From 2eca89e6723c6540414e4ffbef0ac439fc0c9257 Mon Sep 17 00:00:00 2001
From: Xmader <xmader@outlook.com>
Date: Sun, 27 Dec 2020 23:51:37 -0500
Subject: [PATCH] feat: view score in LibreScore

---
 src/btn.ts             | 15 ++++++++++++---
 src/librescore-link.ts | 25 +++++++++++++++++++++++++
 src/main.ts            | 10 +++++++++-
 src/scoreinfo.ts       |  5 +++++
 4 files changed, 51 insertions(+), 4 deletions(-)
 create mode 100644 src/librescore-link.ts

diff --git a/src/btn.ts b/src/btn.ts
index 1047f8f..2acfd56 100644
--- a/src/btn.ts
+++ b/src/btn.ts
@@ -9,6 +9,11 @@ import btnListCss from './btn.css'
 
 type BtnElement = HTMLButtonElement
 
+export enum ICON {
+  DOWNLOAD = 'M9.6 2.4h4.8V12h2.784l-5.18 5.18L6.823 12H9.6V2.4zM19.2 19.2H4.8v2.4h14.4v-2.4z',
+  LIBRESCORE = 'm5.4837 4.4735v10.405c-1.25-0.89936-3.0285-0.40896-4.1658 0.45816-1.0052 0.76659-1.7881 2.3316-0.98365 3.4943 1 1.1346 2.7702 0.70402 3.8817-0.02809 1.0896-0.66323 1.9667-1.8569 1.8125-3.1814v-5.4822h8.3278v9.3865h9.6438v-2.6282h-6.4567v-12.417c-4.0064-0.015181-8.0424-0.0027-12.06-0.00676zm0.54477 2.2697h8.3278v1.1258h-8.3278v-1.1258z',
+}
+
 const getBtnContainer = (): HTMLDivElement => {
   const els = [...document.querySelectorAll('*')].reverse()
   const el = els.find(b => {
@@ -20,7 +25,7 @@ const getBtnContainer = (): HTMLDivElement => {
   return btnParent
 }
 
-const buildDownloadBtn = () => {
+const buildDownloadBtn = (icon: ICON) => {
   const btn = document.createElement('button')
   btn.type = 'button'
 
@@ -28,7 +33,7 @@ const buildDownloadBtn = () => {
   const svg = document.createElementNS('http://www.w3.org/2000/svg', 'svg')
   svg.setAttribute('viewBox', '0 0 24 24')
   const svgPath = document.createElementNS('http://www.w3.org/2000/svg', 'path')
-  svgPath.setAttribute('d', 'M9.6 2.4h4.8V12h2.784l-5.18 5.18L6.823 12H9.6V2.4zM19.2 19.2H4.8v2.4h14.4v-2.4z')
+  svgPath.setAttribute('d', icon)
   svgPath.setAttribute('fill', '#fff')
   svg.append(svgPath)
 
@@ -49,6 +54,7 @@ interface BtnOptions {
   readonly action: BtnAction;
   readonly disabled?: boolean;
   readonly tooltip?: string;
+  readonly icon?: ICON;
 }
 
 export enum BtnListMode {
@@ -62,7 +68,7 @@ export class BtnList {
   constructor (private getBtnParent: () => HTMLDivElement = getBtnContainer) { }
 
   add (options: BtnOptions): BtnElement {
-    const btnTpl = buildDownloadBtn()
+    const btnTpl = buildDownloadBtn(options.icon ?? ICON.DOWNLOAD)
     const setText = (btn: BtnElement) => {
       const textNode = btn.querySelector('span')
       return (str: string): void => {
@@ -186,10 +192,13 @@ export namespace BtnAction {
       const _url = await normalizeUrlInput(url)
       const a = document.createElement('a')
       a.href = _url
+      a.target = '_blank'
       a.dispatchEvent(new MouseEvent('click'))
     }, fallback, timeout)
   }
 
+  export const openUrl = download
+
   export const mscoreWindow = (scoreinfo: ScoreInfo, fn: (w: Window, score: WebMscore, processingTextEl: ChildNode) => any): BtnAction => {
     return async (btnName, btn, setText) => {
       const _onclick = btn.onclick
diff --git a/src/librescore-link.ts b/src/librescore-link.ts
new file mode 100644
index 0000000..04d8044
--- /dev/null
+++ b/src/librescore-link.ts
@@ -0,0 +1,25 @@
+import { assertRes, getFetch } from './utils'
+import { getMainCid } from './mscz'
+import { ScoreInfo } from './scoreinfo'
+
+const _getLink = (scorepack: string) => {
+  return `https://librescore.org/score/${scorepack}`
+}
+
+export const getLibreScoreLink = async (scoreinfo: ScoreInfo, _fetch = getFetch()): Promise<string> => {
+  const mainCid = await getMainCid(scoreinfo, _fetch)
+  const ref = scoreinfo.getScorepackRef(mainCid)
+  const url = `https://ipfs.infura.io:5001/api/v0/dag/get?arg=${ref}`
+
+  const r0 = await _fetch(url)
+  if (r0.status !== 500) {
+    assertRes(r0)
+  }
+  const res: { Message: string } | string = await r0.json()
+  if (typeof res !== 'string') {
+    // read further error msg
+    throw new Error(res.Message)
+  }
+
+  return _getLink(res)
+}
diff --git a/src/main.ts b/src/main.ts
index dc3459d..2b1037a 100644
--- a/src/main.ts
+++ b/src/main.ts
@@ -6,7 +6,8 @@ import { downloadPDF } from './pdf'
 import { downloadMscz } from './mscz'
 import { getFileUrl } from './file'
 import { INDV_DOWNLOADS } from './mscore'
-import { BtnList, BtnAction, BtnListMode } from './btn'
+import { getLibreScoreLink } from './librescore-link'
+import { BtnList, BtnAction, BtnListMode, ICON } from './btn'
 import { ScoreInfoInPage, SheetInfoInPage, getActualId } from './scoreinfo'
 import i18n from './i18n'
 
@@ -131,6 +132,13 @@ const main = (): void => {
     }),
   })
 
+  btnList.add({
+    name: 'View in LibreScore',
+    action: BtnAction.openUrl(() => getLibreScoreLink(scoreinfo)),
+    tooltip: 'BETA',
+    icon: ICON.LIBRESCORE,
+  })
+
   btnList.commit(BtnListMode.InPage)
 }
 
diff --git a/src/scoreinfo.ts b/src/scoreinfo.ts
index 4e67ee5..70059f4 100644
--- a/src/scoreinfo.ts
+++ b/src/scoreinfo.ts
@@ -4,6 +4,7 @@ import { getMainCid } from './mscz'
 
 export abstract class ScoreInfo {
   private readonly RADIX = 20;
+  private readonly INDEX_RADIX = 40;
 
   abstract id: number;
   abstract title: string;
@@ -25,6 +26,10 @@ export abstract class ScoreInfo {
   public getMsczCidUrl (mainCid: string): string {
     return `https://ipfs.infura.io:5001/api/v0/block/stat?arg=${this.getMsczIpfsRef(mainCid)}`
   }
+
+  public getScorepackRef (mainCid: string): string {
+    return `/ipfs/${mainCid}/index/${(+this.id) % this.INDEX_RADIX}/${this.id}/scorepack`
+  }
 }
 
 export class ScoreInfoObj extends ScoreInfo {