package aicra

import (
	"fmt"
	"io"
	"os"

	"git.xdrm.io/go/aicra/datatype"
	"git.xdrm.io/go/aicra/dynamic"
	"git.xdrm.io/go/aicra/internal/config"
)

// Server represents an AICRA instance featuring: type checkers, services
type Server struct {
	config   *config.Server
	handlers []*handler
}

// New creates a framework instance from a configuration file
func New(configPath string, dtypes ...datatype.T) (*Server, error) {
	var (
		err        error
		configFile io.ReadCloser
	)

	// 1. init instance
	var i = &Server{
		config:   nil,
		handlers: make([]*handler, 0),
	}

	// 2. open config file
	configFile, err = os.Open(configPath)
	if err != nil {
		return nil, err
	}
	defer configFile.Close()

	// 3. load configuration
	i.config, err = config.Parse(configFile, dtypes...)
	if err != nil {
		return nil, err
	}

	return i, nil

}

// Handle sets a new handler for an HTTP method to a path
func (s *Server) Handle(method, path string, fn dynamic.HandlerFn) error {
	// find associated service
	var found *config.Service = nil
	for _, service := range s.config.Services {
		if method == service.Method && path == service.Pattern {
			found = service
			break
		}
	}
	if found == nil {
		return fmt.Errorf("%s '%s': %w", method, path, ErrNoServiceForHandler)
	}

	handler, err := createHandler(method, path, *found, fn)
	if err != nil {
		return err
	}
	s.handlers = append(s.handlers, handler)
	return nil
}

// ToHTTPServer converts the server to a http server
func (s Server) ToHTTPServer() (*httpServer, error) {

	// check if handlers are missing
	for _, service := range s.config.Services {
		found := false
		for _, handler := range s.handlers {
			if handler.Method == service.Method && handler.Path == service.Pattern {
				found = true
				break
			}
		}
		if !found {
			return nil, fmt.Errorf("%s '%s': %w", service.Method, service.Pattern, ErrNoHandlerForService)
		}
	}

	// 2. cast to http server
	httpServer := httpServer(s)
	return &httpServer, nil
}