package main

import (
	"bytes"
	"fmt"
	"os"
	"os/exec"
	"path"
	"strconv"
	"strings"

	"github.com/PuerkitoBio/goquery"
	"golang.org/x/net/html"
	"golang.org/x/net/html/atom"
)

const additionalCSS = `
details { margin-top: 20px; }
summary { margin-left: 20px; cursor: pointer; }
#footer > p, #footer > li {	max-width: none; word-wrap: normal; }
`

const footerText = `Generated by <a href="https://godoc.org/golang.org/x/tools/godoc" target="_blank">godoc</a> + <a href="https://code.rocket9labs.com/tslocum/godoc-static" target="_blank">godoc-static</a>`

func topBar(basePath string, siteName string) string {
	var index string
	if linkIndex {
		index = "index.html"
	}

	return `<div class="container">
<div class="top-heading" id="heading-wide"><a href="` + basePath + index + `">` + siteName + `</a></div>
<div class="top-heading" id="heading-narrow"><a href="` + basePath + index + `">` + siteName + `</a></div>
<!--<a href="#" id="menu-button"><span id="menu-button-arrow">&#9661;</span></a>-->
<div id="menu">
<a href="` + basePath + index + `" style="margin-right: 10px;">Package Index</a>
</div>
</div>`
}

func siteFooterText(basePath string) string {
	footer := siteFooter
	addP := footer != ""

	if addP {
		footer += "<p>"
	}

	if siteZip != "" {
		footer += `<a href="` + basePath + siteZip + `">Download ` + siteZip + `</a> to browse offline - `
	}
	footer += footerText

	if addP {
		footer += "</p>"
	}
	return footer
}

func updatePage(doc *goquery.Document, basePath string, siteName string) {
	doc.Find("link").Remove()
	doc.Find("script").Remove()

	linkTag := &html.Node{
		Type:     html.ElementNode,
		DataAtom: atom.Link,
		Data:     "link",
		Attr: []html.Attribute{
			{Key: "type", Val: "text/css"},
			{Key: "rel", Val: "stylesheet"},
			{Key: "href", Val: basePath + "lib/style.css"},
		},
	}

	doc.Find("head").AppendNodes(linkTag)

	doc.Find("#topbar").First().SetHtml(topBar(basePath, siteName))

	importPathDisplay := doc.Find("#short-nav").First().Find("code").First()
	if importPathDisplay.Length() > 0 {
		importPathDisplayText := importPathDisplay.Text()
		if strings.ContainsRune(importPathDisplayText, '.') && strings.HasPrefix(importPathDisplayText, `import "`) && strings.HasSuffix(importPathDisplayText, `"`) {
			importPath := importPathDisplayText[8 : len(importPathDisplayText)-1]

			browseImportPath := importPath
			var browseInsert string
			if strings.HasPrefix(importPath, "gitlab.com/") {
				browseInsert = "/-/tree/master"
			} else if strings.HasPrefix(importPath, "github.com/") || strings.HasPrefix(importPath, "git.sr.ht/") {
				browseInsert = "/tree/master"
			} else if strings.HasPrefix(importPath, "bitbucket.org/") || strings.HasPrefix(importPath, "code.rocket9labs.com/") {
				browseInsert = "/src/master"
			}
			if browseInsert != "" {
				var insertPos int
				var found int
				for i, c := range importPath {
					if c == '/' {
						found++
						if found == 3 {
							insertPos = i
							break
						}
					}
				}
				if insertPos > 0 {
					browseImportPath = importPath[0:insertPos] + browseInsert + importPath[insertPos:]
				}
			}

			importPathDisplay.SetHtml(fmt.Sprintf(`import "<a href="https://` + browseImportPath + `" target="_blank">` + importPath + `</a>"`))
		}
	}

	doc.Find("a").Each(func(_ int, selection *goquery.Selection) {
		href := selection.AttrOr("href", "")
		
		var suffix string
		if (strings.HasPrefix(href, "/src/") || strings.HasPrefix(href, "/pkg/")) && path.Ext(href) != "" {
			suffix = ".html"
		} else if linkIndex && !(strings.HasPrefix(href, "#") || strings.HasPrefix(href, "?")) && path.Ext(href) == "" {
			suffix = "/index.html"
		}
		if suffix != "" {
			pos := strings.IndexAny(href, "?#")
			if pos >= 0 {
				href = strings.TrimRight(href[0:pos], "/") + suffix + href[pos:]
			} else {
				href = strings.TrimRight(href, "/") + suffix
			}
		}

		if strings.HasPrefix(href, "/src/") || strings.HasPrefix(href, "/pkg/") {
			if strings.HasPrefix(href, "/pkg/") {
				href = href[4:]
			}
			selection.SetAttr("href", basePath+href[1:])
		} else if suffix != ""{
			selection.SetAttr("href", href)
		}
	})

	doc.Find("div").Each(func(_ int, selection *goquery.Selection) {
		if selection.HasClass("toggle") {
			var summary string
			var err error
			selection.Find("div").Each(func(_ int, subSelection *goquery.Selection) {
				if subSelection.HasClass("collapsed") {
					summary, err = subSelection.Find("span.text").First().Html()
					if err != nil {
						summary = "Summary not available"
					}

					subSelection.Remove()
				}
			})

			selection.Find(".toggleButton").Remove()

			selection.PrependHtml(fmt.Sprintf("<summary>%s</summary>", summary))

			selection.RemoveClass("toggle")

			selection.Nodes[0].Data = "details"
			selection.Nodes[0].DataAtom = atom.Details
		}
	})

	doc.Find("#footer").Last().SetHtml(siteFooterText(basePath))
}

func writeIndex(buf *bytes.Buffer, pkgs []string, filterPkgs []string) error {
	var index string
	if linkIndex {
		index = "/index.html"
	}

	buf.Reset()
	buf.WriteString(`<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<meta name="theme-color" content="#375EAB">
<title>` + siteName + `</title>
<link type="text/css" rel="stylesheet" href="lib/style.css">
</head>
<body>

<div id="lowframe" style="position: fixed; bottom: 0; left: 0; height: 0; width: 100%; border-top: thin solid grey; background-color: white; overflow: auto;">
...
</div><!-- #lowframe -->

<div id="topbar" class="wide">` + topBar("", siteName) + `</div>
<div id="page" class="wide">
<div class="container">
`)

	if siteDescription != "" {
		buf.WriteString(siteDescription)
	}

	buf.WriteString(`
<h1>
	Packages
</h1>
<div class="pkg-dir">
	<table>
		<tr>
			<th class="pkg-name">Name</th>
			<th class="pkg-synopsis">Synopsis</th>
		</tr>
`)

	var padding int
	var lastPkg string
	var pkgBuf bytes.Buffer
	for _, pkg := range pkgs {
		pkgBuf.Reset()
		cmd := exec.Command("go", "list", "-find", "-f", `{{ .Doc }}`, pkg)
		cmd.Env = godocEnv
		cmd.Dir = os.TempDir()
		cmd.Stdout = &pkgBuf
		setDeathSignal(cmd)

		cmd.Run() // Ignore error

		pkgLabel := pkg
		if lastPkg != "" {
			lastPkgSplit := strings.Split(lastPkg, "/")
			pkgSplit := strings.Split(pkg, "/")
			shared := 0
			for i := range pkgSplit {
				if i < len(lastPkgSplit) && strings.ToLower(lastPkgSplit[i]) == strings.ToLower(pkgSplit[i]) {
					shared++
				}
			}

			padding = shared * 20
			pkgLabel = strings.Join(pkgSplit[shared:], "/")
		}
		lastPkg = pkg

		var linkPackage bool
		for _, filterPkg := range filterPkgs {
			if pkg == filterPkg {
				linkPackage = true
				break
			}
		}
		buf.WriteString(`
		<tr>
			<td class="pkg-name" style="padding-left: ` + strconv.Itoa(padding) + `px;">`)
		if !linkPackage {
			buf.WriteString(pkgLabel)
		} else {
			buf.WriteString(`<a href="` + pkg + index + `">` + pkgLabel + `</a>`)
		}
		buf.WriteString(`</td>
			<td class="pkg-synopsis">
				` + pkgBuf.String() + `
			</td>
		</tr>
`)
	}
	buf.WriteString(`
	</table>
</div>
<div id="footer">` + siteFooterText("") + `</div>
</div>
</div>
</body>
</html>
`)

	return writeFile(buf, "", "index.html")
}