From 930806690b9ec43a74db89f1acd217edf08d899b Mon Sep 17 00:00:00 2001
From: Jesse_Chen <chen.yue@mevixaga.com>
Date: Fri, 17 Jul 2026 21:12:46 +0800
Subject: [PATCH] feat: add shadcn calendar primitives

---
 frontend/package-lock.json                    |  33 +++
 frontend/package.json                         |   1 +
 frontend/src/components/ui/calendar.tsx       | 226 ++++++++++++++++++
 frontend/src/components/ui/popover.tsx        |  90 +++++++
 .../tests/birth-date-picker-contract.test.ts  |  11 +
 5 files changed, 361 insertions(+)
 create mode 100644 frontend/src/components/ui/calendar.tsx
 create mode 100644 frontend/src/components/ui/popover.tsx
 create mode 100644 frontend/tests/birth-date-picker-contract.test.ts

diff --git a/frontend/package-lock.json b/frontend/package-lock.json
index bf21968b..8deb8df5 100644
--- a/frontend/package-lock.json
+++ b/frontend/package-lock.json
@@ -19,6 +19,7 @@
         "lucide-react": "^1.24.0",
         "next": "16.2.10",
         "react": "19.2.4",
+        "react-day-picker": "^10.0.1",
         "react-dom": "19.2.4",
         "react-markdown": "^10.1.0",
         "remark-gfm": "^4.0.1",
@@ -575,6 +576,12 @@
         }
       }
     },
+    "node_modules/@date-fns/tz": {
+      "version": "1.5.0",
+      "resolved": "https://registry.npmjs.org/@date-fns/tz/-/tz-1.5.0.tgz",
+      "integrity": "sha512-lwYN/vDPeNRULcepoE/LO2Pgx+7/RV+S9ARfbc9lr2DtGkOD7pAiruHvbR1RX3Qyf6ja47EWJDMsNK5vK08DJg==",
+      "license": "MIT"
+    },
     "node_modules/@ecies/ciphers": {
       "version": "0.2.6",
       "resolved": "https://registry.npmjs.org/@ecies/ciphers/-/ciphers-0.2.6.tgz",
@@ -8681,6 +8688,32 @@
         "node": ">=0.10.0"
       }
     },
+    "node_modules/react-day-picker": {
+      "version": "10.0.1",
+      "resolved": "https://registry.npmjs.org/react-day-picker/-/react-day-picker-10.0.1.tgz",
+      "integrity": "sha512-eNh6BlwcYInWaJtRv18mXQ06Ys/H6rdTZAnTaSdOYJuTpwP1JMCHNd1FDRadA+gbeinq+psdULN5Xnowy9mV8w==",
+      "license": "MIT",
+      "dependencies": {
+        "@date-fns/tz": "^1.4.1",
+        "date-fns": "^4.1.0"
+      },
+      "engines": {
+        "node": ">=18"
+      },
+      "funding": {
+        "type": "individual",
+        "url": "https://github.com/sponsors/gpbl"
+      },
+      "peerDependencies": {
+        "@types/react": ">=16.8.0",
+        "react": ">=16.8.0"
+      },
+      "peerDependenciesMeta": {
+        "@types/react": {
+          "optional": true
+        }
+      }
+    },
     "node_modules/react-dom": {
       "version": "19.2.4",
       "resolved": "https://registry.npmjs.org/react-dom/-/react-dom-19.2.4.tgz",
diff --git a/frontend/package.json b/frontend/package.json
index 6e70a79b..1a815af9 100644
--- a/frontend/package.json
+++ b/frontend/package.json
@@ -23,6 +23,7 @@
     "lucide-react": "^1.24.0",
     "next": "16.2.10",
     "react": "19.2.4",
+    "react-day-picker": "^10.0.1",
     "react-dom": "19.2.4",
     "react-markdown": "^10.1.0",
     "remark-gfm": "^4.0.1",
diff --git a/frontend/src/components/ui/calendar.tsx b/frontend/src/components/ui/calendar.tsx
new file mode 100644
index 00000000..89894736
--- /dev/null
+++ b/frontend/src/components/ui/calendar.tsx
@@ -0,0 +1,226 @@
+"use client"
+
+import * as React from "react"
+import {
+  DayPicker,
+  getDefaultClassNames,
+  type DayButton,
+  type Locale,
+} from "react-day-picker"
+import { ChevronDownIcon, ChevronLeftIcon, ChevronRightIcon } from "lucide-react"
+
+import { cn } from "@/lib/utils"
+import { Button, buttonVariants } from "@/components/ui/button"
+
+function Calendar({
+  className,
+  classNames,
+  showOutsideDays = true,
+  captionLayout = "label",
+  buttonVariant = "ghost",
+  locale,
+  formatters,
+  components,
+  ...props
+}: React.ComponentProps<typeof DayPicker> & {
+  buttonVariant?: React.ComponentProps<typeof Button>["variant"]
+}) {
+  const defaultClassNames = getDefaultClassNames()
+
+  return (
+    <DayPicker
+      showOutsideDays={showOutsideDays}
+      className={cn(
+        "group/calendar bg-background p-2 [--cell-radius:var(--radius-md)] [--cell-size:--spacing(7)] in-data-[slot=card-content]:bg-transparent in-data-[slot=popover-content]:bg-transparent",
+        String.raw`rtl:**:[.rdp-button\\_next>svg]:rotate-180`,
+        String.raw`rtl:**:[.rdp-button\\_previous>svg]:rotate-180`,
+        className
+      )}
+      captionLayout={captionLayout}
+      locale={locale}
+      formatters={{
+        formatMonthDropdown: (date) =>
+          date.toLocaleString(locale?.code, { month: "short" }),
+        ...formatters,
+      }}
+      classNames={{
+        root: cn("w-fit", defaultClassNames.root),
+        months: cn(
+          "relative flex flex-col gap-4 md:flex-row",
+          defaultClassNames.months
+        ),
+        month: cn("flex w-full flex-col gap-4", defaultClassNames.month),
+        nav: cn(
+          "absolute inset-x-0 top-0 flex w-full items-center justify-between gap-1",
+          defaultClassNames.nav
+        ),
+        button_previous: cn(
+          buttonVariants({ variant: buttonVariant }),
+          "size-(--cell-size) p-0 select-none aria-disabled:opacity-50",
+          defaultClassNames.button_previous
+        ),
+        button_next: cn(
+          buttonVariants({ variant: buttonVariant }),
+          "size-(--cell-size) p-0 select-none aria-disabled:opacity-50",
+          defaultClassNames.button_next
+        ),
+        month_caption: cn(
+          "flex h-(--cell-size) w-full items-center justify-center px-(--cell-size)",
+          defaultClassNames.month_caption
+        ),
+        dropdowns: cn(
+          "flex h-(--cell-size) w-full items-center justify-center gap-1.5 text-sm font-medium",
+          defaultClassNames.dropdowns
+        ),
+        dropdown_root: cn(
+          "cn-calendar-dropdown-root relative rounded-(--cell-radius)",
+          defaultClassNames.dropdown_root
+        ),
+        dropdown: cn(
+          "absolute inset-0 bg-popover opacity-0",
+          defaultClassNames.dropdown
+        ),
+        caption_label: cn(
+          "font-medium select-none",
+          captionLayout === "label"
+            ? "cn-calendar-caption text-sm"
+            : "cn-calendar-caption-label flex items-center gap-1 rounded-(--cell-radius) text-sm [&>svg]:size-3.5 [&>svg]:text-muted-foreground",
+          defaultClassNames.caption_label
+        ),
+        month_grid: cn("w-full border-collapse", defaultClassNames.month_grid),
+        weekdays: cn("flex", defaultClassNames.weekdays),
+        weekday: cn(
+          "flex-1 rounded-(--cell-radius) text-[0.8rem] font-normal text-muted-foreground select-none",
+          defaultClassNames.weekday
+        ),
+        week: cn("mt-2 flex w-full", defaultClassNames.week),
+        week_number_header: cn(
+          "w-(--cell-size) select-none",
+          defaultClassNames.week_number_header
+        ),
+        week_number: cn(
+          "text-[0.8rem] text-muted-foreground select-none",
+          defaultClassNames.week_number
+        ),
+        day: cn(
+          "group/day relative aspect-square h-full w-full rounded-(--cell-radius) p-0 text-center select-none [&:last-child[data-selected=true]_button]:rounded-r-(--cell-radius)",
+          props.showWeekNumber
+            ? "[&:nth-child(2)[data-selected=true]_button]:rounded-l-(--cell-radius)"
+            : "[&:first-child[data-selected=true]_button]:rounded-l-(--cell-radius)",
+          defaultClassNames.day
+        ),
+        range_start: cn(
+          "relative isolate z-0 rounded-l-(--cell-radius) bg-muted after:absolute after:inset-y-0 after:right-0 after:w-4 after:bg-muted",
+          defaultClassNames.range_start
+        ),
+        range_middle: cn("rounded-none", defaultClassNames.range_middle),
+        range_end: cn(
+          "relative isolate z-0 rounded-r-(--cell-radius) bg-muted after:absolute after:inset-y-0 after:left-0 after:w-4 after:bg-muted",
+          defaultClassNames.range_end
+        ),
+        today: cn(
+          "rounded-(--cell-radius) bg-muted text-foreground data-[selected=true]:rounded-none",
+          defaultClassNames.today
+        ),
+        outside: cn(
+          "text-muted-foreground aria-selected:text-muted-foreground",
+          defaultClassNames.outside
+        ),
+        disabled: cn(
+          "text-muted-foreground opacity-50",
+          defaultClassNames.disabled
+        ),
+        hidden: cn("invisible", defaultClassNames.hidden),
+        ...classNames,
+      }}
+      components={{
+        Root: ({ className, rootRef, ...props }) => {
+          return (
+            <div
+              data-slot="calendar"
+              ref={rootRef}
+              className={cn(className)}
+              {...props}
+            />
+          )
+        },
+        Chevron: ({ className, orientation, ...props }) => {
+          if (orientation === "left") {
+            return (
+              <ChevronLeftIcon
+                className={cn("cn-rtl-flip size-4", className)}
+                {...props}
+              />
+            )
+          }
+
+          if (orientation === "right") {
+            return (
+              <ChevronRightIcon
+                className={cn("cn-rtl-flip size-4", className)}
+                {...props}
+              />
+            )
+          }
+
+          return <ChevronDownIcon className={cn("size-4", className)} {...props} />
+        },
+        DayButton: ({ ...props }) => (
+          <CalendarDayButton locale={locale} {...props} />
+        ),
+        WeekNumber: ({ children, ...props }) => {
+          return (
+            <td {...props}>
+              <div className="flex size-(--cell-size) items-center justify-center text-center">
+                {children}
+              </div>
+            </td>
+          )
+        },
+        ...components,
+      }}
+      {...props}
+    />
+  )
+}
+
+function CalendarDayButton({
+  className,
+  day,
+  modifiers,
+  locale,
+  ...props
+}: React.ComponentProps<typeof DayButton> & { locale?: Partial<Locale> }) {
+  const defaultClassNames = getDefaultClassNames()
+
+  const ref = React.useRef<HTMLButtonElement>(null)
+  React.useEffect(() => {
+    if (modifiers.focused) ref.current?.focus()
+  }, [modifiers.focused])
+
+  return (
+    <Button
+      ref={ref}
+      variant="ghost"
+      size="icon"
+      data-day={day.date.toLocaleDateString(locale?.code)}
+      data-selected-single={
+        modifiers.selected &&
+        !modifiers.range_start &&
+        !modifiers.range_end &&
+        !modifiers.range_middle
+      }
+      data-range-start={modifiers.range_start}
+      data-range-end={modifiers.range_end}
+      data-range-middle={modifiers.range_middle}
+      className={cn(
+        "relative isolate z-10 flex aspect-square size-auto w-full min-w-(--cell-size) flex-col gap-1 border-0 leading-none font-normal group-data-[focused=true]/day:relative group-data-[focused=true]/day:z-10 group-data-[focused=true]/day:border-ring group-data-[focused=true]/day:ring-[3px] group-data-[focused=true]/day:ring-ring/50 data-[range-end=true]:rounded-(--cell-radius) data-[range-end=true]:rounded-r-(--cell-radius) data-[range-end=true]:bg-primary data-[range-end=true]:text-primary-foreground data-[range-middle=true]:rounded-none data-[range-middle=true]:bg-muted data-[range-middle=true]:text-foreground data-[range-start=true]:rounded-(--cell-radius) data-[range-start=true]:rounded-l-(--cell-radius) data-[range-start=true]:bg-primary data-[range-start=true]:text-primary-foreground data-[selected-single=true]:bg-primary data-[selected-single=true]:text-primary-foreground dark:hover:text-foreground [&>span]:text-xs [&>span]:opacity-70",
+        defaultClassNames.day,
+        className
+      )}
+      {...props}
+    />
+  )
+}
+
+export { Calendar, CalendarDayButton }
diff --git a/frontend/src/components/ui/popover.tsx b/frontend/src/components/ui/popover.tsx
new file mode 100644
index 00000000..0b73c6b8
--- /dev/null
+++ b/frontend/src/components/ui/popover.tsx
@@ -0,0 +1,90 @@
+"use client"
+
+import * as React from "react"
+import { Popover as PopoverPrimitive } from "@base-ui/react/popover"
+
+import { cn } from "@/lib/utils"
+
+function Popover({ ...props }: PopoverPrimitive.Root.Props) {
+  return <PopoverPrimitive.Root data-slot="popover" {...props} />
+}
+
+function PopoverTrigger({ ...props }: PopoverPrimitive.Trigger.Props) {
+  return <PopoverPrimitive.Trigger data-slot="popover-trigger" {...props} />
+}
+
+function PopoverContent({
+  className,
+  align = "center",
+  alignOffset = 0,
+  side = "bottom",
+  sideOffset = 4,
+  ...props
+}: PopoverPrimitive.Popup.Props &
+  Pick<
+    PopoverPrimitive.Positioner.Props,
+    "align" | "alignOffset" | "side" | "sideOffset"
+  >) {
+  return (
+    <PopoverPrimitive.Portal>
+      <PopoverPrimitive.Positioner
+        align={align}
+        alignOffset={alignOffset}
+        side={side}
+        sideOffset={sideOffset}
+        className="isolate z-50"
+      >
+        <PopoverPrimitive.Popup
+          data-slot="popover-content"
+          className={cn(
+            "z-50 flex w-72 origin-(--transform-origin) flex-col gap-2.5 rounded-lg bg-popover p-2.5 text-sm text-popover-foreground shadow-md ring-1 ring-foreground/10 outline-hidden duration-100 data-[side=bottom]:slide-in-from-top-2 data-[side=inline-end]:slide-in-from-left-2 data-[side=inline-start]:slide-in-from-right-2 data-[side=left]:slide-in-from-right-2 data-[side=right]:slide-in-from-left-2 data-[side=top]:slide-in-from-bottom-2 data-open:animate-in data-open:fade-in-0 data-open:zoom-in-95 data-closed:animate-out data-closed:fade-out-0 data-closed:zoom-out-95",
+            className
+          )}
+          {...props}
+        />
+      </PopoverPrimitive.Positioner>
+    </PopoverPrimitive.Portal>
+  )
+}
+
+function PopoverHeader({ className, ...props }: React.ComponentProps<"div">) {
+  return (
+    <div
+      data-slot="popover-header"
+      className={cn("flex flex-col gap-0.5 text-sm", className)}
+      {...props}
+    />
+  )
+}
+
+function PopoverTitle({ className, ...props }: PopoverPrimitive.Title.Props) {
+  return (
+    <PopoverPrimitive.Title
+      data-slot="popover-title"
+      className={cn("font-medium", className)}
+      {...props}
+    />
+  )
+}
+
+function PopoverDescription({
+  className,
+  ...props
+}: PopoverPrimitive.Description.Props) {
+  return (
+    <PopoverPrimitive.Description
+      data-slot="popover-description"
+      className={cn("text-muted-foreground", className)}
+      {...props}
+    />
+  )
+}
+
+export {
+  Popover,
+  PopoverContent,
+  PopoverDescription,
+  PopoverHeader,
+  PopoverTitle,
+  PopoverTrigger,
+}
diff --git a/frontend/tests/birth-date-picker-contract.test.ts b/frontend/tests/birth-date-picker-contract.test.ts
new file mode 100644
index 00000000..9e7ffda0
--- /dev/null
+++ b/frontend/tests/birth-date-picker-contract.test.ts
@@ -0,0 +1,11 @@
+import assert from "node:assert/strict"
+import { existsSync, readFileSync } from "node:fs"
+import test from "node:test"
+
+const packageJson = readFileSync(new URL("../package.json", import.meta.url), "utf8")
+
+test("provides the shadcn calendar and popover primitives", () => {
+  assert.equal(existsSync(new URL("../src/components/ui/calendar.tsx", import.meta.url)), true)
+  assert.equal(existsSync(new URL("../src/components/ui/popover.tsx", import.meta.url)), true)
+  assert.match(packageJson, /"react-day-picker"/)
+})