aicra/server.go

102 lines
2.1 KiB
Go

package aicra
import (
"net/http"
"git.xdrm.io/go/aicra/api"
"git.xdrm.io/go/aicra/internal/config"
"git.xdrm.io/go/aicra/internal/reqdata"
)
// Server hides the builder and allows handling http requests
type Server Builder
// ServeHTTP implements http.Handler and is called on each request
func (server Server) ServeHTTP(res http.ResponseWriter, req *http.Request) {
defer req.Body.Close()
// 1. find a matching service in the config
service := server.conf.Find(req)
if service == nil {
errorHandler(api.ErrorUnknownService)
return
}
// 2. extract request data
dataset, err := extractRequestData(service, *req)
if err != nil {
errorHandler(api.ErrorMissingParam)
return
}
// 3. find a matching handler
var handler *apiHandler
for _, h := range server.handlers {
if h.Method == service.Method && h.Path == service.Pattern {
handler = h
}
}
// 4. fail if found no handler
if handler == nil {
errorHandler(api.ErrorUncallableService)
return
}
// 5. execute
returned, apiErr := handler.dyn.Handle(dataset.Data)
// 6. build response from returned data
response := api.EmptyResponse().WithError(apiErr)
for key, value := range returned {
// find original name from rename
for name, param := range service.Output {
if param.Rename == key {
response.SetData(name, value)
}
}
}
// 7. apply headers
res.Header().Set("Content-Type", "application/json; charset=utf-8")
for key, values := range response.Headers {
for _, value := range values {
res.Header().Add(key, value)
}
}
response.ServeHTTP(res, req)
}
func errorHandler(err api.Error) http.HandlerFunc {
return func(res http.ResponseWriter, req *http.Request) {
r := api.EmptyResponse().WithError(err)
r.ServeHTTP(res, req)
}
}
func extractRequestData(service *config.Service, req http.Request) (*reqdata.T, error) {
dataset := reqdata.New(service)
// 3. extract URI data
err := dataset.GetURI(req)
if err != nil {
return nil, err
}
// 4. extract query data
err = dataset.GetQuery(req)
if err != nil {
return nil, err
}
// 5. extract form/json data
err = dataset.GetForm(req)
if err != nil {
return nil, err
}
return dataset, nil
}