package main

import "git.tebibyte.media/sashakoshka/skipper/dom"
import "git.tebibyte.media/sashakoshka/skipper/input"
import "git.tebibyte.media/sashakoshka/skipper/bookmarks"

import "fmt"
import "net/url"
import "strings"
import "git.sr.ht/~yotam/go-gemini"

func fetchBackward () {
	if page.loading { return }
	location := page.history.Backward()
	if location != nil {
		go fetchNoTrace(location)
	}
}

func fetchForward () {
	if page.loading { return }
	location := page.history.Forward()
	if location != nil {
		go fetchNoTrace(location)
	}
}

func fetch (location *url.URL) {
	fetchBack(location, false, true)
}

func fetchStringUrl (stringLocation string) {
	location, _ := url.Parse(stringLocation)
	fetch(location)
}

func fetchNoTrace (location *url.URL) {
	fetchBack(location, false, false)
}

func fetchSource (location *url.URL) {
	fetchBack(location, true, false)
}

func fetchBack (location *url.URL, viewSource bool, addToHistory bool) {
	if page.loading { return }

	page.loading = true
	page.readingInput = false
	page.readingUrlInput = false
	input.SelectNone()
	
	page.currentUrl = location
	if addToHistory {
		page.history.Add(location)
	}

	if location.Scheme == "about" {
		switch location.Opaque {
		case "skipper":
			fetchString(aboutGemtext, page.currentUrl)
		case "home":
			fetchString(homeGemtext, page.currentUrl)
		case "bookmarks":
			fetchString(bookmarks.Gemtext(), page.currentUrl)
		default:
			fetchString (
				"# Error\n\n" +
				"That page does not exist.",
				page.currentUrl)
		}
		page.loading = false
		redraw()
		application.Draw()
		return
	}
	
	redraw()
	application.Draw()

	response, err := client.Fetch(location.String())
	body := response.Body

	defer func () {
		if body != nil {
			body.Close()
		}
	} ()
	
	if err != nil {
		fetchString (
			"# Error\n\n" +
			"There was an error connecting to " +
			location.String() + "\n\n" +
			"> " + err.Error() + "\n",
			page.currentUrl)
		response.Status = 0
	}

	simpleStatus := gemini.SimplifyStatus(response.Status)

	if simpleStatus == gemini.StatusRedirect {
		page.redirectCounter ++
	} else {
		page.redirectCounter = 0
	}

	switch simpleStatus {
	case 0:
	case gemini.StatusInput:
		fetchString("# " + response.Meta, page.currentUrl)
		page.input.Reset()
		page.input.Obscure = response.Status == 11
		page.input.Select()
		page.readingInput = true
	
	case gemini.StatusSuccess:
		if body != nil {
			meta := strings.Split(response.Meta, ";")
			var mime string
			if len(meta) >= 1 {
				mime = meta[0]
			}

			if viewSource {
				setDocument(dom.ParseSource(body, page.currentUrl))
			} else if mime == "text/gemini" {
				setDocument(dom.ParseDocument(body, page.currentUrl))
			} else {
				setDocument(dom.ParseSource(body, page.currentUrl))
			}
		}

	case gemini.StatusRedirect:
		if page.redirectCounter > 8 {
			fetchString (fmt.Sprintf (
				"# Too many redirects\n\n" +
				"Enough! The site has redirected us too many " +
				"times."),
				page.currentUrl)
			break
		}
	
		location, err := url.Parse(response.Meta)
		if err != nil {
			fetchString (fmt.Sprintf (
				"# Error\n\n" +
				"The site responded with an invalid redirect:\n\n" +
				"%s",
				err.Error()), page.currentUrl)
		} else {
			page.history.Remove()
			defer func () {
				go fetchBack(location, viewSource, true)
			} ()
		}

	case gemini.StatusTemporaryFailure, gemini.StatusPermanentFailure:
		fetchString (fmt.Sprintf (
			"# Error %d\n\n" +
			"The site responded with an error:\n\n" +
			"> %s",
			response.Status, response.Meta), page.currentUrl)
			
	default:
		fetchString (fmt.Sprintf (
			"# Unhandled response status %d\n\n" +
			"Skipper doesn't know how to handle this type of " +
			"response yet.",
			response.Status), page.currentUrl)
	}
	
	page.loading = false
	redraw()
	application.Draw()
}

func fetchString (data string, location *url.URL) {
	setDocument(dom.ParseDocument(strings.NewReader(data), location))
}

func setDocument (document *dom.Document) {
	page.document = document
	page.scroll = 0
	application.SetTitle(document.Title() + " - Skipper")
}