From b2fa05060d4b31ad71c7a704cb1ead17229cbee8 Mon Sep 17 00:00:00 2001
From: projectmoon <projectmoon@agnos.is>
Date: Fri, 6 Jan 2023 16:51:35 +0100
Subject: [PATCH] Implement support for browser history API.

---
 src/index.html   |  4 +--
 src/ts/index.tsx | 71 +++++++++++++++++++++++++++++++++++++++++-------
 2 files changed, 63 insertions(+), 12 deletions(-)

diff --git a/src/index.html b/src/index.html
index 75d5d68..2a65d8c 100644
--- a/src/index.html
+++ b/src/index.html
@@ -25,7 +25,7 @@
             <div id="real-body" class="d-none">
                 <nav id="main-navbar" class="navbar px-0 sticky-top navbar-expand-lg bg-light">
                     <div class="container-fluid">
-                        <a class="navbar-brand" href="#">
+                        <a class="navbar-brand" href="javascript:void(0);">
                             🔥 MSN Viewer
                         </a>
                         <button class="navbar-toggler" type="button"
@@ -64,7 +64,7 @@
                             </button>
                             <ul class="dropdown-menu">
                                 <li>
-                                    <a id="loaded-load-previous-button" class="dropdown-item disabled" href="#">
+                                    <a id="loaded-load-previous-button" class="dropdown-item disabled" href="javascript:void(0);">
                                         <i class="text-start bi bi-files"></i> Load Previous
                                     </a>
                                 </li>
diff --git a/src/ts/index.tsx b/src/ts/index.tsx
index b1bef6a..fd370d4 100644
--- a/src/ts/index.tsx
+++ b/src/ts/index.tsx
@@ -28,6 +28,12 @@ function showLoadedControls() {
     ui.fileLoadedControls.classList.remove('d-none');
 }
 
+function showNotLoadedControls() {
+    ui.noFileLoadedControls.classList.remove('d-none');
+    ui.noFileLoadedControls.classList.add('d-lg-block');
+    ui.fileLoadedControls.classList.add('d-none');
+}
+
 function displayError(errorDiv: HTMLElement, category: string, ex: Error) {
     console.error(ex);
     const errorHeading = errorDiv.querySelector('.alert-heading') as HTMLElement | null;
@@ -121,6 +127,11 @@ function displayBackup(xsltProcessor: XSLTProcessor, filename: string, xmlText:
             ui.chatDisplay.appendChild(fragment);
             ui.currentlyViewing.value = filename;
             processFragment();
+            if (history.state?.filename != filename) {
+                history.pushState({ filename }, '', `#!/${filename}`);
+            }
+
+            document.title = `MSN Viewer - ${filename}`;
             return true;
         }
         catch (e) {
@@ -183,7 +194,27 @@ async function initEvents() {
         }
     });
 
-    // ui.previousBackupsList.addEventListener('click', , true);
+    window.onpopstate = async (event) => {
+        const filename = event?.state?.filename as string | null;
+
+        if (filename) {
+            await doLoadBackup(event.state.filename);
+        } else {
+            reset();
+        }
+    }
+}
+
+function reset() {
+    //real body shown
+    //minibar hidden
+    //initial stuff shown
+    showApplication(true);
+    showNotLoadedControls();
+    hideErrors();
+    removeChildren(ui.chatDisplay);
+    history.replaceState(null, 'MSN Viewer', '');
+    document.title = 'MSN Viewer';
 }
 
 async function deleteBackup(e: MouseEvent) {
@@ -208,25 +239,33 @@ async function deleteBackup(e: MouseEvent) {
     }
 }
 
+async function doLoadBackup(filename: string) {
+    const entry = await db.entries.get(filename);
+    if (entry) {
+        displayBackup(xsltProcessor, entry.filename, entry.backupData);
+    } else {
+        displayNonFatalError(
+            'Internal Error',
+            new Error(`Could not find data for backup: ${filename}`)
+        );
+    }
+
+    bootstrap.Modal.getInstance(ui.previousBackupsModal)?.hide();
+}
+
 async function loadBackup(e: MouseEvent) {
     const listItem = e.target as HTMLElement | null;
     const filename = listItem?.dataset['filename'];
 
     if (filename) {
-        const entry = await db.entries.get(filename);
-        if (entry) {
-            displayBackup(xsltProcessor, entry.filename, entry.backupData);
-        } else {
-            displayNonFatalError('Internal Error', new Error('Backup data disappeared?!'));
-        }
-
-        bootstrap.Modal.getInstance(ui.previousBackupsModal)?.hide();
+        await doLoadBackup(filename);
     }
 }
 
 function BackupListItem(props: { filename: string }) {
     return (
-        <a href="#" class="backup-entry list-group-item list-group-item-action"
+        <a href="javascript:void(0);"
+            class="backup-entry list-group-item list-group-item-action"
             onClick={loadBackup} dataset={{ filename: props.filename }}>
             <div class="backup-name pe-none">
                 {props.filename}
@@ -250,8 +289,20 @@ async function populateSavedBackups() {
     modal.show();
 }
 
+async function parseURL() {
+    if (window.location.hash && window.location.hash.startsWith('#!/')) {
+        const split = window.location.hash.split('#!/');
+        if (split.length > 1) {
+            const filename = split[1];
+            console.log(filename);
+            await doLoadBackup(filename);
+        }
+    }
+}
+
 window.addEventListener('DOMContentLoaded', async () => {
     await initEvents();
     showLoadingIndicator(false);
+    await parseURL();
     showApplication(true);
 });