package main

import (
	"encoding/json"
	"fmt"
	termui "github.com/gizak/termui/v3"
	"github.com/gizak/termui/v3/widgets"
	"io/ioutil"
	"log"
	//	"math"
	"net/http"
	//"sort"
	"os/exec"
	"runtime"
	"strconv"
	"sync"
	"time"
)

type HnStories struct {
	Stories []HnItem
	Items   []int
	List    []string
}
type HnItem struct {
	By          string `json:"by,omitempty"`
	Descendants int    `json:"descendants,omitempty"`
	Id          int    `json:"id,omitempty"`
	Kids        []int  `json:"kids,omitempty"`
	Score       int    `json:"score,omitempty"`
	Added       int    `json:"time,omitempty"`
	Title       string `json:"title,omitempty"`
	Type        string `json:"type,omitempty"`
	Url         string `json:"url,omitempty"`
}

type LStories struct {
	Stories []LobsterItem
	List    []string
}

type LobsterItem struct {
	ShortID       string `json:"short_id"`
	ShortIDURL    string `json:"short_id_url"`
	CreatedAt     string `json:"created_at"`
	Title         string `json:"title"`
	Url           string `json:"url"`
	Score         int    `json:"score"`
	Upvotes       int    `json:"upvotes"`
	Downvotes     int    `json:"downvotes"`
	CommentCount  int    `json:"comment_count"`
	Description   string `json:"description"`
	CommentsURL   string `json:"comments_url"`
	SubmitterUser struct {
		Username      string `json:"username"`
		CreatedAt     string `json:"created_at"`
		IsAdmin       bool   `json:"is_admin"`
		About         string `json:"about"`
		IsModerator   bool   `json:"is_moderator"`
		Karma         int    `json:"karma"`
		AvatarURL     string `json:"avatar_url"`
		InvitedByUser string `json:"invited_by_user"`
	} `json:"submitter_user"`
	Tags []string `json:"tags"`
}

const apiUrlHN string = "https://hacker-news.firebaseio.com/v0"
const apiUrlL string = "https://lobste.rs/hottest.json"
const mpRSS string = "https://blog.acolyer.org/feed/"
const hnumstories int = 30
const lnumstories int = 25
const refreshrate time.Duration = 300

func (l *LStories) fetchLStories() {
	timeout := time.Duration(10 * time.Second)
	client := &http.Client{
		Timeout: timeout,
	}

	request, err := http.NewRequest("GET", apiUrlL, nil)
	if err != nil {
		log.Println(err)
	}
	response, err := client.Do(request)
	if err != nil {
		log.Println(err)
	}
	storydata, err := ioutil.ReadAll(response.Body)
	if err != nil {
		log.Println(err)
	}

	json.Unmarshal(storydata, &l.Stories)
}

func (h *HnStories) fetchHNStories(item string, wg *sync.WaitGroup) {
	defer wg.Done()
	var itemUrl string
	itemUrl = apiUrlHN + "/item/" + item + ".json"
	timeout := time.Duration(10 * time.Second)
	client := &http.Client{
		Timeout: timeout,
	}
	request, err := http.NewRequest("GET", itemUrl, nil)
	if err != nil {
		log.Println(err)
	}
	response, err := client.Do(request)
	if err != nil {
		log.Println(err)
	}
	storydata, err := ioutil.ReadAll(response.Body)
	if err != nil {
		log.Println(err)
	}

	var story HnItem

	json.Unmarshal(storydata, &story)

	h.Stories = append(h.Stories, HnItem{
		By:    story.By,
		Id:    story.Id,
		Added: story.Added,
		Title: story.Title,
		Type:  story.Type,
		Url:   story.Url,
		Kids:  story.Kids,
	})
}

func (h *HnStories) httpHNFetchIds(done chan bool) {
	timeout := time.Duration(5 * time.Second)
	client := &http.Client{
		Timeout: timeout,
	}
	request, err := http.NewRequest("GET", apiUrlHN+"/topstories.json", nil)
	if err != nil {
		log.Println(err)
	}
	response, err := client.Do(request)
	if err != nil {
		log.Println(err)
	}
	d := json.NewDecoder(response.Body)
	err = d.Decode(&h.Items)
	if err != nil {
		log.Println(err)
	}
	done <- true
}

func (h *HnStories) httpHNDisplayStories(wg *sync.WaitGroup) {
	wg.Add(1)
	var counter int = 1
	for _, item := range h.Stories[:hnumstories] {
		itemstring := fmt.Sprintf("%-6s %-6s | %d comments", "["+strconv.Itoa(counter)+".](fg:white,bold)", "["+item.Title+"](fg:green)", len(item.Kids))
		h.List = append(h.List, itemstring)
		counter++
	}
}
func (l *LStories) listLStories() {
	var counter int = 1
	for _, item := range l.Stories[:lnumstories] {
		itemstring := fmt.Sprintf("%-6s %-6s | %d comments", "["+strconv.Itoa(counter)+".](fg:white,bold)", "["+item.Title+"](fg:green)", item.CommentCount)
		l.List = append(l.List, itemstring)
		counter++
	}
}

func (h *HnStories) populateHNStories(gauge *widgets.Gauge, wg *sync.WaitGroup) {
	done := make(chan bool)
	go h.httpHNFetchIds(done)
	<-done
	var counter int = 1
	for _, item := range h.Items[:hnumstories] {
		wg.Add(1)
		go h.fetchHNStories(strconv.Itoa(item), wg)
		fcounter := float64(counter)
		fnumstories := float64(hnumstories)
		percentage := (fcounter / fnumstories) * 100
		gauge.Percent = int(percentage)
		termui.Render(gauge)
		counter++
	}
	wg.Wait()
	go h.httpHNDisplayStories(wg)
	wg.Wait()
}
func (h *HnStories) clearHNStruct() {
	h = nil
}
func (l *LStories) clearLStruct() {
	l = nil
}

func main() {
	if err := termui.Init(); err != nil {
		log.Fatalf("failed to initialize termui: %v", err)
	}
	defer termui.Close()
	x, y := termui.TerminalDimensions()
	tabpane := widgets.NewTabPane("[Y] Hacker News", "[L] Lobste.rs")
	tabpane.SetRect(0, 0, x, 1)
	tabpane.Border = false
	g0 := widgets.NewGauge()
	g0.Title = "Fetching Stories.."
	g0.SetRect(0, 3, x, 6)
	g0.BarColor = termui.ColorYellow
	g0.LabelStyle = termui.NewStyle(termui.ColorBlue)
	g0.BorderStyle.Fg = termui.ColorWhite
	g0.Percent = 1
	termui.Render(g0)
	var h HnStories
	var l LStories
	var wg sync.WaitGroup
	l.fetchLStories()
	l.listLStories()
	h.populateHNStories(g0, &wg)
	termui.Clear()
	hlist := widgets.NewList()
	hlist.Border = false
	x, y = termui.TerminalDimensions()
	hlist.SetRect(0, 1, x, y)
	hlist.TextStyle = termui.NewStyle(termui.ColorYellow)
	hlist.WrapText = true
	hlist.Rows = h.List

	llist := widgets.NewList()
	llist.Border = false
	x, y = termui.TerminalDimensions()
	llist.SetRect(0, 1, x, y)
	llist.TextStyle = termui.NewStyle(termui.ColorYellow)
	llist.WrapText = true
	llist.Rows = l.List
	renderTab := func() {
		switch tabpane.ActiveTabIndex {
		case 0:
			termui.Render(hlist)
		case 1:
			termui.Render(llist)
		}
	}
	termui.Render(tabpane, hlist)

	ticker := time.NewTicker(refreshrate * time.Second).C
	previousKey := ""
	uiEvents := termui.PollEvents()
	for {
		select {
		case e := <-uiEvents:
			switch e.ID {
			case "h", "<Left>":
				tabpane.FocusLeft()
				termui.Clear()
				termui.Render(tabpane)
				renderTab()
			case "l", "<Right>":
				tabpane.FocusRight()
				termui.Clear()
				termui.Render(tabpane)
				renderTab()
			case "q", "<Escape>", "<C-c>":
				return
			case "r":
				termui.Clear()
				if tabpane.ActiveTabIndex == 0 {
					h.clearHNStruct()
					g0.Title = "Refreshing HN Stories.."
					g0.Percent = 1
					var wg2 sync.WaitGroup
					h.populateHNStories(g0, &wg2)
					hlist := widgets.NewList()
					hlist.Border = false
					x, y = termui.TerminalDimensions()
					hlist.SetRect(0, 1, x, y)
					hlist.TextStyle = termui.NewStyle(termui.ColorYellow)
					hlist.WrapText = true
					hlist.Rows = h.List
				} else if tabpane.ActiveTabIndex == 1 {
					l.clearLStruct()
					g0.Title = "Refreshing Lobster Stories.."
					g0.Percent = 100
					termui.Render(g0)
					l.fetchLStories()
					l.listLStories()
					llist := widgets.NewList()
					llist.Border = false
					x, y = termui.TerminalDimensions()
					llist.SetRect(0, 1, x, y)
					llist.TextStyle = termui.NewStyle(termui.ColorYellow)
					llist.WrapText = true
					llist.Rows = l.List
				}
			case "j", "<Down>":
				if tabpane.ActiveTabIndex == 0 {
					hlist.ScrollDown()
				}
				if tabpane.ActiveTabIndex == 1 {
					llist.ScrollDown()
				}
			case "k", "<Up>":
				if tabpane.ActiveTabIndex == 0 {
					hlist.ScrollUp()
				}
				if tabpane.ActiveTabIndex == 1 {
					llist.ScrollUp()
				}
			case "<C-d>":
				if tabpane.ActiveTabIndex == 0 {
					hlist.ScrollHalfPageDown()
				}
				if tabpane.ActiveTabIndex == 1 {
					llist.ScrollHalfPageDown()
				}
			case "<C-u>":
				if tabpane.ActiveTabIndex == 0 {
					hlist.ScrollHalfPageUp()
				}
				if tabpane.ActiveTabIndex == 1 {
					llist.ScrollHalfPageUp()
				}
			case "<C-f>":
				if tabpane.ActiveTabIndex == 0 {
					hlist.ScrollPageDown()
				}
				if tabpane.ActiveTabIndex == 1 {
					llist.ScrollPageDown()
				}
			case "<C-b>":
				if tabpane.ActiveTabIndex == 0 {
					hlist.ScrollPageUp()
				}
				if tabpane.ActiveTabIndex == 1 {
					llist.ScrollPageUp()
				}
			case "g":
				if tabpane.ActiveTabIndex == 0 {
					hlist.ScrollDown()
				}
				if tabpane.ActiveTabIndex == 1 {
					llist.ScrollDown()
				}
				if previousKey == "g" {
					if tabpane.ActiveTabIndex == 0 {
						hlist.ScrollTop()
					} else if tabpane.ActiveTabIndex == 1 {
						llist.ScrollTop()
					}
				}
			case "<Home>":
				if tabpane.ActiveTabIndex == 0 {
					hlist.ScrollTop()
				}
				if tabpane.ActiveTabIndex == 1 {
					llist.ScrollTop()
				}
			case "G", "<End>":
				if tabpane.ActiveTabIndex == 0 {
					hlist.ScrollBottom()
				}
				if tabpane.ActiveTabIndex == 1 {
					llist.ScrollBottom()
				}
			case "<Enter>":
				if tabpane.ActiveTabIndex == 0 {
					url := h.Stories[hlist.SelectedRow].Url
					openbrowser(url)
				} else if tabpane.ActiveTabIndex == 1 {
					url := l.Stories[llist.SelectedRow].Url
					openbrowser(url)
				}
			case "<Resize>":
				payload := e.Payload.(termui.Resize)
				hlist.SetRect(0, 1, payload.Width, payload.Height)
				termui.Clear()
				termui.Render(tabpane, hlist, llist)
			}

			if previousKey == "g" {
				previousKey = ""
			} else {
				previousKey = e.ID
			}
			if tabpane.ActiveTabIndex == 0 {
				termui.Render(tabpane, hlist)
			} else if tabpane.ActiveTabIndex == 1 {
				termui.Render(tabpane, llist)
			}
		case <-ticker:
			termui.Clear()
			if tabpane.ActiveTabIndex == 0 {
				h.clearHNStruct()
				g0.Title = "Refreshing HN Stories.."
				g0.Percent = 1
				var wg2 sync.WaitGroup
				h.populateHNStories(g0, &wg2)
				hlist := widgets.NewList()
				hlist.Border = false
				x, y = termui.TerminalDimensions()
				hlist.SetRect(0, 1, x, y)
				hlist.TextStyle = termui.NewStyle(termui.ColorYellow)
				hlist.WrapText = true
				hlist.Rows = h.List
				termui.Render(tabpane, hlist)
			} else if tabpane.ActiveTabIndex == 1 {
				l.clearLStruct()
				g0.Title = "Refreshing Lobster Stories.."
				g0.Percent = 100
				termui.Render(g0)
				l.fetchLStories()
				l.listLStories()
				llist := widgets.NewList()
				llist.Border = false
				x, y = termui.TerminalDimensions()
				llist.SetRect(0, 1, x, y)
				llist.TextStyle = termui.NewStyle(termui.ColorYellow)
				llist.WrapText = true
				llist.Rows = l.List
				termui.Render(tabpane, llist)
			}
		}
	}
}

// Thanks https://gist.github.com/hyg/9c4afcd91fe24316cbf0
func openbrowser(url string) {
	var err error
	switch runtime.GOOS {
	case "linux", "freebsd":
		err = exec.Command("xdg-open", url).Start()
	case "windows":
		err = exec.Command("rundll32", "url.dll,FileProtocolHandler", url).Start()
	case "darwin":
		err = exec.Command("open", url).Start()
	default:
		err = fmt.Errorf("unsupported platform")
	}
	if err != nil {
		log.Fatal(err)
	}
}