import json
from urllib.parse import quote

import pytest
from mcp.server.session import ServerSessionT
from mcp.shared.context import LifespanContextT
from pydantic import BaseModel

from fastmcp import Context
from fastmcp.resources import FunctionResource, ResourceTemplate
from fastmcp.resources.template import match_uri_template


class TestResourceTemplate:
    """Test ResourceTemplate functionality."""

    def test_template_creation(self):
        """Test creating a template from a function."""

        def my_func(key: str, value: int) -> dict:
            return {"key": key, "value": value}

        template = ResourceTemplate.from_function(
            fn=my_func,
            uri_template="test://{key}/{value}",
            name="test",
        )
        assert template.uri_template == "test://{key}/{value}"
        assert template.name == "test"
        assert template.mime_type == "text/plain"  # default
        test_input = {"key": "test", "value": 42}
        assert template.fn(**test_input) == my_func(**test_input)

    def test_template_matches(self):
        """Test matching URIs against a template."""

        def my_func(key: str, value: int) -> dict:
            return {"key": key, "value": value}

        template = ResourceTemplate.from_function(
            fn=my_func,
            uri_template="test://{key}/{value}",
            name="test",
        )

        # Valid match
        params = template.matches("test://foo/123")
        assert params == {"key": "foo", "value": "123"}

        # No match
        assert template.matches("test://foo") is None
        assert template.matches("other://foo/123") is None

    def test_template_matches_with_prefix(self):
        """Test matching URIs against a template with a prefix."""

        def my_func(key: str, value: int) -> dict:
            return {"key": key, "value": value}

        template = ResourceTemplate.from_function(
            fn=my_func,
            uri_template="app+test://{key}/{value}",
            name="test",
        )

        # Valid match
        params = template.matches("app+test://foo/123")
        assert params == {"key": "foo", "value": "123"}

        # No match
        assert template.matches("test://foo/123") is None
        assert template.matches("test://foo") is None
        assert template.matches("other://foo/123") is None

    def test_template_uri_validation(self):
        """Test validation rule: URI template must have at least one parameter."""

        def my_func() -> dict:
            return {"data": "value"}

        with pytest.raises(
            ValueError, match="URI template must contain at least one parameter"
        ):
            ResourceTemplate.from_function(
                fn=my_func,
                uri_template="test://no-params",
                name="test",
            )

    def test_template_uri_params_subset_of_function_params(self):
        """Test validation rule: URI parameters must be a subset of function parameters."""

        def my_func(key: str, value: int) -> dict:
            return {"key": key, "value": value}

        # This should work - URI params are a subset of function params
        template = ResourceTemplate.from_function(
            fn=my_func,
            uri_template="test://{key}/{value}",
            name="test",
        )
        assert template.uri_template == "test://{key}/{value}"

        # This should fail - 'unknown' is not a function parameter
        with pytest.raises(
            ValueError,
            match="Required function arguments .* must be a subset of the URI parameters",
        ):
            ResourceTemplate.from_function(
                fn=my_func,
                uri_template="test://{key}/{unknown}",
                name="test",
            )

    def test_required_params_subset_of_uri_params(self):
        """Test validation rule: Required function parameters must be in URI parameters."""

        # Function with required parameters
        def func_with_required(
            required_param: str, optional_param: str = "default"
        ) -> dict:
            return {"required": required_param, "optional": optional_param}

        # This should work - required param is in URI
        template = ResourceTemplate.from_function(
            fn=func_with_required,
            uri_template="test://{required_param}",
            name="test",
        )
        assert template.uri_template == "test://{required_param}"

        # This should fail - required param is not in URI
        with pytest.raises(
            ValueError,
            match="Required function arguments .* must be a subset of the URI parameters",
        ):
            ResourceTemplate.from_function(
                fn=func_with_required,
                uri_template="test://{optional_param}",
                name="test",
            )

    def test_multiple_required_params(self):
        """Test validation with multiple required parameters."""

        def multi_required(param1: str, param2: int, optional: str = "default") -> dict:
            return {"p1": param1, "p2": param2, "opt": optional}

        # This works - all required params in URI
        template = ResourceTemplate.from_function(
            fn=multi_required,
            uri_template="test://{param1}/{param2}",
            name="test",
        )
        assert template.uri_template == "test://{param1}/{param2}"

        # This fails - missing one required param
        with pytest.raises(
            ValueError,
            match="Required function arguments .* must be a subset of the URI parameters",
        ):
            ResourceTemplate.from_function(
                fn=multi_required,
                uri_template="test://{param1}",
                name="test",
            )

    async def test_create_resource(self):
        """Test creating a resource from a template."""

        def my_func(key: str, value: int) -> dict:
            return {"key": key, "value": value}

        template = ResourceTemplate.from_function(
            fn=my_func,
            uri_template="test://{key}/{value}",
            name="test",
        )

        resource = await template.create_resource(
            "test://foo/123",
            {"key": "foo", "value": 123},
        )

        assert isinstance(resource, FunctionResource)
        content = await resource.read()
        assert isinstance(content, str)
        data = json.loads(content)
        assert data == {"key": "foo", "value": 123}

    async def test_template_error(self):
        """Test error handling in template resource creation."""

        def failing_func(x: str) -> str:
            raise ValueError("Test error")

        template = ResourceTemplate.from_function(
            fn=failing_func,
            uri_template="fail://{x}",
            name="fail",
        )

        with pytest.raises(ValueError, match="Error creating resource from template"):
            await template.create_resource("fail://test", {"x": "test"})

    async def test_async_text_resource(self):
        """Test creating a text resource from async function."""

        async def greet(name: str) -> str:
            return f"Hello, {name}!"

        template = ResourceTemplate.from_function(
            fn=greet,
            uri_template="greet://{name}",
            name="greeter",
        )

        resource = await template.create_resource(
            "greet://world",
            {"name": "world"},
        )

        assert isinstance(resource, FunctionResource)
        content = await resource.read()
        assert content == "Hello, world!"

    async def test_async_binary_resource(self):
        """Test creating a binary resource from async function."""

        async def get_bytes(value: str) -> bytes:
            return value.encode()

        template = ResourceTemplate.from_function(
            fn=get_bytes,
            uri_template="bytes://{value}",
            name="bytes",
        )

        resource = await template.create_resource(
            "bytes://test",
            {"value": "test"},
        )

        assert isinstance(resource, FunctionResource)
        content = await resource.read()
        assert content == b"test"

    async def test_basemodel_conversion(self):
        """Test handling of BaseModel types."""

        class MyModel(BaseModel):
            key: str
            value: int

        def get_data(key: str, value: int) -> MyModel:
            return MyModel(key=key, value=value)

        template = ResourceTemplate.from_function(
            fn=get_data,
            uri_template="test://{key}/{value}",
            name="test",
        )

        resource = await template.create_resource(
            "test://foo/123",
            {"key": "foo", "value": 123},
        )

        assert isinstance(resource, FunctionResource)
        content = await resource.read()
        assert isinstance(content, str)
        data = json.loads(content)
        assert data == {"key": "foo", "value": 123}

    async def test_custom_type_conversion(self):
        """Test handling of custom types."""

        class CustomData:
            def __init__(self, value: str):
                self.value = value

            def __str__(self) -> str:
                return self.value

        def get_data(value: str) -> CustomData:
            return CustomData(value)

        template = ResourceTemplate.from_function(
            fn=get_data,
            uri_template="test://{value}",
            name="test",
        )

        resource = await template.create_resource(
            "test://hello",
            {"value": "hello"},
        )

        assert isinstance(resource, FunctionResource)
        content = await resource.read()
        assert content == '"hello"'

    async def test_wildcard_param_can_create_resource(self):
        """Test that wildcard parameters are valid."""

        def identity(path: str) -> str:
            return path

        template = ResourceTemplate.from_function(
            fn=identity,
            uri_template="test://{path*}.py",
            name="test",
        )

        assert await template.create_resource(
            "test://path/to/test.py",
            {"path": "path/to/test.py"},
        )

    async def test_wildcard_param_matches(self):
        def identify(path: str) -> str:
            return path

        template = ResourceTemplate.from_function(
            fn=identify,
            uri_template="test://src/{path*}.py",
            name="test",
        )
        # Valid match
        params = template.matches("test://src/path/to/test.py")
        assert params == {"path": "path/to/test"}

    async def test_multiple_wildcard_params(self):
        """Test that multiple wildcard parameters are valid."""

        def identity(path: str, path2: str) -> str:
            return f"{path}/{path2}"

        template = ResourceTemplate.from_function(
            fn=identity,
            uri_template="test://{path*}/xyz/{path2*}",
            name="test",
        )

        params = template.matches("test://path/to/xyz/abc")
        assert params == {"path": "path/to", "path2": "abc"}

    async def test_wildcard_param_with_regular_param(self):
        """Test that a wildcard parameter can be used with a regular parameter."""

        def identity(prefix: str, path: str) -> str:
            return f"{prefix}/{path}"

        template = ResourceTemplate.from_function(
            fn=identity,
            uri_template="test://{prefix}/{path*}",
            name="test",
        )

        params = template.matches("test://src/path/to/test.py")
        assert params == {"prefix": "src", "path": "path/to/test.py"}

    async def test_function_with_varargs_not_allowed(self):
        def func(x: int, *args: int) -> int:
            return x + sum(args)

        with pytest.raises(
            ValueError,
            match=r"Functions with \*args are not supported as resource templates",
        ):
            ResourceTemplate.from_function(
                fn=func,
                uri_template="test://{x}/{args*}",
                name="test",
            )

    async def test_function_with_varkwargs_ok(self):
        def func(x: int, **kwargs: int) -> int:
            return x + sum(kwargs.values())

        template = ResourceTemplate.from_function(
            fn=func,
            uri_template="test://{x}/{y}/{z}",
            name="test",
        )
        assert template.uri_template == "test://{x}/{y}/{z}"


class TestMatchUriTemplate:
    """Test match_uri_template function."""

    @pytest.mark.parametrize(
        "uri, expected_params",
        [
            ("test://a/b", None),
            ("test://a/b/c", None),
            ("test://a/x/b", {"x": "x"}),
            ("test://a/x/y/b", None),
        ],
    )
    def test_match_uri_template_single_param(
        self, uri: str, expected_params: dict[str, str]
    ):
        """Test that match_uri_template uses the slash delimiter."""
        uri_template = "test://a/{x}/b"
        result = match_uri_template(uri=uri, uri_template=uri_template)
        assert result == expected_params

    @pytest.mark.parametrize(
        "uri, expected_params",
        [
            ("test://foo/123", {"x": "foo", "y": "123"}),
            ("test://bar/456", {"x": "bar", "y": "456"}),
            ("test://foo/bar", {"x": "foo", "y": "bar"}),
            ("test://foo/bar/baz", None),
            ("test://foo/email@domain.com", {"x": "foo", "y": "email@domain.com"}),
            ("test://two words/foo", {"x": "two words", "y": "foo"}),
            ("test://two.words/foo+bar", {"x": "two.words", "y": "foo+bar"}),
            (
                f"test://escaped{quote('/', safe='')}word/bar",
                {"x": "escaped/word", "y": "bar"},
            ),
            (
                f"test://escaped{quote('{', safe='')}x{quote('}', safe='')}word/bar",
                {"x": "escaped{x}word", "y": "bar"},
            ),
            ("prefix+test://foo/123", None),
            ("test://foo", None),
            ("other://foo/123", None),
            ("t.est://foo/bar", None),
        ],
    )
    def test_match_uri_template_simple_params(
        self, uri: str, expected_params: dict[str, str] | None
    ):
        """Test matching URIs against a template with simple parameters."""
        uri_template = "test://{x}/{y}"
        result = match_uri_template(uri=uri, uri_template=uri_template)
        assert result == expected_params

    @pytest.mark.parametrize(
        "uri, expected_params",
        [
            ("test://a/b/foo/c/d/123", {"x": "foo", "y": "123"}),
            ("test://a/b/bar/c/d/456", {"x": "bar", "y": "456"}),
            ("prefix+test://a/b/foo/c/d/123", None),
            ("test://a/b/foo", None),
            ("other://a/b/foo/c/d/123", None),
        ],
    )
    def test_match_uri_template_params_and_literal_segments(
        self, uri: str, expected_params: dict[str, str] | None
    ):
        """Test matching URIs against a template with parameters and literal segments."""
        uri_template = "test://a/b/{x}/c/d/{y}"
        result = match_uri_template(uri=uri, uri_template=uri_template)
        assert result == expected_params

    @pytest.mark.parametrize(
        "uri, expected_params",
        [
            ("prefix+test://foo/test/123", {"x": "foo", "y": "123"}),
            ("prefix+test://bar/test/456", {"x": "bar", "y": "456"}),
            ("test://foo/test/123", None),
            ("other.prefix+test://foo/test/123", None),
            ("other+prefix+test://foo/test/123", None),
        ],
    )
    def test_match_uri_template_with_prefix(
        self, uri: str, expected_params: dict[str, str] | None
    ):
        """Test matching URIs against a template with a prefix."""
        uri_template = "prefix+test://{x}/test/{y}"
        result = match_uri_template(uri=uri, uri_template=uri_template)
        assert result == expected_params

    def test_match_uri_template_quoted_params(self):
        uri_template = "user://{name}/{email}"
        quoted_name = quote("John Doe", safe="")
        quoted_email = quote("john@example.com", safe="")
        uri = f"user://{quoted_name}/{quoted_email}"
        result = match_uri_template(uri=uri, uri_template=uri_template)
        assert result == {"name": "John Doe", "email": "john@example.com"}

    @pytest.mark.parametrize(
        "uri, expected_params",
        [
            ("test://a/b", None),
            ("test://a/b/c", None),
            ("test://a/x/b", {"x": "x"}),
            ("test://a/x/y/b", {"x": "x/y"}),
            ("bad-prefix://a/x/y/b", None),
            ("test://a/x/y/z", None),
        ],
    )
    def test_match_uri_template_wildcard_param(
        self, uri: str, expected_params: dict[str, str]
    ):
        """Test that match_uri_template uses the slash delimiter."""
        uri_template = "test://a/{x*}/b"
        result = match_uri_template(uri=uri, uri_template=uri_template)
        assert result == expected_params

    @pytest.mark.parametrize(
        "uri, expected_params",
        [
            ("test://a/x/y/b/c/d", {"x": "x/y", "y": "c/d"}),
            ("bad-prefix://a/x/y/b/c/d", None),
            ("test://a/x/y/c/d", None),
            ("test://a/x/b/y", {"x": "x", "y": "y"}),
        ],
    )
    def test_match_uri_template_multiple_wildcard_params(
        self, uri: str, expected_params: dict[str, str]
    ):
        """Test that match_uri_template uses the slash delimiter."""
        uri_template = "test://a/{x*}/b/{y*}"
        result = match_uri_template(uri=uri, uri_template=uri_template)
        assert result == expected_params

    def test_match_uri_template_wildcard_and_literal_param(self):
        """Test that match_uri_template uses the slash delimiter."""
        uri = "test://a/x/y/b"
        uri_template = "test://a/{x*}/{y}"
        result = match_uri_template(uri=uri, uri_template=uri_template)
        assert result == {"x": "x/y", "y": "b"}

    def test_match_consecutive_params(self):
        """Test that consecutive parameters without a / are not matched."""
        uri = "test://a/x/y"
        uri_template = "test://a/{x}{y}"
        result = match_uri_template(uri=uri, uri_template=uri_template)
        assert result is None

    @pytest.mark.parametrize(
        "uri, expected_params",
        [
            ("file://abc/xyz.py", {"path": "xyz"}),
            ("file://abc/x/y/z.py", {"path": "x/y/z"}),
            ("file://abc/x/y/z/.py", {"path": "x/y/z/"}),
            ("file://abc/x/y/z.md", None),
            ("file://x/y/z.txt", None),
        ],
    )
    def test_match_uri_template_with_non_slash_suffix(
        self, uri: str, expected_params: dict[str, str]
    ):
        uri_template = "file://abc/{path*}.py"
        result = match_uri_template(uri=uri, uri_template=uri_template)
        assert result == expected_params


class TestContextHandling:
    """Test context handling in resource templates."""

    def test_context_parameter_detection(self):
        """Test that context parameters are properly detected in
        ResourceTemplate.from_function()."""

        def template_with_context(x: int, ctx: Context) -> str:
            return str(x)

        template = ResourceTemplate.from_function(
            fn=template_with_context,
            uri_template="test://{x}",
            name="test",
        )
        assert template.context_kwarg == "ctx"

        def template_without_context(x: int) -> str:
            return str(x)

        template = ResourceTemplate.from_function(
            fn=template_without_context,
            uri_template="test://{x}",
            name="test",
        )
        assert template.context_kwarg is None

    def test_parameterized_context_parameter_detection(self):
        """Test that parameterized context parameters are properly detected in
        ResourceTemplate.from_function()."""

        def template_with_context(
            x: int, ctx: Context[ServerSessionT, LifespanContextT]
        ) -> str:
            return str(x)

        template = ResourceTemplate.from_function(
            fn=template_with_context,
            uri_template="test://{x}",
            name="test",
        )
        assert template.context_kwarg == "ctx"

    def test_parameterized_union_context_parameter_detection(self):
        """Test that context parameters in a union are properly detected in
        ResourceTemplate.from_function()."""

        def template_with_context(
            x: int, ctx: Context[ServerSessionT, LifespanContextT] | None
        ) -> str:
            return str(x)

        template = ResourceTemplate.from_function(
            fn=template_with_context,
            uri_template="test://{x}",
            name="test",
        )
        assert template.context_kwarg == "ctx"

    async def test_context_injection(self):
        """Test that context is properly injected during resource creation."""

        def resource_with_context(x: int, ctx: Context) -> str:
            assert isinstance(ctx, Context)
            return str(x)

        template = ResourceTemplate.from_function(
            fn=resource_with_context,
            uri_template="test://{x}",
            name="test",
        )
        assert template.context_kwarg == "ctx"

        from fastmcp import FastMCP

        mcp = FastMCP()
        ctx = mcp.get_context()

        resource = await template.create_resource(
            "test://42",
            {"x": 42},
            context=ctx,
        )
        assert isinstance(resource, FunctionResource)
        content = await resource.read()
        assert content == "42"

    async def test_context_optional(self):
        """Test that context is optional when creating resources."""

        def resource_with_context(x: int, ctx: Context | None = None) -> str:
            return str(x)

        template = ResourceTemplate.from_function(
            fn=resource_with_context,
            uri_template="test://{x}",
            name="test",
        )
        assert template.context_kwarg == "ctx"

        # Should not raise an error when context is not provided
        resource = await template.create_resource(
            "test://42",
            {"x": 42},
        )
        assert isinstance(resource, FunctionResource)
        content = await resource.read()
        assert content == "42"
