feat: add import/export for JSON, CSV, and Trello formats

src/components/boards/BoardList.tsx

@@ -4,6 +4,7 @@ import { Button } from "@/components/ui/button";
 import { useAppStore } from "@/stores/app-store";
 import { BoardCard } from "@/components/boards/BoardCard";
 import { NewBoardDialog } from "@/components/boards/NewBoardDialog";
+import { ImportExportButtons } from "@/components/import-export/ImportExportButtons";
 
 export function BoardList() {
   const boards = useAppStore((s) => s.boards);
@@ -27,10 +28,13 @@ export function BoardList() {
           <p className="font-mono text-sm text-pylon-text-secondary">
             Create your first board
           </p>
-          <Button onClick={() => setDialogOpen(true)}>
+          <div className="flex items-center gap-2">
-            <Plus className="size-4" />
+            <Button onClick={() => setDialogOpen(true)}>
-            New Board
+              <Plus className="size-4" />
-          </Button>
+              New Board
+            </Button>
+            <ImportExportButtons />
+          </div>
         </div>
         <NewBoardDialog open={dialogOpen} onOpenChange={setDialogOpen} />
       </>
@@ -45,10 +49,13 @@ export function BoardList() {
           <h2 className="font-mono text-xs font-semibold uppercase tracking-widest text-pylon-text-secondary">
             Your Boards
           </h2>
-          <Button size="sm" onClick={() => setDialogOpen(true)}>
+          <div className="flex items-center gap-2">
-            <Plus className="size-4" />
+            <ImportExportButtons />
-            New
+            <Button size="sm" onClick={() => setDialogOpen(true)}>
-          </Button>
+              <Plus className="size-4" />
+              New
+            </Button>
+          </div>
         </div>
 
         {/* Board grid */}

src/components/import-export/ImportExportButtons.tsx

@@ -0,0 +1,125 @@
+import { useRef } from "react";
+import { Download, Upload } from "lucide-react";
+import { Button } from "@/components/ui/button";
+import {
+  DropdownMenu,
+  DropdownMenuContent,
+  DropdownMenuItem,
+  DropdownMenuTrigger,
+} from "@/components/ui/dropdown-menu";
+import { useAppStore } from "@/stores/app-store";
+import { useBoardStore } from "@/stores/board-store";
+import { saveBoard } from "@/lib/storage";
+import {
+  exportBoardAsJson,
+  exportBoardAsCsv,
+  importBoardFromJson,
+  importFromTrelloJson,
+} from "@/lib/import-export";
+
+function downloadBlob(content: string, filename: string, mimeType: string) {
+  const blob = new Blob([content], { type: mimeType });
+  const url = URL.createObjectURL(blob);
+  const a = document.createElement("a");
+  a.href = url;
+  a.download = filename;
+  document.body.appendChild(a);
+  a.click();
+  document.body.removeChild(a);
+  URL.revokeObjectURL(url);
+}
+
+export function ImportExportButtons() {
+  const fileInputRef = useRef<HTMLInputElement>(null);
+  const board = useBoardStore((s) => s.board);
+  const refreshBoards = useAppStore((s) => s.refreshBoards);
+  const setView = useAppStore((s) => s.setView);
+  const addRecentBoard = useAppStore((s) => s.addRecentBoard);
+  const openBoard = useBoardStore((s) => s.openBoard);
+
+  function handleExportJson() {
+    if (!board) return;
+    const json = exportBoardAsJson(board);
+    const safeName = board.title.replace(/[^a-zA-Z0-9-_]/g, "_");
+    downloadBlob(json, `${safeName}.json`, "application/json");
+  }
+
+  function handleExportCsv() {
+    if (!board) return;
+    const csv = exportBoardAsCsv(board);
+    const safeName = board.title.replace(/[^a-zA-Z0-9-_]/g, "_");
+    downloadBlob(csv, `${safeName}.csv`, "text/csv");
+  }
+
+  function handleImportClick() {
+    fileInputRef.current?.click();
+  }
+
+  async function handleFileSelected(e: React.ChangeEvent<HTMLInputElement>) {
+    const file = e.target.files?.[0];
+    if (!file) return;
+
+    try {
+      const text = await file.text();
+      let imported;
+
+      // Try to detect if it's a Trello export
+      const parsed = JSON.parse(text);
+      if (parsed.lists && parsed.cards && !parsed.columns) {
+        // Looks like Trello format
+        imported = importFromTrelloJson(text);
+      } else {
+        imported = importBoardFromJson(text);
+      }
+
+      await saveBoard(imported);
+      await refreshBoards();
+      await openBoard(imported.id);
+      setView({ type: "board", boardId: imported.id });
+      addRecentBoard(imported.id);
+    } catch (err) {
+      console.error("Import failed:", err);
+      // Could show a toast here in the future
+    }
+
+    // Reset the input so the same file can be re-imported
+    if (fileInputRef.current) {
+      fileInputRef.current.value = "";
+    }
+  }
+
+  return (
+    <div className="flex gap-2">
+      {/* Import button */}
+      <Button variant="outline" size="sm" onClick={handleImportClick}>
+        <Upload className="size-4" />
+        Import
+      </Button>
+      <input
+        ref={fileInputRef}
+        type="file"
+        accept=".json"
+        onChange={handleFileSelected}
+        className="hidden"
+      />
+
+      {/* Export dropdown */}
+      <DropdownMenu>
+        <DropdownMenuTrigger asChild>
+          <Button variant="outline" size="sm" disabled={!board}>
+            <Download className="size-4" />
+            Export
+          </Button>
+        </DropdownMenuTrigger>
+        <DropdownMenuContent align="end">
+          <DropdownMenuItem onClick={handleExportJson}>
+            Export as JSON
+          </DropdownMenuItem>
+          <DropdownMenuItem onClick={handleExportCsv}>
+            Export as CSV
+          </DropdownMenuItem>
+        </DropdownMenuContent>
+      </DropdownMenu>
+    </div>
+  );
+}

src/lib/import-export.ts

@@ -0,0 +1,230 @@
+import { ulid } from "ulid";
+import { boardSchema } from "@/lib/schemas";
+import type { Board, Card, Column, Label, ChecklistItem } from "@/types/board";
+
+// ---------------------------------------------------------------------------
+// Export: JSON
+// ---------------------------------------------------------------------------
+
+export function exportBoardAsJson(board: Board): string {
+  return JSON.stringify(board, null, 2);
+}
+
+// ---------------------------------------------------------------------------
+// Export: CSV
+// ---------------------------------------------------------------------------
+
+function escapeCsv(value: string): string {
+  if (value.includes(",") || value.includes('"') || value.includes("\n")) {
+    return `"${value.replace(/"/g, '""')}"`;
+  }
+  return value;
+}
+
+export function exportBoardAsCsv(board: Board): string {
+  const headers = [
+    "board",
+    "column",
+    "title",
+    "description",
+    "labels",
+    "dueDate",
+    "checklistTotal",
+    "checklistDone",
+    "createdAt",
+    "updatedAt",
+  ];
+
+  const rows: string[] = [headers.join(",")];
+
+  for (const column of board.columns) {
+    for (const cardId of column.cardIds) {
+      const card = board.cards[cardId];
+      if (!card) continue;
+
+      const labelNames = card.labels
+        .map((lid) => board.labels.find((l) => l.id === lid)?.name ?? lid)
+        .join(";");
+
+      const checklistTotal = card.checklist.length;
+      const checklistDone = card.checklist.filter((item) => item.checked).length;
+
+      const row = [
+        escapeCsv(board.title),
+        escapeCsv(column.title),
+        escapeCsv(card.title),
+        escapeCsv(card.description),
+        escapeCsv(labelNames),
+        card.dueDate ?? "",
+        String(checklistTotal),
+        String(checklistDone),
+        card.createdAt,
+        card.updatedAt,
+      ];
+
+      rows.push(row.join(","));
+    }
+  }
+
+  return rows.join("\n");
+}
+
+// ---------------------------------------------------------------------------
+// Import: JSON (OpenPylon format)
+// ---------------------------------------------------------------------------
+
+export function importBoardFromJson(jsonString: string): Board {
+  const data = JSON.parse(jsonString);
+  const board = boardSchema.parse(data) as Board;
+  return board;
+}
+
+// ---------------------------------------------------------------------------
+// Import: Trello JSON
+// ---------------------------------------------------------------------------
+
+interface TrelloCard {
+  name: string;
+  desc?: string;
+  due?: string | null;
+  labels?: { name: string; color: string }[];
+  idList: string;
+  closed?: boolean;
+  checklists?: {
+    name: string;
+    checkItems: { name: string; state: "complete" | "incomplete" }[];
+  }[];
+}
+
+interface TrelloList {
+  id: string;
+  name: string;
+  closed?: boolean;
+}
+
+interface TrelloBoard {
+  name: string;
+  lists?: TrelloList[];
+  cards?: TrelloCard[];
+  labels?: { name: string; color: string }[];
+}
+
+const TRELLO_COLOR_MAP: Record<string, string> = {
+  green: "#22c55e",
+  yellow: "#eab308",
+  orange: "#f97316",
+  red: "#ef4444",
+  purple: "#8b5cf6",
+  blue: "#3b82f6",
+  sky: "#0ea5e9",
+  lime: "#84cc16",
+  pink: "#ec4899",
+  black: "#1e293b",
+};
+
+export function importFromTrelloJson(jsonString: string): Board {
+  const data = JSON.parse(jsonString) as TrelloBoard;
+
+  const ts = new Date().toISOString();
+  const boardId = ulid();
+
+  // Map Trello labels
+  const labels: Label[] = [];
+  const trelloLabelMap = new Map<string, string>(); // trello label key -> our label id
+
+  if (data.labels) {
+    for (const tLabel of data.labels) {
+      if (!tLabel.name && !tLabel.color) continue;
+      const id = ulid();
+      const color = TRELLO_COLOR_MAP[tLabel.color] ?? "#6366f1";
+      labels.push({ id, name: tLabel.name || tLabel.color, color });
+      trelloLabelMap.set(`${tLabel.name}-${tLabel.color}`, id);
+    }
+  }
+
+  // Map Trello lists -> columns, filtering out archived lists
+  const openLists = (data.lists ?? []).filter((l) => !l.closed);
+  const listIdToColumnId = new Map<string, string>();
+  const columns: Column[] = openLists.map((list) => {
+    const colId = ulid();
+    listIdToColumnId.set(list.id, colId);
+    return {
+      id: colId,
+      title: list.name,
+      cardIds: [],
+      width: "standard" as const,
+    };
+  });
+
+  // Map Trello cards
+  const cards: Record<string, Card> = {};
+
+  for (const tCard of data.cards ?? []) {
+    if (tCard.closed) continue;
+
+    const columnId = listIdToColumnId.get(tCard.idList);
+    if (!columnId) continue;
+
+    const cardId = ulid();
+
+    // Map labels
+    const cardLabelIds: string[] = [];
+    if (tCard.labels) {
+      for (const tl of tCard.labels) {
+        const key = `${tl.name}-${tl.color}`;
+        const existingId = trelloLabelMap.get(key);
+        if (existingId) {
+          cardLabelIds.push(existingId);
+        }
+      }
+    }
+
+    // Map checklists
+    const checklist: ChecklistItem[] = [];
+    if (tCard.checklists) {
+      for (const cl of tCard.checklists) {
+        for (const item of cl.checkItems) {
+          checklist.push({
+            id: ulid(),
+            text: item.name,
+            checked: item.state === "complete",
+          });
+        }
+      }
+    }
+
+    const card: Card = {
+      id: cardId,
+      title: tCard.name,
+      description: tCard.desc ?? "",
+      labels: cardLabelIds,
+      checklist,
+      dueDate: tCard.due ?? null,
+      attachments: [],
+      createdAt: ts,
+      updatedAt: ts,
+    };
+
+    cards[cardId] = card;
+
+    // Add card to column
+    const col = columns.find((c) => c.id === columnId);
+    if (col) {
+      col.cardIds.push(cardId);
+    }
+  }
+
+  const board: Board = {
+    id: boardId,
+    title: data.name || "Imported Board",
+    color: "#6366f1",
+    createdAt: ts,
+    updatedAt: ts,
+    columns,
+    cards,
+    labels,
+    settings: { attachmentMode: "link" },
+  };
+
+  return board;
+}