From e7d78d59ecfc5174612bd97204832d920d8deef4 Mon Sep 17 00:00:00 2001
From: Alexandr Karpov <alexandr.d.karpov@gmail.com>
Date: Wed, 12 Apr 2023 13:14:34 +0300
Subject: [PATCH] added audio, video previews, fixed image previews

---
 akarpov/files/previews/__init__.py            |  21 +++-
 akarpov/files/previews/audio/__init__.py      |   1 +
 akarpov/files/previews/audio/basic.py         |  61 +++++++++++
 akarpov/files/previews/audio/waves.py         | 102 ++++++++++++++++++
 akarpov/files/previews/image/__init__.py      |   2 +-
 .../previews/image/{jpeg.py => basic.py}      |   5 +-
 akarpov/files/previews/video/mp4.py           |   2 +-
 akarpov/files/views.py                        |  15 ++-
 akarpov/templates/files/view.html             |   4 +-
 .../local/django/install_preview_dependencies |   2 +-
 10 files changed, 200 insertions(+), 15 deletions(-)
 create mode 100644 akarpov/files/previews/audio/__init__.py
 create mode 100644 akarpov/files/previews/audio/basic.py
 create mode 100644 akarpov/files/previews/audio/waves.py
 rename akarpov/files/previews/image/{jpeg.py => basic.py} (89%)

diff --git a/akarpov/files/previews/__init__.py b/akarpov/files/previews/__init__.py
index df2941f..e08a383 100644
--- a/akarpov/files/previews/__init__.py
+++ b/akarpov/files/previews/__init__.py
@@ -1,3 +1,20 @@
-from . import image, video
+from . import audio, image, video
 
-previews = {"video": {"mp4": video.mp4.view}, "image": {"jpeg": image.jpeg.view}}
+previews = {
+    "audio": {
+        "aac": audio.basic.view,
+        "mpeg": audio.basic.view,
+        "ogg": audio.basic.view,
+        "opus": audio.basic.view,
+        "wav": audio.basic.view,
+        "webm": audio.basic.view,
+    },
+    "video": {"mp4": video.mp4.view},
+    "image": {
+        "jpeg": image.basic.view,
+        "png": image.basic.view,
+        "avif": image.basic.view,
+    },
+}
+
+extensions = {"mp4": video.mp4.view, "mp3": audio.basic.view, "avif": image.basic.view}
diff --git a/akarpov/files/previews/audio/__init__.py b/akarpov/files/previews/audio/__init__.py
new file mode 100644
index 0000000..21123fd
--- /dev/null
+++ b/akarpov/files/previews/audio/__init__.py
@@ -0,0 +1 @@
+from . import basic  # noqa
diff --git a/akarpov/files/previews/audio/basic.py b/akarpov/files/previews/audio/basic.py
new file mode 100644
index 0000000..4b26ac0
--- /dev/null
+++ b/akarpov/files/previews/audio/basic.py
@@ -0,0 +1,61 @@
+from akarpov.files.models import File
+
+
+def view(file: File) -> (str, str):
+    static = """
+    """
+    content = (
+        """
+    <div id="waveform">
+    </div>
+    <div id="wave-timeline"> </div>
+
+    <div class="controls mt-4 d-flex align-items-center justify-content-center text-center">
+        <button class="btn btn-primary" data-action="play">
+            <i class="glyphicon glyphicon-play"></i>
+            Play
+            /
+            <i class="glyphicon glyphicon-pause"></i>
+            Pause
+        </button>
+    </div>
+    <script src="https://unpkg.com/wavesurfer.js@6.6.3/dist/wavesurfer.js"></script>
+    <script src="https://unpkg.com/wavesurfer.js@6.6.3/dist/plugin/wavesurfer.timeline.min.js"></script>
+    <script src="https://unpkg.com/wavesurfer.js@6.6.3/dist/plugin/wavesurfer.regions.min.js"></script>
+    <script>
+    window.onload = function() {
+    wavesurfer = WaveSurfer.create({
+        container: document.querySelector('#waveform'),
+        waveColor: '#D9DCFF',
+        progressColor: '#4353FF',
+        cursorColor: '#4353FF',
+        barWidth: 3,
+        barRadius: 3,
+        cursorWidth: 1,
+        height: 200,
+        barGap: 3,
+        plugins: [
+            WaveSurfer.regions.create({}),
+            WaveSurfer.timeline.create({
+                container: "#wave-timeline"
+            })
+        ]
+    });
+
+    wavesurfer.on('error', function(e) {
+        console.warn(e);
+    });
+    """
+        + f"""
+    wavesurfer.load('{file.file.url}');
+    """
+        + """
+    document
+        .querySelector('[data-action="play"]')
+        .addEventListener('click', wavesurfer.playPause.bind(wavesurfer));
+    }
+    </script>
+    """
+    )
+
+    return static, content
diff --git a/akarpov/files/previews/audio/waves.py b/akarpov/files/previews/audio/waves.py
new file mode 100644
index 0000000..a079633
--- /dev/null
+++ b/akarpov/files/previews/audio/waves.py
@@ -0,0 +1,102 @@
+from akarpov.files.models import File
+
+
+def view(file: File) -> (str, str):
+    static = """
+    <style>
+    #canvas {
+    position: absolute;
+    top: 0;
+    left: 0;
+    width: 100%;
+    height: 100%;
+    }
+    </style>
+    """
+    content = (
+        """
+    <div id="container">
+      <canvas id="canvas"></canvas>
+      <audio id="audio"></audio>
+    </div>
+    """
+        + """
+    <script>
+    const container = document.getElementById("container");
+    container.addEventListener("click", function () {
+      let audio1 = new Audio();
+      """
+        + f"""
+      audio1.src = "{file.file.url}";
+      """
+        + """
+      audio1.crossOrigin = "anonymous";
+      const audioCtx = new (window.AudioContext || window.webkitAudioContext)(); // for safari browser
+
+      const container = document.getElementById("container");
+      const canvas = document.getElementById("canvas");
+      canvas.width = window.innerWidth;
+      canvas.height = window.innerHeight;
+
+      const ctx = canvas.getContext("2d");
+
+      let audioSource = null;
+      let analyser = null;
+
+      audio1.play();
+      audioSource = audioCtx.createMediaElementSource(audio1);
+      analyser = audioCtx.createAnalyser();
+      audioSource.connect(analyser);
+      analyser.connect(audioCtx.destination);
+      analyser.fftSize = 128;
+      const bufferLength = analyser.frequencyBinCount;
+      const dataArray = new Uint8Array(bufferLength);
+
+      const barWidth = canvas.width / 2 / bufferLength;
+
+      let x = 0;
+
+      function animate() {
+        x = 0;
+        ctx.clearRect(0, 0, canvas.width, canvas.height); // clears the canvas
+        analyser.getByteFrequencyData(dataArray);
+        drawVisualizer({ bufferLength, dataArray, barWidth });
+        requestAnimationFrame(animate); // calls the animate function again. This method is built in
+      }
+
+      const drawVisualizer = ({ bufferLength, dataArray, barWidth }) => {
+        let barHeight;
+        for (let i = 0; i < bufferLength; i++) {
+          barHeight = dataArray[i];
+          const red = (i * barHeight) / 10;
+          const green = i * 4;
+          const blue = barHeight / 4 - 12;
+          ctx.fillStyle = `rgb(${red}, ${green}, ${blue})`;
+          ctx.fillRect(
+            canvas.width / 2 - x, // this will start the bars at the center of the canvas and move from right to left
+            canvas.height - barHeight,
+            barWidth,
+            barHeight
+          );
+          x += barWidth; // increases the x value by the width of the bar
+        }
+
+        for (let i = 0; i < bufferLength; i++) {
+          barHeight = dataArray[i];
+          const red = (i * barHeight) / 10;
+          const green = i * 4;
+          const blue = barHeight / 4 - 12;
+          ctx.fillStyle = `rgb(${red}, ${green}, ${blue})`;
+          ctx.fillRect(x, canvas.height - barHeight, barWidth, barHeight);
+          x += barWidth; // increases the x value by the width of the bar
+        }
+      };
+
+      animate();
+    });
+
+    </script>
+    """
+    )
+
+    return static, content
diff --git a/akarpov/files/previews/image/__init__.py b/akarpov/files/previews/image/__init__.py
index ae2d45a..21123fd 100644
--- a/akarpov/files/previews/image/__init__.py
+++ b/akarpov/files/previews/image/__init__.py
@@ -1 +1 @@
-from . import jpeg  # noqa
+from . import basic  # noqa
diff --git a/akarpov/files/previews/image/jpeg.py b/akarpov/files/previews/image/basic.py
similarity index 89%
rename from akarpov/files/previews/image/jpeg.py
rename to akarpov/files/previews/image/basic.py
index bb7aa50..c3302b0 100644
--- a/akarpov/files/previews/image/jpeg.py
+++ b/akarpov/files/previews/image/basic.py
@@ -10,6 +10,8 @@ def view(file: File) -> (str, str):
         <div>
           <img id="image" class="img-fluid" src="{file.file.url}" alt="Picture">
         </div>
+        <div id="images">
+        </div
       <script src="/static/js/jquery.js"></script>
     """
         + """
@@ -23,10 +25,7 @@ def view(file: File) -> (str, str):
               }
             });
 
-            // Get the Viewer.js instance after initialized
             var viewer = $image.data('viewer');
-
-            // View a list of images
             $('#images').viewer();
       </script>
     """
diff --git a/akarpov/files/previews/video/mp4.py b/akarpov/files/previews/video/mp4.py
index 93864ee..1ab30fa 100644
--- a/akarpov/files/previews/video/mp4.py
+++ b/akarpov/files/previews/video/mp4.py
@@ -9,7 +9,7 @@ def view(file: File) -> (str, str):
     content = f"""
 
       <video id="my_video_1" class="video-js vjs-default-skin" height="500px"
-          controls poster='{file.preview.url}'
+          controls poster='{file.preview.url if file.preview else ''}'
           data-setup='{data}'>
         <source src="{file.file.url}" type='video/mp4' />
       </video>
diff --git a/akarpov/files/views.py b/akarpov/files/views.py
index 973ea99..3f9b183 100644
--- a/akarpov/files/views.py
+++ b/akarpov/files/views.py
@@ -11,7 +11,7 @@
     ChunkedUploadView,
 )
 from akarpov.files.models import File, Folder
-from akarpov.files.previews import previews
+from akarpov.files.previews import extensions, previews
 
 
 class TopFolderView(LoginRequiredMixin, ListView):
@@ -41,10 +41,15 @@ def get_context_data(self, **kwargs):
         static = ""
         content = ""
         if self.object.file_type:
-            t1, t2 = self.object.file_type.split("/")
-            if t1 in previews:
-                if t2 in previews[t1]:
-                    static, content = previews[t1][t2](self.object)
+            if self.object.file_type == "application/octet-stream":
+                extension = self.object.file.path.split(".")[-1]
+                if extension in extensions:
+                    static, content = extensions[extension](self.object)
+            else:
+                t1, t2 = self.object.file_type.split("/")
+                if t1 in previews:
+                    if t2 in previews[t1]:
+                        static, content = previews[t1][t2](self.object)
         context["preview_static"] = static
         context["preview_content"] = content
         return context
diff --git a/akarpov/templates/files/view.html b/akarpov/templates/files/view.html
index 3d8b2a2..a8d2ff6 100644
--- a/akarpov/templates/files/view.html
+++ b/akarpov/templates/files/view.html
@@ -8,7 +8,7 @@
 
 {% block content %}
 <div class="row m-2">
-  <div class="col-auto">
+  <div class="col-md-4 col-sm-6">
     <h1 class="fs-1">{{ file.name }}</h1>
     {% if not has_perm %}
         <p>Uploaded by: <a href="{% url 'users:detail' file.user.username %}">
@@ -24,7 +24,7 @@
     <p>{{ file.description }}</p>
     {% endif %}
   </div>
-  <div class="col-auto">
+  <div class="col-md-8 col-sm-10">
   {% autoescape off %}
   {{ preview_content }}
   {% endautoescape %}
diff --git a/compose/local/django/install_preview_dependencies b/compose/local/django/install_preview_dependencies
index 1f60066..5d74cba 100644
--- a/compose/local/django/install_preview_dependencies
+++ b/compose/local/django/install_preview_dependencies
@@ -7,4 +7,4 @@ dpkg -i draw.io-amd64-13.0.3.deb
 rm draw.io-amd64-13.0.3.deb
 apt-get purge -y --auto-remove -o APT:AutoRemove:RecommendsImportant=false && \
 rm -rf /var/lib/apt/lists/*
-preview --check-dependencies``
+preview --check-dependencies