package main

import (
	"crypto/sha1"
	"encoding/json"
	"fmt"
	"html"
	"io/ioutil"
	"log"
	"net/http"
	"strings"
	"time"
)

type ImageData struct {
	Type string `"json:type"`
	Url  string `"json:url"`
}

type PublicKeyData struct {
	Id           string `"json:id"`
	Owner        string `"json:owner"`
	PublicKeyPem string `"json:publicKeyPem"`
}

type UserInfo struct {
	Id                string        `"json:id"`
	Type              string        `"json:type"`
	Following         string        `"json:following"`
	Followers         string        `"json:followers"`
	Inbox             string        `"json:inbox"`
	Outbox            string        `"json:outbox"`
	Featured          string        `"json:featured"`
	PreferredUsername string        `"json:preferredUsername"`
	PublicKey         PublicKeyData `"json:publicKeyPem"`
	Name              string        `"json:name"`
	Summary           string        `"json:summary"`
	Url               string        `"json:Url"`

	//	ManuallyApprovesFollowers	string	`"json:manuallyApprovesFollowers"`
	//	Discoverable	bool	`"json:discoverable"`
}

type PostInfo struct {
	Id        string `"json:id"`
	Type      string `"json:type"`
	Published string `"json:published"`
	Url       string `"json:Url"`
	Content   string `"json:content"`
}

func fetch_user_info(http_client http.Client, uri string) (UserInfo, error) {
	var userinfo UserInfo

	//	http_client := http.Client{}
	req, err := http.NewRequest(http.MethodGet, uri, nil)
	if err != nil {
		return UserInfo{}, err
	}

	req.Header.Set("Accept", "application/ld+json")

	resp, err := http_client.Do(req)
	if err != nil {
		return UserInfo{}, err
	}
	defer resp.Body.Close()

	err = json.NewDecoder(resp.Body).Decode(&userinfo)
	if err != nil {
		return UserInfo{}, err
	}

	return userinfo, nil
}

func fetch_post(http_client http.Client, uri string) (PostInfo, error) {
	var postinfo PostInfo

	req, err := http.NewRequest(http.MethodGet, uri, nil)
	if err != nil {
		return PostInfo{}, err
	}

	req.Header.Set("Accept", "application/ld+json")

	resp, err := http_client.Do(req)
	if err != nil {
		return PostInfo{}, err
	}
	defer resp.Body.Close()

	err = json.NewDecoder(resp.Body).Decode(&postinfo)
	if err != nil {
		return PostInfo{}, err
	}

	return postinfo, nil
}

func PollMastodonPleroma(endpoint string, reportPostChan chan ReportPost, http_client http.Client) {
	newposts := make([]ReportPost, 0)

	min_id := ""

	parsing_error := 0
	unprocess_error := 0
	use_auth := false

	var last_refresh int64
	var client_id string
	var client_secret string
	var oauthData OAuth
	var err error

	for _, extaccount := range settings.Externalaccounts {
		if extaccount.Endpoint == endpoint {
			use_auth = true
			client_id, client_secret, err = get_client(endpoint, &http_client)
			if err != nil {
				log.Fatal("Unable to register client: ", err)
			}

			oauthData, err = oauth_login(endpoint, extaccount.Username, extaccount.Password, client_id, client_secret)
			if err != nil {
				log.Print("Unable to login: ", err)
				return
			}
			last_refresh = time.Now().Unix()

		}
	}

	for {
		ri_mutex.Lock()
		m := runninginstances[endpoint]
		ri_mutex.Unlock()

		api_timeline := "https://" + endpoint + "/api/v1/timelines/public?limit=40&since_id=" + min_id
		req, err := http.NewRequest("GET", api_timeline, nil)
		if err != nil {
			log.Print("Unable to create new request")
			return
		}

		if use_auth == true {
			if time.Now().Unix() > last_refresh+oauthData.Expires_in {
				oauthData, err = oauth_refresh(endpoint, client_id, client_secret, oauthData.Refresh_token)
				if err != nil {
					log.Print("Unable to refresh: ", err)
					return
				}
				last_refresh = time.Now().Unix()
			}
			req.Header.Add("Authorization", oauthData.Access_token)
		}

		m.LastRun = time.Now().Format(time.RFC3339)
		resp, err := http_client.Do(req)
		if err != nil {
			m.Status = CLIENT_ISSUE
			ri_mutex.Lock()
			runninginstances[endpoint] = m
			ri_mutex.Unlock()
			log.Fatal("Failure here", err.Error())
			return
		}

		if resp.StatusCode == TOOMANYREQUESTS { // Short Delay, 30 seconds
			log.Print("Delaying "+endpoint+", gave status ", resp.StatusCode, ", 1 hour delay")
			_, _ = ioutil.ReadAll(resp.Body)
			resp.Body.Close() // Release as soon as done
			m.Status = resp.StatusCode
			ri_mutex.Lock()
			runninginstances[endpoint] = m
			ri_mutex.Unlock()
			if unprocess_error > 5 {
				log.Print("Exiting for " + endpoint)
			}
			unprocess_error = unprocess_error + 1
			time.Sleep(time.Second * 30)
			continue
		} else if resp.StatusCode == INTERNAL_ERROR { // Longer delay, 1 hour
			log.Print("Suspending "+endpoint+", gave status ", resp.StatusCode, ", 1 hour delay")
			_, _ = ioutil.ReadAll(resp.Body)
			resp.Body.Close() // Release as soon as done
			m.Status = 765
			ri_mutex.Lock()
			runninginstances[endpoint] = m
			ri_mutex.Unlock()
			time.Sleep(time.Second * 3600)
			continue
		} else if resp.StatusCode != 200 { // Crash
			log.Print("Terminating "+endpoint+", gave status ", resp.StatusCode)
			_, _ = ioutil.ReadAll(resp.Body)
			resp.Body.Close() // Release as soon as done
			m.Status = resp.StatusCode
			ri_mutex.Lock()
			runninginstances[endpoint] = m
			ri_mutex.Unlock()
			return
		}

		err = json.NewDecoder(resp.Body).Decode(&newposts)
		if err != nil {
			if parsing_error > 5 {
				m.Status = BAD_RESPONSE
				ri_mutex.Lock()
				runninginstances[endpoint] = m
				ri_mutex.Unlock()
				log.Print("Giving up on " + endpoint)
				return
			}
			parsing_error = parsing_error + 1
			time.Sleep(time.Second * 30)
		}
		resp.Body.Close() // Release as soon as done

		m.Status = RUNNING
		ri_mutex.Lock()
		runninginstances[endpoint] = m
		ri_mutex.Unlock()

		for _, newpost := range newposts {
			if newpost.Account.Acct == "" {
				continue
			}
			at_sign := strings.Index(newpost.Account.Acct, "@")
			newinstance := newpost.Account.Acct[at_sign+1:]

			// Trust the post if it comes from the same source
			if newinstance != endpoint {
				ri_mutex.Lock()
				o, exist := runninginstances[newinstance]
				ri_mutex.Unlock()
				if exist == false {
					o := RunningInstance{}
					new_client := http.Client{}
					o.client = new_client
					o.Status = KEEPALIVE
					ri_mutex.Lock()
					runninginstances[newinstance] = o
					ri_mutex.Unlock()
				}

				realuser, err := fetch_user_info(o.client, newpost.Account.Url)
				if err != nil {
					continue
				}
				realpost, err := fetch_post(o.client, newpost.Uri)
				if err != nil {
					continue
				}

				// Minor verification for now...
				newpost.Account.Display_name = realuser.Name
				newpost.Content = realpost.Content
				newpost.Created_at = realpost.Published
			}

			posthash := sha1.New()

			if at_sign == -1 {
				at_sign = len(newpost.Account.Acct)
				newpost.Account.Acct += "@" + endpoint
			}

			// Calculate the post hash
			fmt.Fprint(posthash, newpost.Uri)
			fmt.Fprint(posthash, newpost.normalized)
			fmt.Fprint(posthash, newpost.Account.Acct)
			fmt.Fprint(posthash, newpost.Account.Display_name)
			newpost.posthash = posthash.Sum(nil)

			newpost.normalized = html.UnescapeString(strings.ToLower(p.Sanitize(newpost.Content)))
			newpost.normalized = strings.ReplaceAll(newpost.normalized, "\t", " ")
			newpost.normalized = spaceReg.ReplaceAllString(newpost.normalized, " ")

			// Validate time
			t, err := time.Parse(time.RFC3339, newpost.Created_at)
			if err != nil {
				newpost.Created_at = time.Now().Format(time.RFC3339)
			}
			if t.Unix() < 0 {
				newpost.Created_at = time.Now().Format(time.RFC3339)
			}

			t, err = time.Parse(time.RFC3339, newpost.Account.Created_at)
			if err != nil {
				newpost.Account.Created_at = time.Now().Format(time.RFC3339)
			}
			if t.Unix() < 0 {
				newpost.Account.Created_at = time.Now().Format(time.RFC3339)
			}

			reportPostChan <- newpost

			// Check min_id
			if newpost.Id > min_id {
				min_id = newpost.Id
			}

			// Only done if we are crawling
			if settings.Crawl == true && stringexists(endpoint, settings.Banned) == false {
				// Skip over this if its the same as the endpoint
				if newinstance == endpoint {
					continue
				}
				ri_mutex.Lock()
				o, exists := runninginstances[newinstance]
				if exists == false || o.Status == KEEPALIVE {
					m := RunningInstance{}
					runninginstances[newinstance] = m
					go StartInstance(newinstance, reportPostChan)
				}

				ri_mutex.Unlock()
			}
		}
		time.Sleep(time.Second * 10)
	}
}