package graph

import (
	"encoding/json"
	"testing"

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

	"gitlab.com/unboundsoftware/schemas/graph/model"
)

func TestGenerateCosmoRouterConfig(t *testing.T) {
	tests := []struct {
		name      string
		subGraphs []*model.SubGraph
		wantErr   bool
		validate  func(t *testing.T, config string)
	}{
		{
			name: "single subgraph with all fields",
			subGraphs: []*model.SubGraph{
				{
					Service: "test-service",
					URL:     stringPtr("http://localhost:4001/query"),
					WsURL:   stringPtr("ws://localhost:4001/query"),
					Sdl:     "type Query { test: String }",
				},
			},
			wantErr: false,
			validate: func(t *testing.T, config string) {
				var result map[string]interface{}
				err := json.Unmarshal([]byte(config), &result)
				require.NoError(t, err, "Config should be valid JSON")

				// Version is a UUID string from wgc
				version, ok := result["version"].(string)
				require.True(t, ok, "Version should be a string")
				assert.NotEmpty(t, version, "Version should not be empty")

				subgraphs, ok := result["subgraphs"].([]interface{})
				require.True(t, ok, "subgraphs should be an array")
				require.Len(t, subgraphs, 1, "Should have 1 subgraph")

				sg := subgraphs[0].(map[string]interface{})
				assert.Equal(t, "test-service", sg["name"])
				assert.Equal(t, "http://localhost:4001/query", sg["routingUrl"])

				// Check that datasource configurations include subscription settings
				engineConfig, ok := result["engineConfig"].(map[string]interface{})
				require.True(t, ok, "Should have engineConfig")

				dsConfigs, ok := engineConfig["datasourceConfigurations"].([]interface{})
				require.True(t, ok && len(dsConfigs) > 0, "Should have datasource configurations")

				ds := dsConfigs[0].(map[string]interface{})
				customGraphql, ok := ds["customGraphql"].(map[string]interface{})
				require.True(t, ok, "Should have customGraphql config")

				subscription, ok := customGraphql["subscription"].(map[string]interface{})
				require.True(t, ok, "Should have subscription config")
				assert.True(t, subscription["enabled"].(bool), "Subscription should be enabled")

				subUrl, ok := subscription["url"].(map[string]interface{})
				require.True(t, ok, "Should have subscription URL")
				assert.Equal(t, "ws://localhost:4001/query", subUrl["staticVariableContent"])
			},
		},
		{
			name: "multiple subgraphs",
			subGraphs: []*model.SubGraph{
				{
					Service: "service-1",
					URL:     stringPtr("http://localhost:4001/query"),
					Sdl:     "type Query { field1: String }",
				},
				{
					Service: "service-2",
					URL:     stringPtr("http://localhost:4002/query"),
					Sdl:     "type Query { field2: String }",
				},
				{
					Service: "service-3",
					URL:     stringPtr("http://localhost:4003/query"),
					WsURL:   stringPtr("ws://localhost:4003/query"),
					Sdl:     "type Subscription { updates: String }",
				},
			},
			wantErr: false,
			validate: func(t *testing.T, config string) {
				var result map[string]interface{}
				err := json.Unmarshal([]byte(config), &result)
				require.NoError(t, err)

				subgraphs := result["subgraphs"].([]interface{})
				assert.Len(t, subgraphs, 3, "Should have 3 subgraphs")

				// Check service names
				sg1 := subgraphs[0].(map[string]interface{})
				assert.Equal(t, "service-1", sg1["name"])

				sg3 := subgraphs[2].(map[string]interface{})
				assert.Equal(t, "service-3", sg3["name"])

				// Check that datasource configurations include subscription for service-3
				engineConfig, ok := result["engineConfig"].(map[string]interface{})
				require.True(t, ok, "Should have engineConfig")

				dsConfigs, ok := engineConfig["datasourceConfigurations"].([]interface{})
				require.True(t, ok && len(dsConfigs) == 3, "Should have 3 datasource configurations")

				// Find service-3's datasource config (should have subscription enabled)
				ds3 := dsConfigs[2].(map[string]interface{})
				customGraphql, ok := ds3["customGraphql"].(map[string]interface{})
				require.True(t, ok, "Service-3 should have customGraphql config")

				subscription, ok := customGraphql["subscription"].(map[string]interface{})
				require.True(t, ok, "Service-3 should have subscription config")
				assert.True(t, subscription["enabled"].(bool), "Service-3 subscription should be enabled")
			},
		},
		{
			name: "subgraph with no URL",
			subGraphs: []*model.SubGraph{
				{
					Service: "test-service",
					URL:     nil,
					WsURL:   nil,
					Sdl:     "type Query { test: String }",
				},
			},
			wantErr: false,
			validate: func(t *testing.T, config string) {
				var result map[string]interface{}
				err := json.Unmarshal([]byte(config), &result)
				require.NoError(t, err)

				subgraphs := result["subgraphs"].([]interface{})
				sg := subgraphs[0].(map[string]interface{})

				// Should not have routing URL when URL is nil
				_, hasRoutingURL := sg["routingUrl"]
				assert.False(t, hasRoutingURL, "Should not have routingUrl when URL is nil")

				// Check datasource configurations don't have subscription enabled
				engineConfig, ok := result["engineConfig"].(map[string]interface{})
				require.True(t, ok, "Should have engineConfig")

				dsConfigs, ok := engineConfig["datasourceConfigurations"].([]interface{})
				require.True(t, ok && len(dsConfigs) > 0, "Should have datasource configurations")

				ds := dsConfigs[0].(map[string]interface{})
				customGraphql, ok := ds["customGraphql"].(map[string]interface{})
				require.True(t, ok, "Should have customGraphql config")

				subscription, ok := customGraphql["subscription"].(map[string]interface{})
				if ok {
					// wgc always enables subscription but URL should be empty when WsURL is nil
					subUrl, hasUrl := subscription["url"].(map[string]interface{})
					if hasUrl {
						_, hasStaticContent := subUrl["staticVariableContent"]
						assert.False(t, hasStaticContent, "Subscription URL should be empty when WsURL is nil")
					}
				}
			},
		},
		{
			name:      "empty subgraphs",
			subGraphs: []*model.SubGraph{},
			wantErr:   true,
			validate:  nil,
		},
		{
			name:      "nil subgraphs",
			subGraphs: nil,
			wantErr:   true,
			validate:  nil,
		},
		{
			name: "complex SDL with multiple types",
			subGraphs: []*model.SubGraph{
				{
					Service: "complex-service",
					URL:     stringPtr("http://localhost:4001/query"),
					Sdl: `
						type Query {
							user(id: ID!): User
							users: [User!]!
						}

						type User {
							id: ID!
							name: String!
							email: String!
						}
					`,
				},
			},
			wantErr: false,
			validate: func(t *testing.T, config string) {
				var result map[string]interface{}
				err := json.Unmarshal([]byte(config), &result)
				require.NoError(t, err)

				// Check the composed graphqlSchema contains the types
				engineConfig, ok := result["engineConfig"].(map[string]interface{})
				require.True(t, ok, "Should have engineConfig")

				graphqlSchema, ok := engineConfig["graphqlSchema"].(string)
				require.True(t, ok, "Should have graphqlSchema")

				assert.Contains(t, graphqlSchema, "Query", "Schema should contain Query type")
				assert.Contains(t, graphqlSchema, "User", "Schema should contain User type")

				// Check datasource has the original SDL
				dsConfigs, ok := engineConfig["datasourceConfigurations"].([]interface{})
				require.True(t, ok && len(dsConfigs) > 0, "Should have datasource configurations")

				ds := dsConfigs[0].(map[string]interface{})
				customGraphql, ok := ds["customGraphql"].(map[string]interface{})
				require.True(t, ok, "Should have customGraphql config")

				federation, ok := customGraphql["federation"].(map[string]interface{})
				require.True(t, ok, "Should have federation config")

				serviceSdl, ok := federation["serviceSdl"].(string)
				require.True(t, ok, "Should have serviceSdl")
				assert.Contains(t, serviceSdl, "email: String!", "SDL should contain email field")
			},
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			config, err := GenerateCosmoRouterConfig(tt.subGraphs)

			if tt.wantErr {
				assert.Error(t, err)
				return
			}

			require.NoError(t, err)
			assert.NotEmpty(t, config, "Config should not be empty")

			if tt.validate != nil {
				tt.validate(t, config)
			}
		})
	}
}

// Helper function for tests
func stringPtr(s string) *string {
	return &s
}