package main

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

type HnStories struct {
	Stories []HnItem
	Items   []int
}
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"`
}

const apiUrl string = "https://hacker-news.firebaseio.com/v0"

func (h *HnStories) populateStories(numstories int, done chan bool, widget *widgets.Gauge) {
	var item string
	var itemUrl string
	var counter int = 1
	for _, id := range h.Items[:numstories] {
		item = strconv.Itoa(id)
		itemUrl = apiUrl + "/item/" + item + ".json"
		timeout := time.Duration(5 * 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 item HnItem

		json.Unmarshal(storydata, &item)

		h.Stories = append(h.Stories, HnItem{
			By:    item.By,
			Id:    item.Id,
			Added: item.Added,
			Title: item.Title,
			Type:  item.Type,
			Url:   item.Url,
			Kids:  item.Kids,
		})
		counter++
		fcounter := float64(counter)
		fnumstories := float64(numstories)
		percentage := (fcounter / fnumstories) * 100
		widget.Percent = int(percentage)
		termui.Render(widget)
	}
	widget.Percent = 100
	done <- true
}
func (h *HnStories) httpHNFetchIds(url string, done chan bool) {
	timeout := time.Duration(5 * time.Second)
	client := &http.Client{
		Timeout: timeout,
	}
	request, err := http.NewRequest("GET", url, 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(numstories int, done chan []string) {
	counter := 1
	var termuiitems []string
	for _, item := range h.Stories[:numstories] {
		itemstring := fmt.Sprintf("%-6s %-6s | %d comments", "["+strconv.Itoa(counter)+".](fg:white,bold)", "["+item.Title+"](fg:green)", len(item.Kids))
		termuiitems = append(termuiitems, itemstring)
		counter++
	}
	done <- termuiitems
}

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
	hnurl := apiUrl + "/topstories.json"
	var a HnStories
	var numstories = 10
	done1 := make(chan bool, 10)
	done2 := make(chan bool, 10)
	g0.Percent = 1
	termui.Render(g0)
	go a.httpHNFetchIds(hnurl, done1)
	<-done1
	go a.populateStories(numstories, done2, g0)
	<-done2
	termui.Clear()
	l := widgets.NewList()
	//l.Title = "[Y] hacker news"
	termuiitems := make(chan []string, numstories)
	go a.httpHNDisplayStories(numstories, termuiitems)
	l.Border = false
	l.SetRect(0, 1, x, y)
	l.Rows = <-termuiitems
	l.TextStyle = termui.NewStyle(termui.ColorYellow)
	l.WrapText = true
	x, y = termui.TerminalDimensions()
	renderTab := func() {
		switch tabpane.ActiveTabIndex {
		case 0:
			termui.Render(tabpane, l)
		}
	}
	termui.Render(tabpane, l)

	previousKey := ""
	uiEvents := termui.PollEvents()
	for {
		e := <-uiEvents
		switch e.ID {
		case "h":
			tabpane.FocusLeft()
			termui.Clear()
			termui.Render(tabpane, l)
			renderTab()
		case "l":
			tabpane.FocusRight()
			termui.Clear()
			termui.Render(tabpane, l)
			renderTab()
		case "q", "<C-c>":
			return
		case "j", "<Down>":
			l.ScrollDown()
		case "k", "<Up>":
			l.ScrollUp()
		case "<C-d>":
			l.ScrollHalfPageDown()
		case "<C-u>":
			l.ScrollHalfPageUp()
		case "<C-f>":
			l.ScrollPageDown()
		case "<C-b>":
			l.ScrollPageUp()
		case "g":
			if previousKey == "g" {
				l.ScrollTop()
			}
		case "<Home>":
			l.ScrollTop()
		case "G", "<End>":
			l.ScrollBottom()
		case "<Resize>":
			payload := e.Payload.(termui.Resize)
			l.SetRect(0, 1, payload.Width, payload.Height)
			termui.Clear()
			termui.Render(l)
		}

		if previousKey == "g" {
			previousKey = ""
		} else {
			previousKey = e.ID
		}

		termui.Render(l, tabpane)
	}
}