package handlers

import "encoding/json"
import "net/http"

import "codit/internal/db"
import "github.com/graphql-go/graphql"

type GraphQL struct {
	Schema graphql.Schema
	Store  *db.Store
}

type graphQLRequest struct {
	Query     string                 `json:"query"`
	Variables map[string]interface{} `json:"variables"`
}

func NewGraphQL(store *db.Store) (*GraphQL, error) {
	var userType *graphql.Object
	userType = graphql.NewObject(graphql.ObjectConfig{
		Name: "User",
		Fields: graphql.Fields{
			"id": &graphql.Field{Type: graphql.String},
			"username": &graphql.Field{Type: graphql.String},
			"display_name": &graphql.Field{Type: graphql.String},
			"email": &graphql.Field{Type: graphql.String},
			"is_admin": &graphql.Field{Type: graphql.Boolean},
		},
	})

	var projectType *graphql.Object
	projectType = graphql.NewObject(graphql.ObjectConfig{
		Name: "Project",
		Fields: graphql.Fields{
			"id": &graphql.Field{Type: graphql.String},
			"slug": &graphql.Field{Type: graphql.String},
			"name": &graphql.Field{Type: graphql.String},
			"description": &graphql.Field{Type: graphql.String},
		},
	})

	var repoType *graphql.Object
	repoType = graphql.NewObject(graphql.ObjectConfig{
		Name: "Repo",
		Fields: graphql.Fields{
			"id": &graphql.Field{Type: graphql.String},
			"project_id": &graphql.Field{Type: graphql.String},
			"name": &graphql.Field{Type: graphql.String},
		},
	})

	var rootQuery *graphql.Object
	rootQuery = graphql.NewObject(graphql.ObjectConfig{
		Name: "Query",
		Fields: graphql.Fields{
			"users": &graphql.Field{
				Type: graphql.NewList(userType),
				Resolve: func(p graphql.ResolveParams) (interface{}, error) {
					return store.ListUsers()
				},
			},
			"projects": &graphql.Field{
				Type: graphql.NewList(projectType),
				Resolve: func(p graphql.ResolveParams) (interface{}, error) {
					return store.ListProjects()
				},
			},
			"repos": &graphql.Field{
				Type: graphql.NewList(repoType),
				Args: graphql.FieldConfigArgument{
					"project_id": &graphql.ArgumentConfig{Type: graphql.NewNonNull(graphql.String)},
				},
				Resolve: func(p graphql.ResolveParams) (interface{}, error) {
					var projectID string
					var ok bool
					projectID, ok = p.Args["project_id"].(string)
					if !ok {
						return store.ListRepos("")
					}
					return store.ListRepos(projectID)
				},
			},
		},
	})

	var schema graphql.Schema
	var err error
	schema, err = graphql.NewSchema(graphql.SchemaConfig{Query: rootQuery})
	if err != nil {
		return nil, err
	}

	return &GraphQL{Schema: schema, Store: store}, nil
}

func (g *GraphQL) ServeHTTP(w http.ResponseWriter, r *http.Request) {
	var req graphQLRequest
	var err error
	err = json.NewDecoder(r.Body).Decode(&req)
	if err != nil {
		WriteJSON(w, http.StatusBadRequest, map[string]string{"error": "invalid json"})
		return
	}
	var result *graphql.Result
	result = graphql.Do(graphql.Params{Schema: g.Schema, RequestString: req.Query, VariableValues: req.Variables})
	WriteJSON(w, http.StatusOK, result)
}