package main

import (
	"encoding/json"
	"fmt"
	"log"
	"net/http"
	"io/ioutil"
    "gopkg.in/yaml.v3"
)

type ApiConfig struct {
	Version   string     `yaml:"version"`
	Project   string     `yaml:"project"`
	Endpoints []Endpoint `yaml:"endpoints"`
}

type Endpoint struct {
	Path             string     `yaml:"path"`
	Method           string     `yaml:"method"`
	CobolSource      string     `yaml:"cobol_source"`
	Procedure        string     `yaml:"procedure"`
	Arguments        []Argument `yaml:"arguments"`
	ResponseCopybook string     `yaml:"response_copybook"`
}

type Argument struct {
	Name   string `yaml:"name"`
	Target string `yaml:"target"`
	Type   string `yaml:"type"`
	Source string `yaml:"source"`
}

func readConf(filename string) (*ApiConfig, error) {
    buf, err := ioutil.ReadFile(filename)
    if err != nil {
        return nil, err
    }

    c := &ApiConfig{}
    err = yaml.Unmarshal(buf, c)
    if err != nil {
        return nil, fmt.Errorf("in file %q: %w", filename, err)
    }

    return c, err
}

func projectHandler(w http.ResponseWriter, r *http.Request) {
	if r.Method != http.MethodGet {
		http.Error(w, "Method not allowed", http.StatusMethodNotAllowed)
		return
	}

	w.Header().Set("Content-Type", "application/json")

	api, err := readConf("api.yaml")
    if err != nil {
        log.Fatal(err)
    }
	
	response := map[string]string{"project": api.Project}
	json.NewEncoder(w).Encode(response)
}

func main() {
	http.HandleFunc("/project", projectHandler)

	port := ":8080"
	fmt.Printf("Server starting on port %s...\n", port)
	if err := http.ListenAndServe(port, nil); err != nil {
		log.Fatalf("Server failed to start: %v", err)
	}
}