From f5ed6ec89676191df87b3186e05068c02c3b12cb Mon Sep 17 00:00:00 2001
From: Ben Visness <bvisness@gmail.com>
Date: Mon, 6 Dec 2021 23:20:12 -0600
Subject: [PATCH] Add live markdown preview to the description editor

---
 src/db/query_builder.go                       |   6 +-
 src/hmnurl/hmnurl_test.go                     |   6 +-
 src/hmnurl/urls.go                            |   6 +-
 src/templates/src/editor.html                 | 120 +++---------------
 src/templates/src/include/header.html         |   6 +-
 .../src/include/markdown_previews.html        | 106 ++++++++++++++++
 .../{editorpreviews.js => markdown_worker.js} |  23 ++--
 src/templates/src/project_edit.html           |  70 +++++++---
 src/website/projects.go                       |  30 +++--
 src/website/routes.go                         |   4 +-
 10 files changed, 221 insertions(+), 156 deletions(-)
 create mode 100644 src/templates/src/include/markdown_previews.html
 rename src/templates/src/{editorpreviews.js => markdown_worker.js} (60%)

diff --git a/src/db/query_builder.go b/src/db/query_builder.go
index 1f794c9..80a687f 100644
--- a/src/db/query_builder.go
+++ b/src/db/query_builder.go
@@ -14,9 +14,9 @@ type QueryBuilder struct {
 Adds the given SQL and arguments to the query. Any occurrences
 of `$?` will be replaced with the correct argument number.
 
-foo $? bar $? baz $?
-foo ARG1 bar ARG2 baz $?
-foo ARG1 bar ARG2 baz ARG3
+	foo $? bar $? baz $?
+	foo ARG1 bar ARG2 baz $?
+	foo ARG1 bar ARG2 baz ARG3
 */
 func (qb *QueryBuilder) Add(sql string, args ...interface{}) {
 	numPlaceholders := strings.Count(sql, "$?")
diff --git a/src/hmnurl/hmnurl_test.go b/src/hmnurl/hmnurl_test.go
index 2832c92..77dba56 100644
--- a/src/hmnurl/hmnurl_test.go
+++ b/src/hmnurl/hmnurl_test.go
@@ -298,12 +298,12 @@ func TestProjectCSS(t *testing.T) {
 	AssertRegexMatch(t, BuildProjectCSS("000000"), RegexProjectCSS, nil)
 }
 
-func TestEditorPreviewsJS(t *testing.T) {
-	AssertRegexMatch(t, BuildEditorPreviewsJS(), RegexEditorPreviewsJS, nil)
+func TestMarkdownWorkerJS(t *testing.T) {
+	AssertRegexMatch(t, BuildMarkdownWorkerJS(), RegexMarkdownWorkerJS, nil)
 }
 
 func TestAPICheckUsername(t *testing.T) {
-	AssertRegexmatch(t, BuildAPICheckUsername(), RegexAPICheckUsername, nil)
+	AssertRegexMatch(t, BuildAPICheckUsername(), RegexAPICheckUsername, nil)
 }
 
 func TestPublic(t *testing.T) {
diff --git a/src/hmnurl/urls.go b/src/hmnurl/urls.go
index dfb8cc9..4e8e8ba 100644
--- a/src/hmnurl/urls.go
+++ b/src/hmnurl/urls.go
@@ -702,11 +702,11 @@ func BuildProjectCSS(color string) string {
 	return Url("/assets/project.css", []Q{{"color", color}})
 }
 
-var RegexEditorPreviewsJS = regexp.MustCompile("^/assets/editorpreviews.js$")
+var RegexMarkdownWorkerJS = regexp.MustCompile("^/assets/markdown_worker.js$")
 
-func BuildEditorPreviewsJS() string {
+func BuildMarkdownWorkerJS() string {
 	defer CatchPanic()
-	return Url("/assets/editorpreviews.js", nil)
+	return Url("/assets/markdown_worker.js", nil)
 }
 
 var RegexS3Asset *regexp.Regexp
diff --git a/src/templates/src/editor.html b/src/templates/src/editor.html
index 6bf5937..580f6d9 100644
--- a/src/templates/src/editor.html
+++ b/src/templates/src/editor.html
@@ -1,11 +1,9 @@
 {{ template "base.html" . }}
 
 {{ define "extrahead" }}
-    <script src="{{ static "go_wasm_exec.js" }}"></script>
+    {{ template "markdown_previews.html" . }}
+
     <script src="{{ static "js/base64.js" }}"></script>
-    <script>
-        const previewWorker = new Worker('/assets/editorpreviews.js');
-    </script>
 
     <style>
         #editor {
@@ -73,15 +71,6 @@
                     <input name="editreason" maxlength="255" type="text" id="editreason" />
                 </span>
             {{ end }}
-            
-            {{/* TODO: Sticky threads
-            {% if user.is_staff and post and post.depth == 0 %}
-                <div class="checkbox sticky">
-                    <input type="checkbox" name="sticky" id="sticky" {% if thread.sticky %}checked{% endif%} />
-                    <label for="sticky">Sticky thread</label>
-                </div>
-            {% endif %}
-            */}}
 
             {{ with .PostReplyingTo }}
                 <h4 class="mt3">The post you're replying to:</h4>
@@ -89,27 +78,6 @@
                     {{ template "forum_post_standalone.html" . }}
                 </div>
             {{ end }}
-
-            {{/*
-
-            {% if context_newer %}
-                <h4>Replies since then:</h4>
-                <div class="recent-posts">
-                    {% for post in posts_newer %}
-                        {% include "forum_thread_single_post.html" %}
-                    {% endfor %}
-                </div>
-            {% endif %}
-
-            {% if context_older %}
-                <h4>Replies before then:</h4>
-                <div class="recent-posts">
-                    {% for post in posts_older %}
-                        {% include "forum_thread_single_post.html" %}
-                    {% endfor %}
-                </div>
-            {% endif %}
-            */}}
         </form>
         <div id="preview-container" class="post post-preview mathjax flex-fair-ns overflow-auto mv3 mv0-ns ml3-ns pa3 br3 bg--dim">
             <div id="preview" class="post-content"></div>
@@ -127,74 +95,28 @@
     const textField = document.querySelector('#editor');
     const preview = document.querySelector('#preview');
 
-    const storagePrefix = 'post-contents';
-
-    // Delete old irrelevant local post contents
-    const aWeekAgo = new Date().getTime() - (7 * 24 * 60 * 60 * 1000);
-    for (const key in window.localStorage) {
-        if (!window.localStorage.hasOwnProperty(key)) {
-            continue;
-        }
-
-        if (key.startsWith(storagePrefix)) {
-            try {
-                const { when } = JSON.parse(window.localStorage.getItem(key));
-                if (when <= aWeekAgo) {
-                    window.localStorage.removeItem(key);
-                }
-            } catch (e) {
-                console.error(e);
-            }
-        }
-    }
-
-    // Load any stored content from localStorage
-    const storageKey = `${storagePrefix}/${window.location.host}${window.location.pathname}`;
-    const storedContents = window.localStorage.getItem(storageKey);
-    if (storedContents && !textField.value) {
-        try {
-            const { title, contents } = JSON.parse(storedContents);
-            if (titleField) {
-                titleField.value = title;
-            }
-            textField.value = contents;
-        } catch (e) {
-            console.error(e);
-        }
-    }
-
-    function updatePreview(previewHtml) {
-        preview.innerHTML = previewHtml;
-        MathJax.typeset();
-    }
-
-    previewWorker.onmessage = ({ data }) => {
-        updatePreview(data);
-    };
-
-    function doMarkdown() {
-        const md = textField.value;
-        previewWorker.postMessage(md);
-        updateContentCache();
-    }
-
-    function updateContentCache() {
-        window.localStorage.setItem(storageKey, JSON.stringify({
-            when: new Date().getTime(),
-            title: titleField ? titleField.value : '',
-            contents: textField.value,
-        }));
-    }
-
-    doMarkdown();
-    textField.addEventListener('input', () => doMarkdown());
+    // Save content on change, clear on submit
+    const clearFuncs = [];
     if (titleField) {
-        titleField.addEventListener('input', () => updateContentCache());
+        const { clear: clearTitle } = autosaveContent({
+            inputEl: titleField,
+            storageKey: `post-title/${window.location.host}${window.location.pathname}`,
+        });
+        clearFuncs.push(clearTitle);
     }
-
-    form.addEventListener('submit', e => {
-        window.localStorage.removeItem(storageKey);
+    const { clear: clearContent } = autosaveContent({
+        inputEl: textField,
+        storageKey: `post-content/${window.location.host}${window.location.pathname}`,
     });
+    clearFuncs.push(clearContent);
+    form.addEventListener('submit', e => {
+        for (const clear of clearFuncs) {
+            clear();
+        }
+    });
+
+    // Do live Markdown previews
+    initLiveMarkdown({ inputEl: textField, previewEl: preview });
 
     /*
     / Asset upload
diff --git a/src/templates/src/include/header.html b/src/templates/src/include/header.html
index 6d59df4..b124340 100644
--- a/src/templates/src/include/header.html
+++ b/src/templates/src/include/header.html
@@ -54,7 +54,7 @@
                             </div>
                         {{ end }}
 						{{ if .CanEdit }}
-							<div class="flex-grow-1"></div>
+							<div class="flex-grow-1 dn db-ns"></div>
 							<div class="root-item flex-shrink-0">
 								<a href="{{ .EditUrl }}">Edit Project</a>
 							</div>
@@ -89,8 +89,8 @@
             {{ end }}
         </div>
         <div class="dn flex-ns items-center f3">
-            <a class="svgicon" href="https://twitter.com/handmade_net/" target="_blank">{{ svg "twitter" }}</a>
-            <a class="svgicon ml2" href="https://discord.gg/hxWxDee" target="_blank">{{ svg "discord" }}</a>
+            <a class="svgicon svgicon-nofix" href="https://twitter.com/handmade_net/" target="_blank">{{ svg "twitter" }}</a>
+            <a class="svgicon svgicon-nofix ml2" href="https://discord.gg/hxWxDee" target="_blank">{{ svg "discord" }}</a>
         </div>
     </div>
 </header>
diff --git a/src/templates/src/include/markdown_previews.html b/src/templates/src/include/markdown_previews.html
new file mode 100644
index 0000000..9d442a7
--- /dev/null
+++ b/src/templates/src/include/markdown_previews.html
@@ -0,0 +1,106 @@
+<script src="{{ static "go_wasm_exec.js" }}"></script>
+<script>
+    const previewWorker = new Worker('/assets/markdown_worker.js');
+
+    /*
+    Automatically save and restore content from a text field on change.
+
+    Return type:
+
+        {
+            // Call this function when you submit the form or otherwise want
+            // to delete the work-in-progress user content.
+            clearStorage: () => {},
+        }
+
+    */
+    function autosaveContent({
+        // HTML input or textarea
+        inputEl,
+        // Unique string identifying this field across the site.
+        storageKey,
+    }) {
+        const storagePrefix = 'saved-content';
+
+        // Delete old irrelevant local contents
+        const aWeekAgo = new Date().getTime() - (7 * 24 * 60 * 60 * 1000);
+        for (const key in window.localStorage) {
+            if (!window.localStorage.hasOwnProperty(key)) {
+                continue;
+            }
+
+            if (key.startsWith(storagePrefix)) {
+                try {
+                    const { when } = JSON.parse(window.localStorage.getItem(key));
+                    if (when <= aWeekAgo) {
+                        window.localStorage.removeItem(key);
+                    }
+                } catch (e) {
+                    console.error(e);
+                }
+            }
+        }
+
+        // Load any stored content from localStorage
+        const storageKeyFull = `${storagePrefix}/${storageKey}`;
+        const storedContents = window.localStorage.getItem(storageKeyFull);
+        if (storedContents && !inputEl.value) {
+            try {
+                const { contents } = JSON.parse(storedContents);
+                inputEl.value = contents;
+            } catch (e) {
+                console.error(e);
+            }
+        }
+
+        function updateContentCache() {
+            window.localStorage.setItem(storageKeyFull, JSON.stringify({
+                when: new Date().getTime(),
+                contents: inputEl.value,
+            }));
+        }
+
+        inputEl.addEventListener('input', () => updateContentCache());
+
+        return {
+            clear() {
+                window.localStorage.removeItem(storageKeyFull);
+            },
+        }
+    }
+
+    const markdownIds = [];
+
+    /*
+    Initialize live Markdown rendering.
+    */
+    function initLiveMarkdown({
+        // HTML input or textarea
+        inputEl,
+        // HTML element in which to render markdown
+        previewEl,
+    }) {
+        if (markdownIds.includes(inputEl.id)) {
+            console.warn(`Multiple elements with ID "${inputEl.id}" are being used for Markdown. Results will be very confusing!`);
+        }
+        markdownIds.push(inputEl.id);
+
+        previewWorker.onmessage = ({ data }) => {
+            const { elementID, html } = data;
+            if (elementID === inputEl.id) {
+                previewEl.innerHTML = html;
+                MathJax.typeset();
+            }
+        };
+
+        function doMarkdown() {
+            previewWorker.postMessage({
+                elementID: inputEl.id,
+                markdown: inputEl.value,
+            });
+        }
+
+        doMarkdown();
+        inputEl.addEventListener('input', () => doMarkdown());
+    }
+</script>
diff --git a/src/templates/src/editorpreviews.js b/src/templates/src/markdown_worker.js
similarity index 60%
rename from src/templates/src/editorpreviews.js
rename to src/templates/src/markdown_worker.js
index 8ed71dc..c602abc 100644
--- a/src/templates/src/editorpreviews.js
+++ b/src/templates/src/markdown_worker.js
@@ -5,11 +5,12 @@ NOTE(ben): The structure here is a little funny but allows for some debouncing.
 that got queued up can run all at once, then it can process the latest one.
  */
 
-let ready = false;
-let inputData = null;
+let wasmLoaded = false;
+let jobs = {};
 
 onmessage = ({ data }) => {
-    inputData = data;
+    const { elementID, markdown } = data;
+    jobs[elementID] = markdown;
     setTimeout(doPreview, 0);
 }
 
@@ -17,17 +18,21 @@ const go = new Go();
 WebAssembly.instantiateStreaming(fetch('/public/parsing.wasm'), go.importObject)
     .then(result => {
         go.run(result.instance); // don't await this; we want it to be continuously running
-        ready = true;
+        wasmLoaded = true;
         setTimeout(doPreview, 0);
     });
 
 const doPreview = () => {
-    if (!ready || inputData === null) {
+    if (!wasmLoaded) {
         return;
     }
 
-    const result = parseMarkdown(inputData);
-    inputData = null;
-
-    postMessage(result);
+    for (const [elementID, markdown] of Object.entries(jobs)) {
+        const html = parseMarkdown(markdown);
+        postMessage({
+            elementID: elementID,
+            html: html,
+        });
+    }
+    jobs = {};
 }
diff --git a/src/templates/src/project_edit.html b/src/templates/src/project_edit.html
index ca208f9..522ec6d 100644
--- a/src/templates/src/project_edit.html
+++ b/src/templates/src/project_edit.html
@@ -1,13 +1,22 @@
 {{ template "base.html" . }}
 
 {{ define "extrahead" }}
+	{{ template "markdown_previews.html" . }}
 	<script src="{{ static "js/tabs.js" }}"></script>
 	<script src="{{ static "js/image_selector.js" }}"></script>
 	<script src="{{ static "js/templates.js" }}"></script>
+	
+	<style>
+		#desc-preview:empty::after {
+			content: 'A preview of your description will appear here.';
+			color: var(--dimmer-color);
+			font-style: italic;
+		}
+	</style>
 {{ end }}
 
 {{ define "content" }}
-	<div class="content-block">
+	<div class="ph3 ph0-ns">
 		{{ if .Editing }}
 			<h1>Edit {{ .ProjectSettings.Name }}</h1>
 		{{ else }}
@@ -28,20 +37,12 @@
 					<div>
 						<select name="lifecycle">
 							<option value="active" {{ if eq .ProjectSettings.Lifecycle "active" }}selected{{ end }}>Active</option>
-							<option value="hiatus" {{ if eq .ProjectSettings.Lifecycle "hiatus" }}selected{{ end }}>Hiatus</option>
+							<option value="hiatus" {{ if eq .ProjectSettings.Lifecycle "hiatus" }}selected{{ end }}>On Hiatus</option>
 							<option value="done"   {{ if eq .ProjectSettings.Lifecycle "done"   }}selected{{ end }}>Completed</option>
 							<option value="dead"   {{ if eq .ProjectSettings.Lifecycle "dead"   }}selected{{ end }}>Abandoned</option>
 						</select>
 					</div>
 				</div>
-				<div class="edit-form-row">
-					{{/* TODO(asaf): Should this be admin only??*/}}
-					<div>Hidden:</div>
-					<div>
-						<input id="hidden" type="checkbox" name="hidden" {{ if .ProjectSettings.Hidden }}checked{{ end }} />
-						<label for="hidden">Hide</label>
-					</div>
-				</div>
 				<div class="edit-form-row">
 					<div class="pt-input-ns">Owners:</div>
 					<div>
@@ -72,12 +73,6 @@
 					<div class="edit-form-row">
 						<div class="pt-input-ns">Admin settings</div>
 					</div>
-					<div class="edit-form-row">
-						<div class="pt-input-ns">Slug:</div>
-						<div>
-							<input type="text" name="slug" maxlength="255" class="textbox" value="{{ .ProjectSettings.Slug }}">
-						</div>
-					</div>
 					<div class="edit-form-row">
 						<div>Official:</div>
 						<div>
@@ -85,12 +80,27 @@
 							<label for="official">Official HMN project</label>
 						</div>
 					</div>
+					<div class="edit-form-row">
+						<div>Hidden:</div>
+						<div>
+							<input id="hidden" type="checkbox" name="hidden" {{ if .ProjectSettings.Hidden }}checked{{ end }} />
+							<label for="hidden">Hide</label>
+						</div>
+					</div>
+					<div class="edit-form-row">
+						<div class="pt-input-ns">Slug:</div>
+						<div>
+							<input type="text" name="slug" maxlength="255" class="textbox" value="{{ .ProjectSettings.Slug }}">
+							<div class="c--dim f7">Has no effect for personal projects. Personal projects have a slug derived from the title.</div>
+							<div class="c--dim f7">If you change this, make sure to change DNS too!</div>
+						</div>
+					</div>
 					<div class="edit-form-row">
 						<div>Featured:</div>
 						<div>
 							<input id="featured" type="checkbox" name="featured" {{ if .ProjectSettings.Featured }}checked{{ end }} />
 							<label for="featured">Featured</label>
-							<div class="c--dim f7">Bump to the top of the project index and show in the carousel.</div>
+							<div class="c--dim f7">Bump to the top of the project index and show in the carousel. Has no effect for personal projects.</div>
 						</div>
 					</div>
 				{{ end }}
@@ -118,10 +128,11 @@
 				<div class="edit-form-row">
 					<div class="pt-input-ns">Full description:</div>
 					<div>
-						<textarea class="w-100 h6 minh-6 mono lh-copy" name="description">
+						<textarea id="description" class="w-100 h5 minh-5 mono lh-copy" name="description">
 							{{- .ProjectSettings.Description -}}
 						</textarea>
-						{{/* TODO(asaf): Replace with the full editor */}}
+						<div class="b mt3 mb2">Preview:</div>
+						<div id="desc-preview" class="w-100"></div>
 					</div>
 				</div>
 				<div class="edit-form-row">
@@ -164,7 +175,7 @@
 	<script>
 	let csrf = JSON.parse({{ csrftokenjs .Session }});
 
-	let projectForm = document.querySelector("#project_form")
+	let projectForm = document.querySelector("#project_form");
 
 	projectForm.addEventListener("invalid", function(ev) {
 		switchToTabOfElement(document.body, ev.target);
@@ -174,6 +185,25 @@
 		switchTab(document.body, tabName);
 	}
 
+	////////////////////////////
+	// Description management //
+	////////////////////////////
+
+	{{ if .Editing }}
+		const projectName = "new-project";
+	{{ else }}
+		const projectName = "{{ .Project.Name }}";
+	{{ end }}
+	const description = document.querySelector('#description');
+	const descPreview = document.querySelector('#desc-preview');
+	const { clear: clearDescription } = autosaveContent({
+		inputEl: description,
+		storageKey: `project-description/${projectName}`,
+	});
+	projectForm.addEventListener('submit', () => clearDescription());
+
+	initLiveMarkdown({ inputEl: description, previewEl: descPreview });
+
 	//////////////////////
 	// Owner management //
 	//////////////////////
diff --git a/src/website/projects.go b/src/website/projects.go
index 490da4c..8835ee5 100644
--- a/src/website/projects.go
+++ b/src/website/projects.go
@@ -432,7 +432,7 @@ func ProjectNewSubmit(c *RequestContext) ResponseData {
 
 	formResult.Payload.ProjectID = projectId
 
-	err = UpdateProject(c.Context(), tx, c.CurrentUser, &formResult.Payload)
+	err = updateProject(c.Context(), tx, c.CurrentUser, &formResult.Payload)
 	if err != nil {
 		return c.ErrorResponse(http.StatusInternalServerError, err)
 	}
@@ -492,7 +492,7 @@ func ProjectEditSubmit(c *RequestContext) ResponseData {
 
 	formResult.Payload.ProjectID = c.CurrentProject.ID
 
-	err = UpdateProject(c.Context(), tx, c.CurrentUser, &formResult.Payload)
+	err = updateProject(c.Context(), tx, c.CurrentUser, &formResult.Payload)
 	if err != nil {
 		return c.ErrorResponse(http.StatusInternalServerError, err)
 	}
@@ -609,7 +609,7 @@ func ParseProjectEditForm(c *RequestContext) ProjectEditFormResult {
 	return res
 }
 
-func UpdateProject(ctx context.Context, conn db.ConnOrTx, user *models.User, payload *ProjectPayload) error {
+func updateProject(ctx context.Context, conn db.ConnOrTx, user *models.User, payload *ProjectPayload) error {
 	var lightLogoUUID *uuid.UUID
 	if payload.LightLogo.Exists {
 		lightLogo := &payload.LightLogo
@@ -657,26 +657,28 @@ func UpdateProject(ctx context.Context, conn db.ConnOrTx, user *models.User, pay
 		payload.OwnerUsernames = append(payload.OwnerUsernames, selfUsername)
 	}
 
-	_, err := conn.Exec(ctx,
+	var qb db.QueryBuilder
+	qb.Add(
 		`
 		UPDATE handmade_project SET
-			name = $2,
-			blurb = $3,
-			description = $4,
-			descparsed = $5,
-			lifecycle = $6,
-			hidden = $7
-		WHERE
-			id = $1
+			name = $?,
+			blurb = $?,
+			description = $?,
+			descparsed = $?,
+			lifecycle = $?,
 		`,
-		payload.ProjectID,
 		payload.Name,
 		payload.Blurb,
 		payload.Description,
 		payload.ParsedDescription,
 		payload.Lifecycle,
-		payload.Hidden,
 	)
+	if user.IsStaff {
+		qb.Add(`hidden = $?`, payload.Hidden)
+	}
+	qb.Add(`WHERE id = $?`, payload.ProjectID)
+
+	_, err := conn.Exec(ctx, qb.String(), qb.Args()...)
 	if err != nil {
 		return oops.New(err, "Failed to update project")
 	}
diff --git a/src/website/routes.go b/src/website/routes.go
index c35148d..db7fc84 100644
--- a/src/website/routes.go
+++ b/src/website/routes.go
@@ -350,9 +350,9 @@ func NewWebsiteRoutes(longRequestContext context.Context, conn *pgxpool.Pool) ht
 	anyProject.GET(hmnurl.RegexCineraIndex, CineraIndex)
 
 	anyProject.GET(hmnurl.RegexProjectCSS, ProjectCSS)
-	anyProject.GET(hmnurl.RegexEditorPreviewsJS, func(c *RequestContext) ResponseData {
+	anyProject.GET(hmnurl.RegexMarkdownWorkerJS, func(c *RequestContext) ResponseData {
 		var res ResponseData
-		res.MustWriteTemplate("editorpreviews.js", nil, c.Perf)
+		res.MustWriteTemplate("markdown_worker.js", nil, c.Perf)
 		res.Header().Add("Content-Type", "application/javascript")
 		return res
 	})