package main

import (
	"encoding/json"
	"io/ioutil"
	"log"
	"net/http"
	"strings"

	"github.com/woodpecker-ci/woodpecker/server/model"
	"gopkg.in/yaml.v3"
)

type config struct {
	Name string `json:"name"`
	Data string `json:"data"`
}

type incoming struct {
	Repo          *model.Repo  `json:"repo"`
	Build         *model.Build `json:"build"`
	Configuration []*config    `json:"configs"`
}

type pipeline struct {
	Extend string `yaml:"extend"`
}

func main() {
	log.Println("Woodpecker central config server")

	http.HandleFunc("/ciconfig", func(w http.ResponseWriter, r *http.Request) {
		if r.Method != http.MethodPost {
			w.WriteHeader(http.StatusMethodNotAllowed)
			return
		}

		var req incoming
		body, err := ioutil.ReadAll(r.Body)
		if err != nil {
			log.Printf("Error reading body: %v", err)
			http.Error(w, "can't read body", http.StatusBadRequest)
			return
		}
		err = json.Unmarshal(body, &req)
		if err != nil {
			http.Error(w, "Failed to parse JSON"+err.Error(), http.StatusBadRequest)
			return
		}

		change := false
		configOverride := []config{}
		for _, conf := range req.Configuration {
			originalPipeline := pipeline{}
			err := yaml.Unmarshal([]byte(conf.Data), &originalPipeline)
			if err != nil {
				http.Error(w, "Failed to parse yaml"+err.Error(), http.StatusBadRequest)
			}
			if originalPipeline.Extend != "" {
				resp, err := http.Get(originalPipeline.Extend)
				if err != nil {
					http.Error(w, "Failed to download extend pipeline: "+err.Error(), http.StatusBadRequest)
					return
				}
				if resp.StatusCode != 200 {
					http.Error(w, "Failed to download extend pipeline: "+resp.Status, http.StatusBadRequest)
					return
				}

				body, err := ioutil.ReadAll(resp.Body)
				if err != nil {
					http.Error(w, "Failed to download extend pipeline: "+err.Error(), http.StatusBadRequest)
					return
				}
				splited := strings.Split(originalPipeline.Extend, "/")
				confName := splited[len(splited)-1]
				configOverride = append(configOverride, config{Name: confName, Data: string(body)})
				change = true
			}

		}
		if change {
			w.WriteHeader(http.StatusOK)
			err = json.NewEncoder(w).Encode(map[string]interface{}{"configs": configOverride})
			if err != nil {
				log.Printf("Error on encoding json %v\n", err)
			}
		} else {
			w.WriteHeader(http.StatusNoContent) // use default config
			// No need to write a response body
		}
	})

	err := http.ListenAndServe(":8000", nil)
	if err != nil {
		log.Fatalf("Error on listen: %v", err)
	}
}