate_config()

    def test_passes_when_api_key_set(self, tmp_path: Path) -> None:
        service = _make_service(tmp_path, vibe_code_api_key="valid-key")
        service._validate_config()

    def test_uses_custom_env_var_name_in_error(self, tmp_path: Path) -> None:
        mock_config = MagicMock()
        mock_config.vibe_code_api_key_env_var = "CUSTOM_API_KEY"
        service = _make_service(tmp_path, vibe_code_api_key="", vibe_config=mock_config)
        with pytest.raises(ServiceTeleportError, match="CUSTOM_API_KEY not set"):
            service._validate_config()


class TestTeleportServiceCheckSupported:
    @pytest.fixture
    def service(self, tmp_path: Path) -> TeleportService:
        return _make_service(tmp_path)

    @pytest.mark.asyncio
    async def test_check_supported_calls_git_info(
        self, service: TeleportService
    ) -> None:
        service._git.get_info = AsyncMock(
            return_value=GitRepoInfo(
                remote_url="https://github.com/owner/repo.git",
                owner="owner",
                repo="repo",
                branch="main",
                commit="abc123",
                diff="",
            )
        )
        await service.check_supported()
        service._git.get_info.assert_called_once()

    @pytest.mark.asyncio
    async def test_check_supported_raises_when_not_supported(
        self, service: TeleportService
    ) -> None:
        service._git.get_info = AsyncMock(
            side_effect=ServiceTeleportNotSupportedError(
                "Teleport requires a git repository."
            )
        )
        with pytest.raises(ServiceTeleportNotSupportedError):
            await service.check_supported()


class TestTeleportServiceIsSupported:
    @pytest.fixture
    def service(self, tmp_path: Path) -> TeleportService:
        return _make_service(tmp_path)

    @pytest.mark.asyncio
    async def test_is_supported_returns_true(self, service: TeleportService) -> None:
        service._git.is_supported = AsyncMock(return_value=True)
        assert await service.is_supported() is True

    @pytest.mark.asyncio
    async def test_is_supported_returns_false(self, service: TeleportService) -> None:
        service._git.is_supported = AsyncMock(return_value=False)
        assert await service.is_supported() is False


class TestTeleportServiceExecute:
    @pytest.mark.asyncio
    async def test_execute_happy_path(self, tmp_path: Path) -> None:
        seen_body: dict[str, object] | None = None
        seen_url: str | None = None

        async def handler(request: httpx.Request) -> httpx.Response:
            nonlocal seen_body, seen_url
            seen_url = str(request.url)
            seen_body = json.loads(request.content)
            return httpx.Response(
                200,
                json={
                    "sessionId": "controller-session-id",
                    "webSessionId": "web-session-id",
                    "projectId": "project-id",
                    "status": "running",
                    "url": "https://chat.example.com/code/project-id/web-session-id",
                },
            )

        async with httpx.AsyncClient(transport=httpx.MockTransport(handler)) as client:
            service = _make_service(
                tmp_path,
                vibe_code_sessions_base_url="https://chat.example.com",
                client=client,
            )
            service._git.fetch = AsyncMock()
            service._git.get_info = AsyncMock(
                return_value=GitRepoInfo(
                    remote_url="https://github.com/owner/repo",
                    owner="owner",
                    repo="repo",
                    branch="main",
                    commit="abc123",
                    diff="some local diff",
                )
            )
            service._git.is_commit_pushed = AsyncMock(return_value=True)
            service._git.is_branch_pushed = AsyncMock(return_value=True)

            events = [event async for event in service.execute("test prompt")]

        assert isinstance(events[0], TeleportCheckingGitEvent)
        assert isinstance(events[1], TeleportStartingWorkflowEvent)
        assert isinstance(events[2], TeleportCompleteEvent)
        assert (
            events[2].url == "https://chat.example.com/code/project-id/web-session-id"
        )
        assert seen_url == "https://chat.example.com/api/v1/code/sessions"
        assert seen_body is not None
        assert seen_body["message"] == {
            "role": "user",
            "parts": [{"type": "text", "text": "test prompt"}],
        }
        repos = seen_body["context"]["repositories"]
        assert len(repos) == 1
        assert repos[0]["repoUrl"] == "https://github.com/owner/repo"
        assert repos[0]["branch"] == "main"
        assert repos[0]["commitSha"] == "abc123"
        assert repos[0]["diff"]["format"] == "git-diff"
        assert repos[0]["diff"]["encoding"] == "base64"
        assert repos[0]["diff"]["compression"] == "zstd"
        assert len(repos[0]["diff"]["content"]) > 0
        assert "idempotencyKey" in seen_body

    @pytest.mark.asyncio
    async def test_execute_requires_branch(self, tmp_path: Path) -> None:
        service = _make_service(tmp_path)
        service._git.fetch = AsyncMock()
        service._git.get_info = AsyncMock(
            return_value=GitRepoInfo(
                remote_url="https://github.com/owner/repo",
                owner="owner",
                repo="repo",
                branch=None,
                commit="abc123",
                diff="",
            )
        )

        with pytest.raises(ServiceTeleportError, match="checked-out branch"):
            async for _ in service.execute("test prompt"):
                pass

        service._git.fetch.assert_not_awaited()

    @pytest.mark.asyncio
    async def test_execute_rejects_empty_prompt(self, tmp_path: Path) -> None:
        service = _make_service(tmp_path)
        with pytest.raises(ServiceTeleportError, match="non-empty prompt"):
            async for _ in service.execute(""):
                pass

    @pytest.mark.asyncio
    async def test_execute_push_confirmation_approved(self, tmp_path: Path) -> None:
        async with httpx.AsyncClient(
            transport=httpx.MockTransport(_mock_handler())
        ) as client:
            service = _make_service(tmp_path, client=client)
            service._git.fetch = AsyncMock()
            service._git.get_info = AsyncMock(
                return_value=GitRepoInfo(
                    remote_url="https://github.com/owner/repo",
                    owner="owner",
                    repo="repo",
                    branch="main",
                    commit="abc123",
                    diff="",
                )
            )
            service._git.is_commit_pushed = AsyncMock(return_value=False)
            service._git.is_branch_pushed = AsyncMock(return_value=False)
            service._git.get_unpushed_commit_count = AsyncMock(return_value=2)
            service._git.push_current_branch = AsyncMock(return_value=True)

            gen = service.execute("test prompt")
            assert isinstance(await gen.asend(None), TeleportCheckingGitEvent)
            push_event = await gen.asend(None)
            assert isinstance(push_event, TeleportPushRequiredEvent)
            assert push_event.unpushed_count == 2
            assert push_event.branch_not_pushed is True
            assert isinstance(
                await gen.asend(TeleportPushResponseEvent(approved=True)),
                TeleportPushingEvent,
            )
            events = [event async for event in gen]

        service._git.push_current_branch.assert_awaited_once()
        assert isinstance(events[0], TeleportStartingWorkflowEvent)
        assert isinstance(events[1], TeleportCompleteEvent)

    @pytest.mark.asyncio
    async def test_execute_push_confirmation_declined(self, tmp_path: Path) -> None:
        service = _make_service(tmp_path)
        service._git.fetch = AsyncMock()
        service._git.get_info = AsyncMock(
            return_value=GitRepoInfo(
                remote_url="https://github.com/owner/repo",
                owner="owner",
                repo="repo",
                branch="main",
                commit="abc123",
                diff="",
            )
        )
        service._git.is_commit_pushed = AsyncMock(return_value=False)
        service._git.is_branch_pushed = AsyncMock(return_value=True)
        service._git.get_unpushed_commit_count = AsyncMock(return_value=1)

        gen = service.execute("test prompt")
        await gen.asend(None)
        await gen.asend(None)

        with pytest.raises(ServiceTeleportError, match="Teleport cancelled"):
            await gen.asend(TeleportPushResponseEvent(approved=False))


class TestTeleportServiceContextManager:
    @pytest.mark.asyncio
    async def test_creates_client_on_enter(self, tmp_path: Path) -> None:
        service = _make_service(tmp_path)
        assert service._client is None
        async with service:
            assert service._client is not None
            assert service._nuage_client_instance is not None
        assert service._client is None


class TestTeleportAvailability:
    def test_teleport_available_is_false_when_git_not_installed(self) -> None:
        with patch.dict(os.environ, {"GIT_PYTHON_GIT_EXECUTABLE": "/nonexistent/git"}):
            agent_loop = _reimport_agent_loop()
            assert agent_loop._TELEPORT_AVAILABLE is False

    def test_teleport_service_raises_error_when_git_not_available(self) -> None:
        with patch.dict(os.environ, {"GIT_PYTHON_GIT_EXECUTABLE": "/nonexistent/git"}):
            agent_loop = _reimport_agent_loop()
            with pytest.raises(agent_loop.TeleportError, match="git to be installed"):
                agent_loop.AgentLoop.teleport_service.fget(
                    MagicMock(_teleport_service=None)
                )

    def test_teleport_available_is_true_when_git_installed(
        self, tmp_path: Path
    ) -> None:
        fake_git = tmp_path / "git"
        fake_git.write_text("#!/bin/sh\necho 'git version 2.0.0'")
        fake_git.chmod(0o755)
        with patch.dict(os.environ, {"GIT_PYTHON_GIT_EXECUTABLE": str(fake_git)}):
            agent_loop = _reimport_agent_loop()
            assert agent_loop._TELEPORT_AVAILABLE is True