package main

import (
	"github.com/microcosm-cc/bluemonday"
	"encoding/json"
	"crypto/sha1"
	"io/ioutil"
	"net/http"
	"strings"
	"regexp"
	"html"
	"time"
	"fmt"
	"log"
)

var p *bluemonday.Policy
var spaceReg *regexp.Regexp

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

	min_id := ""

	http_client := http.Client{}
	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
			register_client(endpoint, &http_client)

			client_id, client_secret, err = register_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 {
			ri_mutex.Lock()
			m.Status = CLIENT_ISSUE
			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
			ri_mutex.Lock()
			m.Status = resp.StatusCode
			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
			ri_mutex.Lock()
			m.Status = 765
			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
			ri_mutex.Lock()
			m.Status = resp.StatusCode
			runninginstances[endpoint] = m
			ri_mutex.Unlock()
			return
		}

		err = json.NewDecoder(resp.Body).Decode(&newposts)
		if err != nil {
			if parsing_error > 5 {
				ri_mutex.Lock()
				m.Status = BAD_RESPONSE
				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

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

		for _, newpost := range newposts {
			if newpost.Account.Acct == "" {
				continue
			}
			posthash := sha1.New()

			at_sign := strings.Index(newpost.Account.Acct, "@")

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

			// Calculate the post hash
			fmt.Fprint(posthash, newpost.Url)
			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 {
				newinstance := newpost.Account.Acct[at_sign+1:]
				ri_mutex.Lock()
				_, exists := runninginstances[newinstance]
				if exists == false {
					m := RunningInstance{}
					runninginstances[newinstance] = m
					go StartInstance(newinstance, reportPostChan)
				}

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

// Change this to return a proper "err"
func GetNodeInfo(endpoint string) (NodeInfo) {
	/* Checking order
	 * Mastodon/Pleroma
	 * Um..nothing else yet
	*/
	pleromastodon_nodeinfo_uri := "https://" + endpoint + "/nodeinfo/2.0.json"
	//http_client := http.Client{Timeout: 10 * time.Second}
	http_client := http.Client{}
	pleromastodon_api_resp, err := http_client.Get(pleromastodon_nodeinfo_uri)
	if err != nil {
		return NodeInfo{}
	} else {
		defer pleromastodon_api_resp.Body.Close()
	}

	if pleromastodon_api_resp.StatusCode == 200 {
		var nodeinfo NodeInfo
		err = json.NewDecoder(pleromastodon_api_resp.Body).Decode(&nodeinfo)
		if err == nil {
			defer pleromastodon_api_resp.Body.Close()
			return nodeinfo
		}
	}

	// Check the front page
	index_uri := "https://" + endpoint + "/"
	resp_index, err := http_client.Get(index_uri)
	if err != nil {
		log.Print("Unable to connect to " + endpoint + ", giving up")
		return NodeInfo{}
	}
	defer resp_index.Body.Close()
	indexbin, err := ioutil.ReadAll(resp_index.Body)
	if err != nil {
		log.Print("Unable to read index of " + endpoint + ", giving up")
		return NodeInfo{}
	}
	indexstr := string(indexbin)
	nodeinfo := NodeInfo{}
	if strings.Contains(indexstr, "Pleroma") || strings.Contains(indexstr, "Soapbox") {
		log.Print("Manual view: Pleroma" + endpoint)
		nodeinfo.Software.Name = "pleroma"
		nodeinfo.Software.Version = "guess"
	} else if strings.Contains(indexstr, "Mastodon") {
		log.Print("Manual view: Mastodon" + endpoint)
		nodeinfo.Software.Name = "mastodon"
		nodeinfo.Software.Version = "guess"
	} else if strings.Contains(indexstr, "Gab") {
		log.Print("Manual view: Gab" + endpoint)
		nodeinfo.Software.Name = "gab"
		nodeinfo.Software.Version = "guess"
	}

	return nodeinfo
}

func StartInstance(endpoint string, reportPostChan chan ReportPost) {
	nodeinfo := GetNodeInfo(endpoint)
	if nodeinfo.Software.Name == "" {
		var m = runninginstances[endpoint]
		m.Software = ""
		m.LastRun = time.Now().Format(time.RFC3339)
		m.Status = UNSUPPORTED_INSTANCE
		ri_mutex.Lock()
		runninginstances[endpoint] = m
		ri_mutex.Unlock()
		return
	}

	if nodeinfo.Software.Name == "pleroma" || nodeinfo.Software.Name == "mastodon" {
		log.Print("Starting " + endpoint + " as Mastodon/Pleroma instance")
		go PollMastodonPleroma(endpoint, reportPostChan)
	}

}