"""
Tests for the MCP config writer utility (write_mcp_config).
"""

import json
import os

import pytest

from config import MCPConfig, MCPServerConfig, write_mcp_config


# ---------------------------------------------------------------------------
# Fixtures
# ---------------------------------------------------------------------------


@pytest.fixture
def workspace(tmp_path):
    """Return a temporary workspace directory path."""
    return str(tmp_path)


@pytest.fixture
def sample_mcp_config():
    """Return an MCPConfig with one server entry."""
    return MCPConfig(
        servers={
            "my-tool": MCPServerConfig(
                command="npx",
                args=["-y", "@my/tool"],
                env={"API_KEY": "test123"},
            )
        }
    )


# ---------------------------------------------------------------------------
# Tests: write_mcp_config
# ---------------------------------------------------------------------------


class TestWriteMcpConfig:
    def test_skips_when_no_servers(self, workspace):
        """Empty servers dict should not create any file."""
        write_mcp_config(MCPConfig(), workspace, use_claude=True)
        assert not os.path.exists(os.path.join(workspace, ".mcp.json"))
        assert not os.path.exists(os.path.join(workspace, "opencode.json"))

    def test_writes_mcp_json_for_claude(self, workspace, sample_mcp_config):
        """Claude runtime should produce .mcp.json with 'mcpServers' key."""
        write_mcp_config(sample_mcp_config, workspace, use_claude=True)
        path = os.path.join(workspace, ".mcp.json")
        assert os.path.isfile(path)

        with open(path, encoding="utf-8") as f:
            data = json.load(f)

        assert "mcpServers" in data
        assert "my-tool" in data["mcpServers"]
        srv = data["mcpServers"]["my-tool"]
        assert srv["command"] == "npx"
        assert srv["args"] == ["-y", "@my/tool"]
        assert srv["env"] == {"API_KEY": "test123"}

    def test_writes_opencode_json_for_opencode(self, workspace, sample_mcp_config):
        """OpenCode runtime should produce opencode.json with 'mcp' key."""
        write_mcp_config(sample_mcp_config, workspace, use_claude=False)
        path = os.path.join(workspace, "opencode.json")
        assert os.path.isfile(path)

        with open(path, encoding="utf-8") as f:
            data = json.load(f)

        assert "mcp" in data
        assert "my-tool" in data["mcp"]

    def test_multiple_servers(self, workspace):
        """Multiple server entries should all appear in the output."""
        cfg = MCPConfig(
            servers={
                "server-a": MCPServerConfig(command="cmd-a", args=["--flag"]),
                "server-b": MCPServerConfig(command="cmd-b", env={"X": "1"}),
            }
        )
        write_mcp_config(cfg, workspace, use_claude=True)

        with open(os.path.join(workspace, ".mcp.json"), encoding="utf-8") as f:
            data = json.load(f)

        assert len(data["mcpServers"]) == 2
        assert "server-a" in data["mcpServers"]
        assert "server-b" in data["mcpServers"]

    def test_creates_parent_directories(self, tmp_path):
        """Should create intermediate directories if workspace doesn't exist."""
        nested = str(tmp_path / "deep" / "nested" / "workspace")
        cfg = MCPConfig(
            servers={"s": MCPServerConfig(command="echo")}
        )
        write_mcp_config(cfg, nested, use_claude=True)
        assert os.path.isfile(os.path.join(nested, ".mcp.json"))

    def test_produces_valid_json(self, workspace, sample_mcp_config):
        """Output file must be valid, parseable JSON."""
        write_mcp_config(sample_mcp_config, workspace, use_claude=True)
        path = os.path.join(workspace, ".mcp.json")
        with open(path, encoding="utf-8") as f:
            data = json.load(f)  # Would raise on invalid JSON
        assert isinstance(data, dict)

    def test_overwrites_existing_file(self, workspace):
        """Writing twice should overwrite the previous config."""
        cfg1 = MCPConfig(servers={"old": MCPServerConfig(command="old-cmd")})
        cfg2 = MCPConfig(servers={"new": MCPServerConfig(command="new-cmd")})

        write_mcp_config(cfg1, workspace, use_claude=True)
        write_mcp_config(cfg2, workspace, use_claude=True)

        with open(os.path.join(workspace, ".mcp.json"), encoding="utf-8") as f:
            data = json.load(f)

        assert "new" in data["mcpServers"]
        assert "old" not in data["mcpServers"]

    def test_tilde_expansion(self, monkeypatch, tmp_path):
        """Workspace path with ~ should be expanded."""
        monkeypatch.setenv("HOME", str(tmp_path))
        # Also handle Windows
        monkeypatch.setattr(os.path, "expanduser", lambda p: p.replace("~", str(tmp_path)))

        cfg = MCPConfig(servers={"s": MCPServerConfig(command="echo")})
        write_mcp_config(cfg, "~/my-workspace", use_claude=False)
        assert os.path.isfile(os.path.join(str(tmp_path), "my-workspace", "opencode.json"))