Link prior moderation actions to case decisions

src/lib/ui/components/moderation/ModerationDialog.svelte

@@ -7,9 +7,11 @@
         type ModerationCoverage,
         type ModerationGame,
         type ModerationScope,
-        type ModerationCase
+        type ModerationCase,
+        type ModerationCaseAction
     } from '$lib/moderation.js';
-    import { moderationGameName } from '$ui/moderation.js';
+    import { moderationActionName, moderationGameName } from '$ui/moderation.js';
+    import { timeFormat } from '$ui/stores/time-zone.js';
     import { serverTitle } from '$ui/server-labels.js';
     import { confirmAction } from '$ui/confirm.js';
     import Dialog from '../primitives/Dialog.svelte';
@@ -26,6 +28,7 @@
         admin,
         seed = {},
         assignees = [],
+        linkedActions = [],
         onsubmitted
     }: {
         open?: boolean;
@@ -43,6 +46,7 @@
         coverage: ModerationCoverage[];
         admin: boolean;
         assignees?: { id: string; username: string }[];
+        linkedActions?: ModerationCaseAction[];
         seed?: {
             game?: ModerationGame;
             guid?: string;
@@ -81,6 +85,21 @@
     const reasonBytes = $derived(new TextEncoder().encode(reason.trim()).length);
     const gameText = $derived(mode === 'restriction' || mode === 'action');
     let resolution = $state('resolved');
+    let actionReference = $state('');
+    const referenceActions = $derived(
+        linkedActions.filter((item) =>
+            resolution === 'warning_issued'
+                ? item.type === 'action' && item.kind === 'warn' && item.state === 'confirmed'
+                : resolution === 'restriction_applied' && item.type === 'restriction'
+        )
+    );
+    const referencedAction = $derived(
+        referenceActions.find((item) => `${item.type}:${item.id}` === actionReference)
+    );
+    $effect(() => {
+        void resolution;
+        actionReference = '';
+    });
     let busy = $state(false);
     let error = $state('');
     let uncertain = $state(false);
@@ -203,7 +222,10 @@
             id: seed.id,
             revision: seed.revision,
             status: resolution,
-            reason: reason.trim()
+            reason: reason.trim(),
+            ...(referencedAction
+                ? { actionReference: { type: referencedAction.type, id: referencedAction.id } }
+                : {})
         };
     }
 
@@ -468,6 +490,29 @@
                     separately, and send warnings through Live action. Choosing an outcome does not
                     change enforcement or send a warning.
                 </p>{/if}
+            {#if mode === 'resolve' && ['warning_issued', 'restriction_applied'].includes(resolution)}
+                <Field
+                    label="Supporting action"
+                    hint="Optional. Reference an existing linked action as the basis for this outcome."
+                >
+                    <Select
+                        bind:value={actionReference}
+                        options={[
+                            { value: '', label: 'No action reference' },
+                            ...referenceActions.map((item) => ({
+                                value: `${item.type}:${item.id}`,
+                                label: `${moderationActionName(item.kind)} · ${$timeFormat.dateTime(item.createdAt)} · ${item.reason}`
+                            }))
+                        ]}
+                    />
+                </Field>
+                {#if !referenceActions.length}<p class="hint">
+                        {resolution === 'warning_issued'
+                            ? 'No confirmed warnings are linked to this case.'
+                            : 'No restrictions are linked to this case.'} Use “Link existing action” on
+                        the case to add a prior action.
+                    </p>{/if}
+            {/if}
             {#if mode === 'reopen'}<p class="hint">
                     Reopening returns the case to Open and preserves its evidence, restrictions, and
                     earlier decisions.