package activitypub

import (
	"bytes"
	"encoding/json"
	"errors"
	"fmt"
	"io/ioutil"
	"net/http"
	"regexp"
	"strings"
	"time"

	"github.com/FChannel0/FChannel-Server/config"
	"github.com/FChannel0/FChannel-Server/util"
)

func (activity Activity) AcceptFollow() Activity {
	var accept Activity
	accept.AtContext.Context = activity.AtContext.Context
	accept.Type = "Accept"
	var nActor Actor
	accept.Actor = &nActor
	accept.Actor.Id = activity.Object.Actor
	var nObj ObjectBase
	accept.Object = &nObj
	accept.Object.Actor = activity.Actor.Id
	var nNested NestedObjectBase
	accept.Object.Object = &nNested
	accept.Object.Object.Actor = activity.Object.Actor
	accept.Object.Object.Type = "Follow"
	accept.To = append(accept.To, activity.Object.Actor)

	return accept
}

func (activity Activity) AddFollowersTo() (Activity, error) {
	activity.To = append(activity.To, activity.Actor.Id)

	for _, e := range activity.To {
		reqActivity := Activity{Id: e + "/followers"}
		aFollowers, err := reqActivity.GetCollection()
		if err != nil {
			return activity, util.MakeError(err, "AddFollowersTo")
		}

		for _, k := range aFollowers.Items {
			activity.To = append(activity.To, k.Id)
		}
	}

	var nActivity Activity

	for _, e := range activity.To {
		var alreadyTo = false
		for _, k := range nActivity.To {
			if e == k || e == activity.Actor.Id {
				alreadyTo = true
			}
		}

		if !alreadyTo {
			nActivity.To = append(nActivity.To, e)
		}
	}

	activity.To = nActivity.To

	return activity, nil
}

func (activity Activity) CheckValid() (Collection, bool, error) {
	var respCollection Collection

	re := regexp.MustCompile(`.+\.onion(.+)?`)
	if re.MatchString(activity.Id) {
		activity.Id = strings.Replace(activity.Id, "https", "http", 1)
	}

	req, err := http.NewRequest("GET", activity.Id, nil)
	if err != nil {
		return respCollection, false, util.MakeError(err, "CheckValid")
	}

	req.Header.Set("Accept", config.ActivityStreams)

	resp, err := util.RouteProxy(req)
	if err != nil {
		return respCollection, false, util.MakeError(err, "CheckValid")
	}
	defer resp.Body.Close()

	body, _ := ioutil.ReadAll(resp.Body)

	if err := json.Unmarshal(body, &respCollection); err != nil {
		return respCollection, false, util.MakeError(err, "CheckValid")
	}

	if respCollection.AtContext.Context == "https://www.w3.org/ns/activitystreams" && respCollection.OrderedItems[0].Id != "" {
		return respCollection, true, nil
	}

	return respCollection, false, nil
}

func (activity Activity) GetCollection() (Collection, error) {
	var nColl Collection

	req, err := http.NewRequest("GET", activity.Id, nil)
	if err != nil {
		return nColl, util.MakeError(err, "GetCollection")
	}

	req.Header.Set("Accept", config.ActivityStreams)
	resp, err := util.RouteProxy(req)
	if err != nil {
		return nColl, util.MakeError(err, "GetCollection")
	}

	if resp.StatusCode == 200 {
		defer resp.Body.Close()
		body, _ := ioutil.ReadAll(resp.Body)
		if len(body) > 0 {
			if err := json.Unmarshal(body, &nColl); err != nil {
				return nColl, util.MakeError(err, "GetCollection")
			}
		}
	}

	return nColl, nil
}

func (activity Activity) IsLocal() (bool, error) {

	for _, e := range activity.To {
		if res, _ := GetActorFromDB(e); res.Id != "" {
			return true, nil
		}
	}

	for _, e := range activity.Cc {
		if res, _ := GetActorFromDB(e); res.Id != "" {
			return true, nil
		}
	}

	if activity.Actor != nil {
		if res, _ := GetActorFromDB(activity.Actor.Id); res.Id != "" {
			return true, nil
		}
	}

	return false, nil
}

func (activity Activity) Process() error {
	activityType := activity.Type

	if activityType == "Create" {
		for _, e := range activity.To {
			if res, err := GetActorFromDB(e); res.Id != "" {
				config.Log.Println("actor is in the database")
			} else if err != nil {
				return util.MakeError(err, "Process")
			} else {
				config.Log.Println("actor is NOT in the database")
			}
		}
	} else if activityType == "Follow" {
		// TODO: okay?
		return errors.New("not implemented")
	} else if activityType == "Delete" {
		return errors.New("not implemented")
	}

	return nil
}

func (activity Activity) Reject() Activity {
	var accept Activity
	accept.AtContext.Context = activity.AtContext.Context
	accept.Type = "Reject"
	var nObj ObjectBase
	accept.Object = &nObj
	var nActor Actor
	accept.Actor = &nActor
	accept.Actor.Id = activity.Object.Actor
	accept.Object.Actor = activity.Actor.Id
	var nNested NestedObjectBase
	accept.Object.Object = &nNested
	accept.Object.Object.Actor = activity.Object.Actor
	accept.Object.Object.Type = "Follow"
	accept.To = append(accept.To, activity.Actor.Id)

	return accept
}

func (activity Activity) Report(reason string) (bool, error) {
	if isLocal, err := activity.Object.IsLocal(); !isLocal || err != nil {
		return false, util.MakeError(err, "Report")
	}

	reqActivity := Activity{Id: activity.Object.Id}
	activityCol, err := reqActivity.GetCollection()

	if err != nil {
		return false, util.MakeError(err, "Report")
	}

	query := `insert into reported (id, count, board, reason) values ($1, $2, $3, $4)`
	if _, err = config.DB.Exec(query, activity.Object.Object.Id, 1, activityCol.Actor.Id, reason); err != nil {
		return false, util.MakeError(err, "Report")
	}

	return true, nil
}

func (activity Activity) SetActorFollower() (Activity, error) {
	var query string

	alreadyFollow, err := activity.Actor.IsAlreadyFollower(activity.Object.Actor)

	if err != nil {
		return activity, util.MakeError(err, "SetFollower")
	}

	activity.Type = "Reject"
	if activity.Actor.Id == activity.Object.Actor {
		return activity, nil
	}

	if alreadyFollow {
		query = `delete from follower where id=$1 and follower=$2`
		activity.Summary = activity.Object.Actor + " Unfollow " + activity.Actor.Id

		if _, err := config.DB.Exec(query, activity.Actor.Id, activity.Object.Actor); err != nil {
			return activity, util.MakeError(err, "SetFollower")
		}

		activity.Type = "Accept"
		return activity, util.MakeError(err, "SetFollower")
	}

	query = `insert into follower (id, follower) values ($1, $2)`
	activity.Summary = activity.Object.Actor + " Follow " + activity.Actor.Id

	if _, err := config.DB.Exec(query, activity.Actor.Id, activity.Object.Actor); err != nil {
		return activity, util.MakeError(err, "SetFollower")
	}

	activity.Type = "Accept"
	return activity, nil
}

func (activity Activity) SetActorFollowing() (Activity, error) {
	var query string

	alreadyFollowing := false
	alreadyFollower := false
	objActor, _ := GetActor(activity.Object.Actor)
	following, err := objActor.GetFollowing()

	if err != nil {
		return activity, util.MakeError(err, "SetActorFollowing")
	}

	actor, err := FingerActor(activity.Actor.Id)

	if err != nil {
		return activity, util.MakeError(err, "SetActorFollowing")
	}

	reqActivity := Activity{Id: actor.Followers}
	remoteActorFollowerCol, err := reqActivity.GetCollection()

	if err != nil {
		return activity, util.MakeError(err, "SetActorFollowing")
	}

	for _, e := range following {
		if e.Id == activity.Actor.Id {
			alreadyFollowing = true
		}
	}

	for _, e := range remoteActorFollowerCol.Items {
		if e.Id == activity.Object.Actor {
			alreadyFollower = true
		}
	}

	activity.Type = "Reject"

	if activity.Actor.Id == activity.Object.Actor {
		return activity, nil
	}

	if alreadyFollowing && alreadyFollower {
		query = `delete from following where id=$1 and following=$2`
		activity.Summary = activity.Object.Actor + " Unfollowing " + activity.Actor.Id

		if res, err := activity.Actor.IsLocal(); err == nil && !res {
			go activity.Actor.DeleteCache()
		} else {
			return activity, util.MakeError(err, "SetActorFollowing")
		}

		if _, err := config.DB.Exec(query, activity.Object.Actor, activity.Actor.Id); err != nil {
			return activity, util.MakeError(err, "SetActorFollowing")
		}

		activity.Type = "Accept"

		return activity, nil
	}

	if !alreadyFollowing && !alreadyFollower {

		query = `insert into following (id, following) values ($1, $2)`
		activity.Summary = activity.Object.Actor + " Following " + activity.Actor.Id

		if res, err := activity.Actor.IsLocal(); err == nil && !res {
			go activity.Actor.WriteCache()
		}
		if _, err := config.DB.Exec(query, activity.Object.Actor, activity.Actor.Id); err != nil {
			return activity, util.MakeError(err, "SetActorFollowing")
		}

		activity.Type = "Accept"

		return activity, nil
	}

	return activity, nil
}

func (activity Activity) MakeFollowingReq() (bool, error) {
	actor, err := GetActor(activity.Object.Id)

	if err != nil {
		return false, util.MakeError(err, "MakeFollowingReq")
	}

	req, err := http.NewRequest("POST", actor.Inbox, nil)

	if err != nil {
		return false, util.MakeError(err, "MakeFollowingReq")
	}

	resp, err := util.RouteProxy(req)

	if err != nil {
		return false, util.MakeError(err, "MakeFollowingReq")
	}

	defer resp.Body.Close()
	body, _ := ioutil.ReadAll(resp.Body)

	var respActivity Activity
	err = json.Unmarshal(body, &respActivity)

	return respActivity.Type == "Accept", util.MakeError(err, "MakeFollowingReq")
}

func (activity Activity) MakeRequestInbox() error {
	j, _ := json.MarshalIndent(activity, "", "\t")

	for _, e := range activity.To {
		if e != activity.Actor.Id {
			actor, err := FingerActor(e)

			if err != nil {
				return util.MakeError(err, "MakeRequest")
			}

			if actor.Id != "" {
				_, instance := GetActorAndInstance(actor.Id)

				if actor.Inbox != "" {
					req, err := http.NewRequest("POST", actor.Inbox, bytes.NewBuffer(j))

					if err != nil {
						return util.MakeError(err, "MakeRequest")
					}

					date := time.Now().UTC().Format(time.RFC1123)
					path := strings.Replace(actor.Inbox, instance, "", 1)
					re := regexp.MustCompile("https?://(www.)?")
					path = re.ReplaceAllString(path, "")
					sig := fmt.Sprintf("(request-target): %s %s\nhost: %s\ndate: %s", "post", path, instance, date)
					encSig, err := activity.Actor.ActivitySign(sig)

					if err != nil {
						return util.MakeError(err, "MakeRequest")
					}

					signature := fmt.Sprintf("keyId=\"%s\",headers=\"(request-target) host date\",signature=\"%s\"", activity.Actor.PublicKey.Id, encSig)

					req.Header.Set("Content-Type", config.ActivityStreams)
					req.Header.Set("Date", date)
					req.Header.Set("Signature", signature)
					req.Host = instance

					_, err = util.RouteProxy(req)

					if err != nil {
						return util.MakeError(err, "MakeRequest")
					}
				}
			}
		}
	}

	return nil
}

func (activity Activity) MakeRequestOutbox() error {
	j, _ := json.Marshal(activity)

	if activity.Actor.Outbox == "" {
		return util.MakeError(errors.New("invalid outbox"), "MakeRequestOutbox")
	}

	req, err := http.NewRequest("POST", activity.Actor.Outbox, bytes.NewBuffer(j))

	if err != nil {
		return util.MakeError(err, "MakeRequestOutbox")
	}

	re := regexp.MustCompile("https?://(www.)?")

	var instance string
	if activity.Actor.Id == config.Domain {
		instance = re.ReplaceAllString(config.Domain, "")
	} else {
		_, instance = GetActorAndInstance(activity.Actor.Id)
	}

	date := time.Now().UTC().Format(time.RFC1123)
	path := strings.Replace(activity.Actor.Outbox, instance, "", 1)
	path = re.ReplaceAllString(path, "")
	sig := fmt.Sprintf("(request-target): %s %s\nhost: %s\ndate: %s", "post", path, instance, date)
	encSig, err := activity.Actor.ActivitySign(sig)

	if err != nil {
		return util.MakeError(err, "MakeRequestOutbox")
	}

	signature := fmt.Sprintf("keyId=\"%s\",headers=\"(request-target) host date\",signature=\"%s\"", activity.Actor.PublicKey.Id, encSig)

	req.Header.Set("Content-Type", config.ActivityStreams)
	req.Header.Set("Date", date)
	req.Header.Set("Signature", signature)
	req.Host = instance

	_, err = util.RouteProxy(req)

	return util.MakeError(err, "MakeRequestOutbox")
}