package gorillamux

import (
	"context"
	"net/http"
	"sort"
	"testing"

	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"

	"github.com/getkin/kin-openapi/openapi3"
	"github.com/getkin/kin-openapi/routers"
)

func TestRouter(t *testing.T) {
	helloCONNECT := &openapi3.Operation{Responses: openapi3.NewResponses()}
	helloDELETE := &openapi3.Operation{Responses: openapi3.NewResponses()}
	helloGET := &openapi3.Operation{Responses: openapi3.NewResponses()}
	helloHEAD := &openapi3.Operation{Responses: openapi3.NewResponses()}
	helloOPTIONS := &openapi3.Operation{Responses: openapi3.NewResponses()}
	helloPATCH := &openapi3.Operation{Responses: openapi3.NewResponses()}
	helloPOST := &openapi3.Operation{Responses: openapi3.NewResponses()}
	helloPUT := &openapi3.Operation{Responses: openapi3.NewResponses()}
	helloTRACE := &openapi3.Operation{Responses: openapi3.NewResponses()}
	paramsGET := &openapi3.Operation{Responses: openapi3.NewResponses()}
	booksPOST := &openapi3.Operation{Responses: openapi3.NewResponses()}
	partialGET := &openapi3.Operation{Responses: openapi3.NewResponses()}
	doc := &openapi3.T{
		OpenAPI: "3.0.0",
		Info: &openapi3.Info{
			Title:   "MyAPI",
			Version: "0.1",
		},
		Paths: openapi3.NewPaths(
			openapi3.WithPath("/hello", &openapi3.PathItem{
				Connect: helloCONNECT,
				Delete:  helloDELETE,
				Get:     helloGET,
				Head:    helloHEAD,
				Options: helloOPTIONS,
				Patch:   helloPATCH,
				Post:    helloPOST,
				Put:     helloPUT,
				Trace:   helloTRACE,
			}),
			openapi3.WithPath("/onlyGET", &openapi3.PathItem{
				Get: helloGET,
			}),
			openapi3.WithPath("/params/{x}/{y}/{z:.*}", &openapi3.PathItem{
				Get: paramsGET,
				Parameters: openapi3.Parameters{
					&openapi3.ParameterRef{Value: openapi3.NewPathParameter("x").WithSchema(openapi3.NewStringSchema())},
					&openapi3.ParameterRef{Value: openapi3.NewPathParameter("y").WithSchema(openapi3.NewFloat64Schema())},
					&openapi3.ParameterRef{Value: openapi3.NewPathParameter("z").WithSchema(openapi3.NewIntegerSchema())},
				},
			}),
			openapi3.WithPath("/books/{bookid}", &openapi3.PathItem{
				Get: paramsGET,
				Parameters: openapi3.Parameters{
					&openapi3.ParameterRef{Value: openapi3.NewPathParameter("bookid").WithSchema(openapi3.NewStringSchema())},
				},
			}),
			openapi3.WithPath("/books/{bookid}.json", &openapi3.PathItem{
				Post: booksPOST,
				Parameters: openapi3.Parameters{
					&openapi3.ParameterRef{Value: openapi3.NewPathParameter("bookid2").WithSchema(openapi3.NewStringSchema())},
				},
			}),
			openapi3.WithPath("/partial", &openapi3.PathItem{
				Get: partialGET,
			}),
		),
	}

	expect := func(r routers.Router, method string, uri string, operation *openapi3.Operation, params map[string]string) {
		t.Helper()
		req, err := http.NewRequest(method, uri, nil)
		require.NoError(t, err)
		route, pathParams, err := r.FindRoute(req)
		if err != nil {
			if operation == nil {
				pathItem := doc.Paths.Value(uri)
				if pathItem == nil {
					if err.Error() != routers.ErrPathNotFound.Error() {
						t.Fatalf("'%s %s': should have returned %q, but it returned an error: %v", method, uri, routers.ErrPathNotFound, err)
					}
					return
				}
				if pathItem.GetOperation(method) == nil {
					if err.Error() != routers.ErrMethodNotAllowed.Error() {
						t.Fatalf("'%s %s': should have returned %q, but it returned an error: %v", method, uri, routers.ErrMethodNotAllowed, err)
					}
				}
			} else {
				t.Fatalf("'%s %s': should have returned an operation, but it returned an error: %v", method, uri, err)
			}
		}
		if operation == nil && err == nil {
			t.Fatalf("'%s %s': should have failed, but returned\nroute = %+v\npathParams = %+v", method, uri, route, pathParams)
		}
		if route == nil {
			return
		}
		if route.Operation != operation {
			t.Fatalf("'%s %s': Returned wrong operation (%v)",
				method, uri, route.Operation)
		}
		if len(params) == 0 {
			if len(pathParams) != 0 {
				t.Fatalf("'%s %s': should return no path arguments, but found %+v", method, uri, pathParams)
			}
		} else {
			names := make([]string, 0, len(params))
			for name := range params {
				names = append(names, name)
			}
			sort.Strings(names)
			for _, name := range names {
				expected := params[name]
				actual, exists := pathParams[name]
				if !exists {
					t.Fatalf("'%s %s': path parameter %q should be %q, but it's not defined.", method, uri, name, expected)
				}
				if actual != expected {
					t.Fatalf("'%s %s': path parameter %q should be %q, but it's %q", method, uri, name, expected, actual)
				}
			}
		}
	}

	err := doc.Validate(context.Background())
	require.NoError(t, err)
	r, err := NewRouter(doc)
	require.NoError(t, err)

	expect(r, http.MethodGet, "/not_existing", nil, nil)
	expect(r, http.MethodDelete, "/hello", helloDELETE, nil)
	expect(r, http.MethodGet, "/hello", helloGET, nil)
	expect(r, http.MethodHead, "/hello", helloHEAD, nil)
	expect(r, http.MethodPatch, "/hello", helloPATCH, nil)
	expect(r, http.MethodPost, "/hello", helloPOST, nil)
	expect(r, http.MethodPut, "/hello", helloPUT, nil)
	expect(r, http.MethodGet, "/params/a/b/", paramsGET, map[string]string{
		"x": "a",
		"y": "b",
		"z": "",
	})
	expect(r, http.MethodGet, "/params/a/b/c%2Fd", paramsGET, map[string]string{
		"x": "a",
		"y": "b",
		"z": "c%2Fd",
	})
	expect(r, http.MethodGet, "/books/War.and.Peace", paramsGET, map[string]string{
		"bookid": "War.and.Peace",
	})
	expect(r, http.MethodPost, "/books/War.and.Peace.json", booksPOST, map[string]string{
		"bookid": "War.and.Peace",
	})
	expect(r, http.MethodPost, "/partial", nil, nil)

	doc.Servers = []*openapi3.Server{
		{URL: "https://www.example.com/api/v1"},
		{URL: "{scheme}://{d0}.{d1}.com/api/v1/", Variables: map[string]*openapi3.ServerVariable{
			"d0":     {Default: "www"},
			"d1":     {Default: "example", Enum: []string{"example"}},
			"scheme": {Default: "https", Enum: []string{"https", "http"}},
		}},
		{URL: "http://127.0.0.1:{port}/api/v1", Variables: map[string]*openapi3.ServerVariable{
			"port": {Default: "8000"},
		}},
	}
	err = doc.Validate(context.Background())
	require.NoError(t, err)
	r, err = NewRouter(doc)
	require.NoError(t, err)
	expect(r, http.MethodGet, "/hello", nil, nil)
	expect(r, http.MethodGet, "/api/v1/hello", nil, nil)
	expect(r, http.MethodGet, "www.example.com/api/v1/hello", nil, nil)
	expect(r, http.MethodGet, "https:///api/v1/hello", nil, nil)
	expect(r, http.MethodGet, "https://www.example.com/hello", nil, nil)
	expect(r, http.MethodGet, "https://www.example.com/api/v1/hello", helloGET, nil)
	expect(r, http.MethodGet, "https://domain0.domain1.com/api/v1/hello", helloGET, map[string]string{
		"d0": "domain0",
		"d1": "domain1",
		// "scheme": "https", TODO: https://github.com/gorilla/mux/issues/624
	})
	expect(r, http.MethodGet, "http://127.0.0.1:8000/api/v1/hello", helloGET, map[string]string{
		"port": "8000",
	})

	doc.Servers = []*openapi3.Server{
		{URL: "{server}", Variables: map[string]*openapi3.ServerVariable{
			"server": {Default: "/api/v1"},
		}},
	}
	err = doc.Validate(context.Background())
	require.NoError(t, err)
	r, err = NewRouter(doc)
	require.NoError(t, err)
	expect(r, http.MethodGet, "https://myserver/api/v1/hello", helloGET, nil)

	{
		uri := "https://www.example.com/api/v1/onlyGET"
		expect(r, http.MethodGet, uri, helloGET, nil)
		req, err := http.NewRequest(http.MethodDelete, uri, nil)
		require.NoError(t, err)
		require.NotNil(t, req)
		route, pathParams, err := r.FindRoute(req)
		require.EqualError(t, err, routers.ErrMethodNotAllowed.Error())
		require.Nil(t, route)
		require.Nil(t, pathParams)
	}
}

func TestPermuteScheme(t *testing.T) {
	scheme0 := "{sche}{me}"
	server := &openapi3.Server{URL: scheme0 + "://{d0}.{d1}.com/api/v1/", Variables: map[string]*openapi3.ServerVariable{
		"d0":   {Default: "www"},
		"d1":   {Default: "example", Enum: []string{"example"}},
		"sche": {Default: "http"},
		"me":   {Default: "s", Enum: []string{"", "s"}},
	}}
	err := server.Validate(context.Background())
	require.NoError(t, err)
	perms := permutePart(scheme0, server)
	require.Equal(t, []string{"http", "https"}, perms)
}

func TestServerPath(t *testing.T) {
	server := &openapi3.Server{URL: "http://example.com"}
	err := server.Validate(context.Background())
	require.NoError(t, err)

	_, err = NewRouter(&openapi3.T{Servers: openapi3.Servers{
		server,
		&openapi3.Server{URL: "http://example.com/"},
		&openapi3.Server{URL: "http://example.com/path"},
		newServerWithVariables(
			"{scheme}://localhost",
			map[string]string{
				"scheme": "https",
			}),
		newServerWithVariables(
			"{url}",
			map[string]string{
				"url": "http://example.com/path",
			}),
		newServerWithVariables(
			"http://example.com:{port}/path",
			map[string]string{
				"port": "8088",
			}),
		newServerWithVariables(
			"{server}",
			map[string]string{
				"server": "/",
			}),
		newServerWithVariables(
			"/",
			nil,
		),
	},
		Paths: openapi3.NewPaths(),
	})
	require.NoError(t, err)
}

func TestServerOverrideAtPathLevel(t *testing.T) {
	helloGET := &openapi3.Operation{Responses: openapi3.NewResponses()}
	doc := &openapi3.T{
		OpenAPI: "3.0.0",
		Info: &openapi3.Info{
			Title:   "rel",
			Version: "1",
		},
		Servers: openapi3.Servers{
			&openapi3.Server{
				URL: "https://example.com",
			},
		},
		Paths: openapi3.NewPaths(
			openapi3.WithPath("/hello", &openapi3.PathItem{
				Servers: openapi3.Servers{
					&openapi3.Server{
						URL: "https://another.com",
					},
				},
				Get: helloGET,
			}),
		),
	}
	err := doc.Validate(context.Background())
	require.NoError(t, err)
	router, err := NewRouter(doc)
	require.NoError(t, err)

	req, err := http.NewRequest(http.MethodGet, "https://another.com/hello", nil)
	require.NoError(t, err)
	route, _, err := router.FindRoute(req)
	require.Equal(t, "/hello", route.Path)

	req, err = http.NewRequest(http.MethodGet, "https://example.com/hello", nil)
	require.NoError(t, err)
	route, _, err = router.FindRoute(req)
	require.Nil(t, route)
	require.Error(t, err)
}

func TestRelativeURL(t *testing.T) {
	helloGET := &openapi3.Operation{Responses: openapi3.NewResponses()}
	doc := &openapi3.T{
		OpenAPI: "3.0.0",
		Info: &openapi3.Info{
			Title:   "rel",
			Version: "1",
		},
		Servers: openapi3.Servers{
			&openapi3.Server{
				URL: "/api/v1",
			},
		},
		Paths: openapi3.NewPaths(
			openapi3.WithPath("/hello", &openapi3.PathItem{
				Get: helloGET,
			}),
		),
	}
	err := doc.Validate(context.Background())
	require.NoError(t, err)
	router, err := NewRouter(doc)
	require.NoError(t, err)
	req, err := http.NewRequest(http.MethodGet, "https://example.com/api/v1/hello", nil)
	require.NoError(t, err)
	route, _, err := router.FindRoute(req)
	require.NoError(t, err)
	require.Equal(t, "/hello", route.Path)
}

func Test_makeServers(t *testing.T) {
	type testStruct struct {
		name    string
		servers openapi3.Servers
		want    []srv
		wantErr bool
		initFn  func(tt *testStruct)
	}
	tests := []testStruct{
		{
			name: "server is root path",
			servers: openapi3.Servers{
				newServerWithVariables("/", nil),
			},
			want: []srv{{
				schemes:     nil,
				host:        "",
				base:        "",
				server:      nil,
				varsUpdater: nil,
			}},
			wantErr: false,
			initFn: func(tt *testStruct) {
				for i, server := range tt.servers {
					tt.want[i].server = server
				}
			},
		},
		{
			name: "server with single variable that evaluates to root path",
			servers: openapi3.Servers{
				newServerWithVariables("{server}", map[string]string{"server": "/"}),
			},
			want: []srv{{
				schemes:     nil,
				host:        "",
				base:        "",
				server:      nil,
				varsUpdater: nil,
			}},
			wantErr: false,
			initFn: func(tt *testStruct) {
				for i, server := range tt.servers {
					tt.want[i].server = server
				}
			},
		},
		{
			name: "server is http://localhost:28002",
			servers: openapi3.Servers{
				newServerWithVariables("http://localhost:28002", nil),
			},
			want: []srv{{
				schemes:     []string{"http"},
				host:        "localhost:28002",
				base:        "",
				server:      nil,
				varsUpdater: nil,
			}},
			wantErr: false,
			initFn: func(tt *testStruct) {
				for i, server := range tt.servers {
					tt.want[i].server = server
				}
			},
		},
		{
			name: "server with single variable that evaluates to http://localhost:28002",
			servers: openapi3.Servers{
				newServerWithVariables("{server}", map[string]string{"server": "http://localhost:28002"}),
			},
			want: []srv{{
				schemes:     []string{"http"},
				host:        "localhost:28002",
				base:        "",
				server:      nil,
				varsUpdater: nil,
			}},
			wantErr: false,
			initFn: func(tt *testStruct) {
				for i, server := range tt.servers {
					tt.want[i].server = server
				}
			},
		},
		{
			name: "server with multiple variables that evaluates to http://localhost:28002",
			servers: openapi3.Servers{
				newServerWithVariables("{scheme}://{host}:{port}", map[string]string{"scheme": "http", "host": "localhost", "port": "28002"}),
			},
			want: []srv{{
				schemes:     []string{"http"},
				host:        "{host}:28002",
				base:        "",
				server:      nil,
				varsUpdater: func(vars map[string]string) { vars["port"] = "28002" },
			}},
			wantErr: false,
			initFn: func(tt *testStruct) {
				for i, server := range tt.servers {
					tt.want[i].server = server
				}
			},
		},
		{
			name: "server with unparsable URL fails",
			servers: openapi3.Servers{
				newServerWithVariables("exam^ple.com:443", nil),
			},
			want:    nil,
			wantErr: true,
			initFn:  nil,
		},
		{
			name: "server with single variable that evaluates to unparsable URL fails",
			servers: openapi3.Servers{
				newServerWithVariables("{server}", map[string]string{"server": "exam^ple.com:443"}),
			},
			want:    nil,
			wantErr: true,
			initFn:  nil,
		},
	}
	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			if tt.initFn != nil {
				tt.initFn(&tt)
			}
			got, err := makeServers(tt.servers)
			if (err != nil) != tt.wantErr {
				t.Errorf("makeServers() error = %v, wantErr %v", err, tt.wantErr)
				return
			}
			assert.Equal(t, len(tt.want), len(got), "expected and actual servers lengths are not equal")
			for i := 0; i < len(tt.want); i++ {
				// Unfortunately using assert.Equals or reflect.DeepEquals isn't
				// an option because function pointers cannot be compared
				assert.Equal(t, tt.want[i].schemes, got[i].schemes)
				assert.Equal(t, tt.want[i].host, got[i].host)
				assert.Equal(t, tt.want[i].host, got[i].host)
				assert.Equal(t, tt.want[i].server, got[i].server)
				if tt.want[i].varsUpdater == nil {
					assert.Nil(t, got[i].varsUpdater, "expected and actual varsUpdater should point to same function")
				} else {
					assert.NotNil(t, got[i].varsUpdater, "expected and actual varsUpdater should point to same function")
				}
			}
		})
	}
}

func newServerWithVariables(url string, variables map[string]string) *openapi3.Server {
	var serverVariables = map[string]*openapi3.ServerVariable{}

	for key, value := range variables {
		serverVariables[key] = newServerVariable(value)
	}

	return &openapi3.Server{
		URL:         url,
		Description: "",
		Variables:   serverVariables,
	}
}

func newServerVariable(defaultValue string) *openapi3.ServerVariable {
	return &openapi3.ServerVariable{
		Enum:        nil,
		Default:     defaultValue,
		Description: "",
	}
}