Implementation

1 files changed, 188 insertions, 0 deletions

diff --git a/client/js/radio_emulator.js b/client/js/radio_emulator.js
new file mode 100644
index 0000000..98138e7
--- /dev/null
+++ b/client/js/radio_emulator.js
@@ -0,0 +1,188 @@
+// Radio Emulator
+// Kaotisk Hund 2024
+//
+// A simple co-mechanism to pretend playing a live radio as it would happen for
+// a radio station that mostly plays prerecoded shows.
+//
+// Client side implementation
+// Let's remind here the structures we are waiting for:
+// 1. Hash
+// 2. 0
+// 3. audio/ogg file
+// 4. application/json file
+//
+// 1. Hash
+// Can be an SHA512sum or SHA256sum, we don't do checks, we only ask the hash
+// accompanied by what do we think it is.
+//
+// 2. 0
+// When nothing exists on the radio station we are visiting.
+//
+// 3. audio/ogg file
+// An audio file to play.
+//
+// 4. application/json file
+// Could be one of the following:
+//   - list
+//   - show_info
+//
+
+var audioElement = document.querySelector('audio');
+var sourceElement = document.querySelector('source');
+var currentTimeP = document.querySelector('.current-time');
+var listStartedP = document.querySelector('.started-on');
+var currentShowHash = document.querySelector('.current-show-hash');
+var listHash = document.querySelector('.list-hash');
+var artistP = document.querySelector('.artist');
+var titleP = document.querySelector('.title');
+var radioPlayerDiv = document.querySelector('.radio-player');
+var youAreHere = document.querySelector('.you-are-here');
+
+var seconds_here = 0;
+function increaseSeconds()
+{
+    seconds_here = seconds_here+1;
+    youAreHere.innerText = seconds_here;
+    return seconds_here;
+}
+function getSecondsHere()
+{
+    return seconds_here;
+}
+
+setInterval(increaseSeconds, 1000);
+
+
+function FetchJSON( url, callback, params )
+{
+    const request = new XMLHttpRequest();
+    request.addEventListener("load", ()=>{
+        var json = JSON.parse(request.response);
+        if(request.status !== 404){
+            callback(json, params);
+        } else {
+            console.log(`ERROR ${request.status} while loading ${url}`);
+        }
+    });
+    request.addEventListener("error", ()=>{
+        console.log("An error occured. While loading: "+url+" for "+callback+".");
+    });
+    // ProgressBar update: Interesting but not needed
+    // request.addEventListener("progress", (event)=>{
+    //     if (event.lengthComputable && progressPlaceholder){
+    //         httpProgressPlaceholder.value = (event.loaded / event.total) * 100;
+    //     } else {
+    //         httpProgressPlaceholder.value = 0;
+    //         // console.log("Supposingly zeroed progressPlaceholder");
+    //     }
+    // });
+    request.addEventListener("abort", ()=>{
+        console.log("Request aborted.");
+    });
+    request.open("GET", url);
+    request.send();
+}
+
+function genericCallback(json, params)
+{
+    console.log('genericCallback');
+    console.log(json);
+    console.log(params);
+}
+
+var calledLoadShowCallback = 0;
+
+function stopHereAndReflect()
+{
+
+}
+
+function loadShowCallback(json, params)
+{
+    const [ list, now_on_sequence, element, hash_of_list ] = params;
+//    if ( calledLoadShowCallback === 0 )
+//    {
+//        calledLoadShowCallback++;
+        console.log('loadShowCallback');
+        console.log(json);
+        console.log(element);
+        console.log(params);
+        listStartedP.innerText = list.started_on;
+        listHash.innerText = hash_of_list;
+        currentShowHash.innerText = json.hash;
+        artistP.innerText = json.artist;
+        titleP.innerText = json.title;
+        // audioElement.pause();
+        sourceElement.src = "http://z.kaotisk-hund.com:8010/v0/audio/ogg/" + json.hash + "#t=" + Math.floor((now_on_sequence - element.starts_on)/1000);
+        sourceElement.type = json.mimetype;
+        audioElement.load();
+        console.log('plays here: '+(now_on_sequence - element.starts_on)/1000);
+        audioElement.addEventListener('canplaythrough', function(){
+            console.log('CAN PLAY THROUGH');
+            if ( calledLoadShowCallback < 100 )
+            {
+                calledLoadShowCallback++;
+                currentTimeP.innerText = ((now_on_sequence - element.starts_on)/1000);
+                audioElement.currentTime = ((now_on_sequence - element.starts_on)/1000);
+                audioElement.play();
+            }
+        });
+        audioElement.addEventListener('ended', function(){
+            location.reload();
+            //FetchJSON('http://z.kaotisk-hund.com:8010/v0/list', hashCallback, [ new Date().getTime()]);
+        });
+        sync_radio();
+        setTimeout(sync_radio, 30000);
+
+//    } else {
+//        return 0;
+//    }
+}
+
+function sync_radio()
+{
+    var value = currentTimeP.innerText;
+    var new_now = parseFloat(value) + getSecondsHere();
+    console.log("Trying to sync @ "+ value + " + " +getSecondsHere() + " = " + new_now);
+    if ( value !== "" )
+    {
+        audioElement.currentTime = new_now;
+    }
+}
+
+function listCallback(json, params)
+{
+    console.log('listCallback');
+    var [ now, hash_of_list ] = params;
+    // var now = Date.now();
+    var delta_time = now - json.started_on;
+    var min_times_played = Math.floor( delta_time / json.duration );
+    var max_times_to_be_played = delta_time / json.duration;
+    var Dt = max_times_to_be_played - min_times_played;
+    var now_on_sequence = Dt * json.duration;
+    console.log(`now_on_sequence: ${now_on_sequence}, Dt: ${Dt}`)
+
+    previous = { starts_on: 0 };
+    json.list.forEach((element)=>{
+        if ( now_on_sequence < element.starts_on && now_on_sequence > previous.starts_on){
+        } else {
+            now_on_sequence = now_on_sequence - previous.starts_on;
+            console.log(now_on_sequence);
+            previous = element;
+            console.log(element);
+            FetchJSON("http://z.kaotisk-hund.com:8010/v0/application/json/" + element.hash, loadShowCallback, [json, now_on_sequence, element, hash_of_list]);
+        }
+    });
+}
+
+function hashCallback(json, params)
+{
+    var [ now ] = params;
+    console.log('hashCallback');
+    FetchJSON('http://z.kaotisk-hund.com:8010/v0/application/json/' + json.latest_list, listCallback, [now, json.latest_list]);
+}
+
+FetchJSON('http://z.kaotisk-hund.com:8010/v0/list', hashCallback, [ new Date().getTime() ]);
+
+
+