raven/server/AyaNova/Controllers/ReportController.cs

using System.Threading.Tasks;
using Microsoft.AspNetCore.Http;
using System.IO;
using Microsoft.AspNetCore.Mvc;
using Microsoft.AspNetCore.Routing;
using Microsoft.AspNetCore.Authorization;
using Microsoft.Extensions.Logging;
using AyaNova.Models;
using AyaNova.Api.ControllerHelpers;
using AyaNova.Biz;
using AyaNova.Util;

using PuppeteerSharp;

namespace AyaNova.Api.Controllers
{
    [ApiController]
    [ApiVersion("8.0")]
    [Route("api/v{version:apiVersion}/report")]
    [Produces("application/json")]
    [Authorize]
    public class ReportController : ControllerBase
    {
        private readonly AyContext ct;
        private readonly ILogger<ReportController> log;
        private readonly ApiServerState serverState;

        /// <summary>
        /// ctor
        /// </summary>
        /// <param name="dbcontext"></param>
        /// <param name="logger"></param>
        /// <param name="apiServerState"></param>  
        public ReportController(AyContext dbcontext, ILogger<ReportController> logger, ApiServerState apiServerState)
        {
            ct = dbcontext;
            log = logger;
            serverState = apiServerState;
        }



        [HttpGet("render-test")]
        [AllowAnonymous]
        public async Task<IActionResult> GetTestReport([FromRoute] string test)
        {
            if (!serverState.IsOpen)
                return StatusCode(503, new ApiErrorResponse(serverState.ApiErrorCode, null, serverState.Reason));

            string outputFile = FileUtil.NewRandomTempFilesFolderFileName;

            switch (test)
            {
                case "chrome-reddit-to-pdf":
                    //first test, just render a web page to pdf and return it
                    //return PhysicalFile(filePath, mimetype, dbObject.DisplayFileName);
                    outputFile += ".pdf";
                    //http://www.puppeteersharp.com/api/index.html
                    //https://github.com/hardkoded/puppeteer-sharp
                    await new BrowserFetcher().DownloadAsync(BrowserFetcher.DefaultRevision);
                    var browser = await Puppeteer.LaunchAsync(new LaunchOptions
                    {
                        Headless = true
                    });
                    var page = await browser.NewPageAsync();
                    await page.GoToAsync("https://github.com/hardkoded/puppeteer-sharp");

                    await page.PdfAsync(outputFile);
                    return PhysicalFile(outputFile, "application/pdf");
            }
            return NotFound(test);
        }



        //---------------------------------------------------------------------
        [HttpGet("poc")]
        [AllowAnonymous]
        public async Task<IActionResult> ProofOfConcept([FromRoute] string url)
        {
            if (!serverState.IsOpen)
                return StatusCode(503, new ApiErrorResponse(serverState.ApiErrorCode, null, serverState.Reason));

            var ReportJSFolderPath = Path.Combine(ServerBootConfig.AYANOVA_CONTENT_ROOT_PATH, "resource", "reportjs");
            if (!Directory.Exists(ReportJSFolderPath))
                throw new System.Exception($"E1012: \"reportjs\" folder not found where expected: \"{ReportJSFolderPath}\", installation damaged?");


            var hbspath = Path.Combine(ReportJSFolderPath, "ayhandlebars.js");
            if (!System.IO.File.Exists(hbspath))
                throw new System.Exception($"E1012: \"ayhandlebars.js\" file not found where expected: \"{hbspath}\", installation damaged?");


            await new BrowserFetcher().DownloadAsync(BrowserFetcher.DefaultRevision);

            //sample CSS
            var reportCSS = @"
            @page {
            margin: 1cm;
            }

            @page :first {
            margin: 2cm;
            }
            
            .ay-red {
            color:red;
            }
             .ay-blue {
            color:blue;
            }
            ";

            //sample template
            //var reportTemplate = "'<div>{{#with person}}<span class=\"ay-red\">{{firstname}}</span>  {{aycaps lastname}}{{/with}}</div>'";
            var reportTemplate = "'<!DOCTYPE html><html><head><title>test title</title></head><body><h1>Test page top</h1><p class=\"ay-blue\">A blue paragraph</p><div>{{#with person}}<span class=\"ay-red\">{{firstname}}</span>  {{aycaps lastname}}{{/with}}</div></body></html>'";

            //data object        
            var reportData = "{ person: { firstname: 'Tyler', lastname: 'Mott' } }";

            using (var browser = await Puppeteer.LaunchAsync(new LaunchOptions { Headless = true }))
            using (var page = await browser.NewPageAsync())
            {
                //Add handlebars JS for compiling and presenting
                await page.AddScriptTagAsync(new AddTagOptions() { Path = hbspath });

                //test add helpers
                await page.AddScriptTagAsync(new AddTagOptions() { Path = Path.Combine(ReportJSFolderPath, "ay-hb-helpers.js") });



                //execute to add to handlebars
                await page.EvaluateExpressionAsync("ayRegisterHelpers();");

                //compile and run handlebars template              
                var compileScript = $"Handlebars.compile({reportTemplate})({reportData});";
                var resultHTML = await page.EvaluateExpressionAsync<string>(compileScript);

                //render report as HTML              
                await page.SetContentAsync(resultHTML);

                //add style (after page or it won't work)
                await page.AddStyleTagAsync(new AddTagOptions { Content = reportCSS });

                //useful for debugging purposes only
                //var pagecontent = await page.GetContentAsync();

                //render to pdf and return
                var pdfBuffer = await page.PdfDataAsync();
                return new FileContentResult(pdfBuffer, "application/pdf");

            }

        }


        //-----------------------------------------



        //------------
        /*
        NOTES/TODO during testing

        Need job to automatically erase any temp files older than 5 minutes (or whatever)

        */

    }//eoc
}//eons