Add screenshot plugin (#217)

source/plugins/screenshot/index.mjs

@@ -0,0 +1,42 @@
+//Setup
+  export default async function({login, q, imports, data, account}, {enabled = false} = {}) {
+    //Plugin execution
+      try {
+        //Check if plugin is enabled and requirements are met
+          if ((!enabled)||(!q.screenshot))
+            return null
+
+        //Load inputs
+          let {url, selector, title, background} = imports.metadata.plugins.screenshot.inputs({data, account, q})
+          if (!url)
+            throw {error:{message:"An url is required"}}
+
+        //Start puppeteer and navigate to page
+          console.debug(`metrics/compute/${login}/plugins > screenshot > starting browser`)
+          const browser = await imports.puppeteer.launch()
+          console.debug(`metrics/compute/${login}/plugins > screenshot > started ${await browser.version()}`)
+          const page = await browser.newPage()
+          await page.setViewport({width:600, height:600})
+          console.debug(`metrics/compute/${login}/plugins > screenshot > loading ${url}`)
+          await page.goto(url)
+
+        //Screenshot
+          await page.waitForSelector(selector)
+          const clip = await page.evaluate(selector => {
+            const {x, y, width, height} = document.querySelector(selector).getBoundingClientRect()
+            return {x, y, width, height}
+          }, selector)
+          const [buffer] = await imports.record({page, ...clip, frames:1, background})
+          const screenshot = await (await imports.jimp.read(Buffer.from(buffer.split(",").pop(), "base64"))).resize(454, imports.jimp.AUTO)
+          await browser.close()
+
+        //Results
+          return {image:await screenshot.getBase64Async("image/png"), title, height:screenshot.bitmap.height, width:screenshot.bitmap.width}
+      }
+    //Handle errors
+      catch (error) {
+        if (error.error?.message)
+          throw error
+        throw {title:"Screenshot error", error:{message:"An error occured", instance:error}}
+      }
+  }