open System

open System.IO

open System.Net

open Newtonsoft.Json

open Newtonsoft.Json.Linq

open Plotly.NET

let private script = lazy (

use stream = typeof<ChartBridge.Snapshot>.Assembly.GetManifestResourceStream("Plotly.NET.Verso.Renderer.js")

use reader = new StreamReader(stream)

reader.ReadToEnd())

let private encode (text: string) = WebUtility.HtmlEncode(text)

let error message =

$"<div class=\"plotly-net-verso\" data-plotly-state=\"error\"><div role=\"alert\">Plotly.NET: {encode message}</div></div>"

let render document (snapshot: ChartBridge.Snapshot) =

let id = "plotly-" + Guid.NewGuid().ToString("N")

let mode, url =

match snapshot.Reference with

| ChartBridge.Cdn url -> "cdn", url

| ChartBridge.Full -> "full", ""

| ChartBridge.NoReference -> "none", ""

| ChartBridge.Require -> "require", ""

let payload = JObject()

payload["id"] <- JValue(id)

payload["mode"] <- JValue(mode)

payload["url"] <- JValue(url)

// Keep the originating serializer's JSON intact (including date strings).

// Escape HTML delimiters before putting its raw JSON in an inline script.

let chartJson = snapshot.Json.Replace("<", "\\u003c").Replace(">", "\\u003e").Replace("&", "\\u0026")

payload["chart"] <- JRaw(chartJson)

let settings = JsonSerializerSettings(StringEscapeHandling = StringEscapeHandling.EscapeHtml)

let json = JsonConvert.SerializeObject(payload, Formatting.None, settings)

let library =

snapshot.PlotlySource

|> Option.map (fun source -> "<script type=\"text/javascript\">" + source + "</script>")

|> Option.defaultValue ""

let chart =

$"<div id=\"{id}\" class=\"plotly-net-verso\" data-plotly-state=\"loading\"></div>"

+ library

+ "<script type=\"text/javascript\">" + script.Value.Replace("/*PAYLOAD*/", json) + "</script>"

+ snapshot.Description

if document then

"<!DOCTYPE html><html><head><meta charset=\"" + encode snapshot.Charset

+ "\"><title>" + encode snapshot.Title + "</title><meta name=\"description\" content=\""

+ encode snapshot.DocumentDescription + "\">" + snapshot.Favicon + snapshot.HeadTags

+ "</head><body>" + chart + "</body></html>"

else snapshot.HeadTags + chart

/// Creates Verso cell HTML, loading Plotly asynchronously from the chart's CDN reference.

/// A Full reference embeds Plotly for offline use; NoReference uses an already loaded library.

let toVersoHTML (gChart: GenericChart) =

ChartBridge.capture false gChart |> Rendering.render false

/// Creates a complete HTML document with the originating chart's Plotly library embedded.

/// User-supplied head tags and chart resources are preserved and may require network access.

let toVersoHTMLOffline (gChart: GenericChart) =

ChartBridge.capture true gChart |> Rendering.render true