wip(app): line selection

3 files changed, 130 insertions, 50 deletions

diff --git a/packages/app/src/components/prompt-input.tsx b/packages/app/src/components/prompt-input.tsx
index 0d6a7641a..5e936737a 100644
--- a/packages/app/src/components/prompt-input.tsx
+++ b/packages/app/src/components/prompt-input.tsx
@@ -164,6 +164,18 @@ export const PromptInput: Component<PromptInputProps> = (props) => {
     return files.pathFromTab(tab)
   })
 
+  const selectionPreview = (path: string, selection?: FileSelection, preview?: string) => {
+    if (preview) return preview
+    if (!selection) return undefined
+    const content = files.get(path)?.content?.content
+    if (!content) return undefined
+    const start = Math.max(1, Math.min(selection.startLine, selection.endLine))
+    const end = Math.max(selection.startLine, selection.endLine)
+    const lines = content.split("\n").slice(start - 1, end)
+    if (lines.length === 0) return undefined
+    return lines.slice(0, 2).join("\n")
+  }
+
   const activeFileSelection = createMemo(() => {
     const path = activeFile()
     if (!path) return
@@ -171,6 +183,11 @@ export const PromptInput: Component<PromptInputProps> = (props) => {
     if (!range) return
     return selectionFromLines(range)
   })
+  const activeSelectionPreview = createMemo(() => {
+    const path = activeFile()
+    if (!path) return
+    return selectionPreview(path, activeFileSelection())
+  })
   const info = createMemo(() => (params.id ? sync.session.get(params.id) : undefined))
   const status = createMemo(
     () =>
@@ -1485,40 +1502,49 @@ export const PromptInput: Component<PromptInputProps> = (props) => {
           </div>
         </Show>
         <Show when={prompt.context.items().length > 0 || !!activeFile()}>
-          <div class="flex flex-wrap items-center gap-1.5 px-3 pt-3">
+          <div class="flex flex-nowrap items-start gap-1.5 px-3 pt-3 overflow-x-auto no-scrollbar">
             <Show when={prompt.context.activeTab() ? activeFile() : undefined}>
               {(path) => (
-                <div class="flex items-center gap-1.5 px-1.5 py-0.5 rounded-md bg-surface-base border border-border-base max-w-full">
-                  <FileIcon node={{ path: path(), type: "file" }} class="shrink-0 size-3.5" />
-                  <div class="flex items-center text-11-regular min-w-0">
-                    <span class="text-text-weak whitespace-nowrap truncate min-w-0">{getDirectory(path())}</span>
-                    <span class="text-text-strong whitespace-nowrap">{getFilename(path())}</span>
-                    <Show when={activeFileSelection()}>
-                      {(sel) => (
-                        <span class="text-text-weak whitespace-nowrap ml-1">
-                          {sel().startLine === sel().endLine
-                            ? `:${sel().startLine}`
-                            : `:${sel().startLine}-${sel().endLine}`}
-                        </span>
-                      )}
-                    </Show>
-                    <span class="text-text-weak whitespace-nowrap ml-1">{language.t("prompt.context.active")}</span>
+                <div class="shrink-0 flex flex-col gap-1 rounded-md bg-surface-base border border-border-base px-2 py-1 max-w-[320px]">
+                  <div class="flex items-center gap-1.5">
+                    <FileIcon node={{ path: path(), type: "file" }} class="shrink-0 size-3.5" />
+                    <div class="flex items-center text-11-regular min-w-0">
+                      <span class="text-text-weak whitespace-nowrap truncate min-w-0">{getDirectory(path())}</span>
+                      <span class="text-text-strong whitespace-nowrap">{getFilename(path())}</span>
+                      <Show when={activeFileSelection()}>
+                        {(sel) => (
+                          <span class="text-text-weak whitespace-nowrap ml-1">
+                            {sel().startLine === sel().endLine
+                              ? `:${sel().startLine}`
+                              : `:${sel().startLine}-${sel().endLine}`}
+                          </span>
+                        )}
+                      </Show>
+                      <span class="text-text-weak whitespace-nowrap ml-1">{language.t("prompt.context.active")}</span>
+                    </div>
+                    <IconButton
+                      type="button"
+                      icon="close"
+                      variant="ghost"
+                      class="h-5 w-5"
+                      onClick={() => prompt.context.removeActive()}
+                      aria-label={language.t("prompt.context.removeActiveFile")}
+                    />
                   </div>
-                  <IconButton
-                    type="button"
-                    icon="close"
-                    variant="ghost"
-                    class="h-5 w-5"
-                    onClick={() => prompt.context.removeActive()}
-                    aria-label={language.t("prompt.context.removeActiveFile")}
-                  />
+                  <Show when={activeSelectionPreview()}>
+                    {(preview) => (
+                      <pre class="text-10-regular text-text-weak font-mono whitespace-pre-wrap leading-4">
+                        {preview()}
+                      </pre>
+                    )}
+                  </Show>
                 </div>
               )}
             </Show>
             <Show when={!prompt.context.activeTab() && !!activeFile()}>
               <button
                 type="button"
-                class="flex items-center gap-1.5 px-1.5 py-0.5 rounded-md bg-surface-base border border-border-base text-11-regular text-text-weak hover:bg-surface-raised-base-hover"
+                class="shrink-0 flex items-center gap-1.5 px-1.5 py-0.5 rounded-md bg-surface-base border border-border-base text-11-regular text-text-weak hover:bg-surface-raised-base-hover"
                 onClick={() => prompt.context.addActive()}
               >
                 <Icon name="plus-small" size="small" />
@@ -1526,32 +1552,47 @@ export const PromptInput: Component<PromptInputProps> = (props) => {
               </button>
             </Show>
             <For each={prompt.context.items()}>
-              {(item) => (
-                <div class="flex items-center gap-1.5 px-1.5 py-0.5 rounded-md bg-surface-base border border-border-base max-w-full">
-                  <FileIcon node={{ path: item.path, type: "file" }} class="shrink-0 size-3.5" />
-                  <div class="flex items-center text-11-regular min-w-0">
-                    <span class="text-text-weak whitespace-nowrap truncate min-w-0">{getDirectory(item.path)}</span>
-                    <span class="text-text-strong whitespace-nowrap">{getFilename(item.path)}</span>
-                    <Show when={item.selection}>
-                      {(sel) => (
-                        <span class="text-text-weak whitespace-nowrap ml-1">
-                          {sel().startLine === sel().endLine
-                            ? `:${sel().startLine}`
-                            : `:${sel().startLine}-${sel().endLine}`}
-                        </span>
+              {(item) => {
+                const preview = createMemo(() => selectionPreview(item.path, item.selection, item.preview))
+                return (
+                  <div class="shrink-0 flex flex-col gap-1 rounded-md bg-surface-base border border-border-base px-2 py-1 max-w-[320px]">
+                    <div class="flex items-center gap-1.5">
+                      <FileIcon node={{ path: item.path, type: "file" }} class="shrink-0 size-3.5" />
+                      <div class="flex items-center text-11-regular min-w-0">
+                        <span class="text-text-weak whitespace-nowrap truncate min-w-0">{getDirectory(item.path)}</span>
+                        <span class="text-text-strong whitespace-nowrap">{getFilename(item.path)}</span>
+                        <Show when={item.selection}>
+                          {(sel) => (
+                            <span class="text-text-weak whitespace-nowrap ml-1">
+                              {sel().startLine === sel().endLine
+                                ? `:${sel().startLine}`
+                                : `:${sel().startLine}-${sel().endLine}`}
+                            </span>
+                          )}
+                        </Show>
+                      </div>
+                      <IconButton
+                        type="button"
+                        icon="close"
+                        variant="ghost"
+                        class="h-5 w-5"
+                        onClick={() => prompt.context.remove(item.key)}
+                        aria-label={language.t("prompt.context.removeFile")}
+                      />
+                    </div>
+                    <Show when={item.comment}>
+                      {(comment) => <div class="text-11-regular text-text-strong">{comment()}</div>}
+                    </Show>
+                    <Show when={preview()}>
+                      {(content) => (
+                        <pre class="text-10-regular text-text-weak font-mono whitespace-pre-wrap leading-4">
+                          {content()}
+                        </pre>
                       )}
                     </Show>
                   </div>
-                  <IconButton
-                    type="button"
-                    icon="close"
-                    variant="ghost"
-                    class="h-5 w-5"
-                    onClick={() => prompt.context.remove(item.key)}
-                    aria-label={language.t("prompt.context.removeFile")}
-                  />
-                </div>
-              )}
+                )
+              }}
             </For>
           </div>
         </Show>
diff --git a/packages/app/src/context/prompt.tsx b/packages/app/src/context/prompt.tsx
index 993d7e7a8..a76d9d5f1 100644
--- a/packages/app/src/context/prompt.tsx
+++ b/packages/app/src/context/prompt.tsx
@@ -4,6 +4,7 @@ import { batch, createMemo, createRoot, onCleanup } from "solid-js"
 import { useParams } from "@solidjs/router"
 import type { FileSelection } from "@/context/file"
 import { Persist, persisted } from "@/utils/persist"
+import { checksum } from "@opencode-ai/util/encode"
 
 interface PartBase {
   content: string
@@ -41,6 +42,8 @@ export type FileContextItem = {
   type: "file"
   path: string
   selection?: FileSelection
+  comment?: string
+  preview?: string
 }
 
 export type ContextItem = FileContextItem
@@ -135,7 +138,11 @@ function createPromptSession(dir: string, id: string | undefined) {
     if (item.type !== "file") return item.type
     const start = item.selection?.startLine
     const end = item.selection?.endLine
-    return `${item.type}:${item.path}:${start}:${end}`
+    const key = `${item.type}:${item.path}:${start}:${end}`
+    const comment = item.comment?.trim()
+    if (!comment) return key
+    const digest = checksum(comment) ?? comment
+    return `${key}:c=${digest.slice(0, 8)}`
   }
 
   return {
diff --git a/packages/app/src/pages/session.tsx b/packages/app/src/pages/session.tsx
index ad6d360dc..1e0d7a89e 100644
--- a/packages/app/src/pages/session.tsx
+++ b/packages/app/src/pages/session.tsx
@@ -81,6 +81,7 @@ interface SessionReviewTabProps {
   diffStyle: DiffStyle
   onDiffStyleChange?: (style: DiffStyle) => void
   onViewFile?: (file: string) => void
+  onLineComment?: (comment: { file: string; selection: SelectedLineRange; comment: string; preview?: string }) => void
   classes?: {
     root?: string
     header?: string
@@ -166,6 +167,7 @@ function SessionReviewTab(props: SessionReviewTabProps) {
       onDiffStyleChange={props.onDiffStyleChange}
       onViewFile={props.onViewFile}
       readFile={readFile}
+      onLineComment={props.onLineComment}
     />
   )
 }
@@ -488,8 +490,36 @@ export default function Page() {
     setStore("expanded", id, status().type !== "idle")
   })
 
+  const selectionPreview = (path: string, selection: FileSelection) => {
+    const content = file.get(path)?.content?.content
+    if (!content) return undefined
+    const start = Math.max(1, Math.min(selection.startLine, selection.endLine))
+    const end = Math.max(selection.startLine, selection.endLine)
+    const lines = content.split("\n").slice(start - 1, end)
+    if (lines.length === 0) return undefined
+    return lines.slice(0, 2).join("\n")
+  }
+
   const addSelectionToContext = (path: string, selection: FileSelection) => {
-    prompt.context.add({ type: "file", path, selection })
+    const preview = selectionPreview(path, selection)
+    prompt.context.add({ type: "file", path, selection, preview })
+  }
+
+  const addCommentToContext = (input: {
+    file: string
+    selection: SelectedLineRange
+    comment: string
+    preview?: string
+  }) => {
+    const selection = selectionFromLines(input.selection)
+    const preview = input.preview ?? selectionPreview(input.file, selection)
+    prompt.context.add({
+      type: "file",
+      path: input.file,
+      selection,
+      comment: input.comment,
+      preview,
+    })
   }
 
   command.register(() => [
@@ -1402,6 +1432,7 @@ export default function Page() {
                                 diffs={diffs}
                                 view={view}
                                 diffStyle="unified"
+                                onLineComment={addCommentToContext}
                                 onViewFile={(path) => {
                                   const value = file.tab(path)
                                   tabs().open(value)
@@ -1717,6 +1748,7 @@ export default function Page() {
                                 view={view}
                                 diffStyle={layout.review.diffStyle()}
                                 onDiffStyleChange={layout.review.setDiffStyle}
+                                onLineComment={addCommentToContext}
                                 onViewFile={(path) => {
                                   const value = file.tab(path)
                                   tabs().open(value)