package api

import (
	"fmt"
	"log"
	"net/http"
	"strings"
	"time"

	"github.com/bosssauce/ponzu/content"
	"github.com/bosssauce/ponzu/system/admin/upload"
	"github.com/bosssauce/ponzu/system/db"
)

// Externalable accepts or rejects external POST requests to endpoints such as:
// /external/posts?type=Review
type Externalable interface {
	// Accepts determines whether a type will allow external submissions
	Accepts() bool
}

// Mergeable allows external post content to be approved and published through
// the public-facing API
type Mergeable interface {
	// Approve copies an external post to the internal collection and triggers
	// a re-sort of its content type posts
	Approve() error
}

func externalPostsHandler(res http.ResponseWriter, req *http.Request) {
	if req.Method != http.MethodPost {
		res.WriteHeader(http.StatusMethodNotAllowed)
		return
	}

	err := req.ParseMultipartForm(1024 * 1024 * 4) // maxMemory 4MB
	if err != nil {
		log.Println("[External] error:", err)
		res.WriteHeader(http.StatusInternalServerError)
		return
	}

	t := req.URL.Query().Get("type")
	if t == "" {
		res.WriteHeader(http.StatusBadRequest)
		return
	}

	p, found := content.Types[t]
	if !found {
		log.Println("[External] attempt to submit unknown type:", t, "from:", req.RemoteAddr)
		res.WriteHeader(http.StatusNotFound)
		return
	}

	post := p()

	ext, ok := post.(Externalable)
	if !ok {
		log.Println("[External] rejected non-externalable type:", t, "from:", req.RemoteAddr)
		res.WriteHeader(http.StatusBadRequest)
		return
	}

	if ext.Accepts() {
		ts := fmt.Sprintf("%d", time.Now().Unix()*1000)
		req.PostForm.Set("timestamp", ts)
		req.PostForm.Set("updated", ts)

		urlPaths, err := upload.StoreFiles(req)
		if err != nil {
			log.Println(err)
			res.WriteHeader(http.StatusInternalServerError)
			return
		}

		for name, urlPath := range urlPaths {
			req.PostForm.Add(name, urlPath)
		}

		// check for any multi-value fields (ex. checkbox fields)
		// and correctly format for db storage. Essentially, we need
		// fieldX.0: value1, fieldX.1: value2 => fieldX: []string{value1, value2}
		var discardKeys []string
		for k, v := range req.PostForm {
			if strings.Contains(k, ".") {
				key := strings.Split(k, ".")[0]

				if req.PostForm.Get(key) == "" {
					req.PostForm.Set(key, v[0])
					discardKeys = append(discardKeys, k)
				} else {
					req.PostForm.Add(key, v[0])
				}
			}
		}

		for _, discardKey := range discardKeys {
			req.PostForm.Del(discardKey)
		}

		_, err = db.SetContent(t+"_pending:-1", req.PostForm)
		if err != nil {
			log.Println("[External] error:", err)
			res.WriteHeader(http.StatusInternalServerError)
			return
		}
	}
}