"""
Currency Converter — customtkinter edition
Rounded corners, dark/light mode toggle.
Dependencies: pip install requests pyperclip customtkinter
"""

import customtkinter as ctk
import threading
import time
import re
import platform

try:
    import requests
    HAS_REQUESTS = True
except ImportError:
    HAS_REQUESTS = False

try:
    import pyperclip
    HAS_PYPERCLIP = True
except ImportError:
    HAS_PYPERCLIP = False

IS_MAC = platform.system() == "Darwin"
ctk.set_appearance_mode("dark")
ctk.set_default_color_theme("blue")

FONT   = "SF Pro Text"    if IS_MAC else "Helvetica"
FONT_D = "SF Pro Display" if IS_MAC else "Helvetica"
ACCENT = "#0A84FF"
GREEN  = "#30D158"

# Dynamic colors per mode — (dark, light)
def T(dark, light):
    """Return a tuple customtkinter uses for dark/light."""
    return (dark, light)

# Color pairs
C_BG    = T("#1C1C1E", "#F2F2F7")
C_PANEL = T("#2C2C2E", "#FFFFFF")
C_PILL  = T("#3A3A3C", "#E5E5EA")
C_PILLH = T("#555558", "#D1D1D6")
C_WHITE = T("#FFFFFF", "#000000")
C_GREY  = T("#8E8E93", "#6C6C70")
C_GREY2 = T("#636366", "#8E8E93")
C_SEP   = T("#38383A", "#C6C6C8")

FALLBACK_RATES = {
    "USD": 1.0,   "VND": 25450.0, "EUR": 0.92,  "GBP": 0.79,
    "JPY": 149.5, "KRW": 1340.0,  "CNY": 7.24,  "SGD": 1.35,
    "THB": 35.5,  "MYR": 4.72,    "AUD": 1.54,  "CAD": 1.37,
    "CHF": 0.90,  "HKD": 7.82,    "INR": 83.2,  "NZD": 1.65,
    "SEK": 10.5,  "NOK": 10.8,    "DKK": 6.89,  "BRL": 4.97,
    "MXN": 17.2,  "ZAR": 18.6,    "TRY": 32.1,  "RUB": 90.5,
    "AED": 3.67,  "SAR": 3.75,    "ILS": 3.72,  "PLN": 3.98,
    "CZK": 23.1,  "HUF": 358.0,   "RON": 4.59,  "IDR": 15750.0,
    "PHP": 56.8,  "PKR": 278.0,   "BDT": 110.0, "NGN": 1550.0,
}
CURRENCIES = sorted(FALLBACK_RATES.keys())
SYMBOLS = {
    "USD":"$",  "VND":"₫",  "EUR":"€",  "GBP":"£",  "JPY":"¥",
    "KRW":"₩",  "CNY":"¥",  "SGD":"S$", "THB":"฿",  "MYR":"RM",
    "AUD":"A$", "CAD":"C$", "CHF":"Fr", "HKD":"HK$","INR":"₹",
    "NZD":"NZ$","SEK":"kr", "NOK":"kr", "DKK":"kr", "BRL":"R$",
    "MXN":"$",  "ZAR":"R",  "TRY":"₺",  "RUB":"₽",  "AED":"د.إ",
    "SAR":"﷼",  "ILS":"₪",  "PLN":"zł", "CZK":"Kč", "HUF":"Ft",
    "RON":"lei","IDR":"Rp", "PHP":"₱",  "PKR":"₨",  "BDT":"৳",
    "NGN":"₦",
}

FALLBACK_RATES
class RateCache:
    def __init__(self):
        self.rates = dict(FALLBACK_RATES)
        self._lock = threading.Lock()

    def fetch(self, cb=None):
        if not HAS_REQUESTS:
            if cb: cb(False); return
        try:
            r = requests.get("https://open.er-api.com/v6/latest/USD", timeout=8)
            d = r.json()
            if d.get("result") == "success":
                with self._lock: self.rates = d["rates"]
                if cb: cb(True)
            else:
                if cb: cb(False)
        except Exception:
            if cb: cb(False)

    def convert(self, amt, frm, to):
        with self._lock: r = self.rates
        return amt / r[frm] * r[to]

    def rate_str(self, frm, to):
        with self._lock: r = self.rates
        v = r[to] / r[frm]
        return f"1 {frm} = {v:,.4f} {to}" if v >= 1 else f"1 {frm} = {v:.6f} {to}"


# ── App ───────────────────────────────────────────────────────────────────────
class App(ctk.CTk):
    def __init__(self):
        super().__init__()
        self.cache = RateCache()
        self._result_str = ""
        self._build_window()
        self._build_ui()
        threading.Thread(target=self.cache.fetch,
                         kwargs={"cb": self._on_rates}, daemon=True).start()
        self._live_convert()

    def _build_window(self):
        self.title("Currency")
        self.configure(fg_color=C_BG)
        self.resizable(False, False)
        W, H = 320, 420
        sw, sh = self.winfo_screenwidth(), self.winfo_screenheight()
        self.geometry(f"{W}x{H}+{(sw-W)//2}+{(sh-H)//2}")

    def _build_ui(self):
        self.from_var = ctk.StringVar(value="USD")
        self.to_var   = ctk.StringVar(value="VND")

        # ── Currency selector row ─────────────────────────────────────────
        top = ctk.CTkFrame(self, fg_color=C_BG)
        top.pack(fill="x", padx=16, pady=(16, 0))
        top.columnconfigure(0, weight=1)
        top.columnconfigure(2, weight=1)

        # FROM dropdown
        self._from_dd = ctk.CTkOptionMenu(
            top, variable=self.from_var, values=CURRENCIES,
            width=110, height=32, corner_radius=8,
            fg_color=C_PILL, button_color=C_PILL,
            button_hover_color=C_PILLH,
            text_color=C_WHITE, dropdown_fg_color=C_PANEL,
            dropdown_hover_color=C_PILL,
            font=(FONT, 13, "bold"),
            command=lambda _: self._on_from_change())
        self._from_dd.grid(row=0, column=0, sticky="ew")

        # Swap button
        swap_btn = ctk.CTkButton(
            top, text="⇄", width=36, height=32,
            corner_radius=8,
            fg_color=C_PILL, hover_color=C_PILLH,
            text_color=C_GREY,
            font=(FONT, 14, "bold"),
            command=self._swap)
        swap_btn.grid(row=0, column=1, padx=8)

        # TO dropdown
        self._to_dd = ctk.CTkOptionMenu(
            top, variable=self.to_var, values=CURRENCIES,
            width=110, height=32, corner_radius=8,
            fg_color=C_PILL, button_color=C_PILL,
            button_hover_color=C_PILLH,
            text_color=C_WHITE, dropdown_fg_color=C_PANEL,
            dropdown_hover_color=C_PILL,
            font=(FONT, 13, "bold"),
            command=lambda _: self._live_convert())
        self._to_dd.grid(row=0, column=2, sticky="ew")

        # ── Rate label ────────────────────────────────────────────────────
        self._rate_lbl = ctk.CTkLabel(self, text="",
                                      font=(FONT, 11),
                                      text_color=C_GREY)
        self._rate_lbl.pack(pady=(10, 0))

        # Separator
        ctk.CTkFrame(self, height=1, fg_color=C_SEP, corner_radius=0)\
            .pack(fill="x", padx=16, pady=(10, 0))

        # ── INPUT card ────────────────────────────────────────────────────
        in_card = ctk.CTkFrame(self, fg_color=C_PANEL, corner_radius=12)
        in_card.pack(fill="x", padx=16, pady=(12, 0))

        in_hdr = ctk.CTkFrame(in_card, fg_color=C_PANEL)
        in_hdr.pack(fill="x", padx=14, pady=(10, 0))

        self._in_tag = ctk.CTkLabel(in_hdr, text="USD  $",
                                    font=(FONT, 10, "bold"),
                                    text_color=ACCENT)
        self._in_tag.pack(side="left")

        self._copy_in_btn = ctk.CTkButton(
            in_hdr, text="⎘", width=28, height=22,
            corner_radius=6,
            fg_color="transparent", hover_color=C_PILL,
            text_color=C_GREY2, font=(FONT, 11),
            command=self._copy_input)
        self._copy_in_btn.pack(side="right")

        self.amount_var = ctk.StringVar(value="1")
        self._entry = ctk.CTkEntry(
            in_card, textvariable=self.amount_var,
            font=(FONT_D, 38, "bold"),
            fg_color=C_PANEL, border_width=0,
            text_color=C_WHITE,
            justify="center", width=280, height=56)
        self._entry.pack(pady=(2, 12), padx=14)
        self._entry.bind("<KeyRelease>", lambda e: self._live_convert())
        self._entry.bind("<Return>",     lambda e: self._live_convert())

        # ── Swap vertical ─────────────────────────────────────────────────
        mid = ctk.CTkFrame(self, fg_color=C_BG)
        mid.pack(pady=8)
        ctk.CTkButton(mid, text="↕", width=32, height=32,
                      corner_radius=16,
                      fg_color=C_PILL, hover_color=C_PILLH,
                      text_color=C_GREY, font=(FONT, 13),
                      command=self._swap).pack()

        # ── OUTPUT card ───────────────────────────────────────────────────
        out_card = ctk.CTkFrame(self, fg_color=C_PANEL, corner_radius=12)
        out_card.pack(fill="x", padx=16, pady=(0, 12))

        out_hdr = ctk.CTkFrame(out_card, fg_color=C_PANEL)
        out_hdr.pack(fill="x", padx=14, pady=(10, 0))

        self._out_tag = ctk.CTkLabel(out_hdr, text="VND  ₫",
                                     font=(FONT, 10, "bold"),
                                     text_color=ACCENT)
        self._out_tag.pack(side="left")

        self._copy_out_btn = ctk.CTkButton(
            out_hdr, text="⎘", width=28, height=22,
            corner_radius=6,
            fg_color="transparent", hover_color=C_PILL,
            text_color=C_GREY2, font=(FONT, 11),
            command=self._copy_output)
        self._copy_out_btn.pack(side="right")

        self._result_lbl = ctk.CTkLabel(
            out_card, text="—",
            font=(FONT_D, 38, "bold"),
            text_color=C_WHITE)
        self._result_lbl.pack(pady=(2, 12))

        # ── Status bar ────────────────────────────────────────────────────
        bot = ctk.CTkFrame(self, fg_color=C_BG)
        bot.pack(fill="x", padx=16, pady=(0, 12))

        self._status_lbl = ctk.CTkLabel(bot, text="● connecting…",
                                        font=(FONT, 9), text_color=C_GREY2)
        self._status_lbl.pack(side="left")

        # Dark / Light toggle
        self._mode = "dark"
        self._mode_btn = ctk.CTkButton(
            bot, text="☀", width=28, height=22,
            corner_radius=6,
            fg_color="transparent", hover_color=C_PILL,
            text_color=C_GREY2, font=(FONT, 13),
            command=self._toggle_mode)
        self._mode_btn.pack(side="right", padx=(6, 0))

        ctk.CTkLabel(bot, text="Currency Converter",
                     font=(FONT, 9), text_color=C_GREY2).pack(side="right")

    # ── Logic ─────────────────────────────────────────────────────────────────
    def _toggle_mode(self):
        if self._mode == "dark":
            self._mode = "light"
            ctk.set_appearance_mode("light")
            self._mode_btn.configure(text="🌙")
        else:
            self._mode = "dark"
            ctk.set_appearance_mode("dark")
            self._mode_btn.configure(text="☀")

    def _on_from_change(self):
        self._refresh_tags()
        self._live_convert()

    def _refresh_tags(self):
        f, t = self.from_var.get(), self.to_var.get()
        self._in_tag.configure(text=f"{f}  {SYMBOLS.get(f,'')}")
        self._out_tag.configure(text=f"{t}  {SYMBOLS.get(t,'')}")

    def _get_amount(self):
        raw = self.amount_var.get().strip().replace(",", "")
        m = re.findall(r"[\d.]+", raw)
        if not m: return None
        try: return float(m[0])
        except ValueError: return None

    def _fmt(self, v):
        if v >= 1000: return f"{v:,.2f}"
        if v >= 1:    return f"{v:.4f}"
        return f"{v:.6f}"

    def _live_convert(self):
        self._refresh_tags()
        amt = self._get_amount()
        if amt is None: return
        frm, to = self.from_var.get(), self.to_var.get()
        try:
            result = self.cache.convert(amt, frm, to)
            self._result_str = self._fmt(result)
            self._result_lbl.configure(text=self._result_str, text_color=C_WHITE)
            self._rate_lbl.configure(text=self.cache.rate_str(frm, to))
        except Exception:
            pass

    def _swap(self):
        a, b = self.from_var.get(), self.to_var.get()
        res = self._result_str.replace(",", "") if self._result_str else None
        self.from_var.set(b)
        self.to_var.set(a)
        if res:
            try: self.amount_var.set(res)
            except Exception: pass
        self._refresh_tags()
        self._live_convert()

    def _do_copy(self, btn, value):
        if not value: return
        try:
            if HAS_PYPERCLIP: pyperclip.copy(value)
            else: self.clipboard_clear(); self.clipboard_append(value)
        except Exception: pass
        btn.configure(text="✓", text_color=GREEN)
        self.after(1200, lambda: btn.configure(text="⎘", text_color=C_GREY2))

    def _copy_input(self):
        self._do_copy(self._copy_in_btn, self.amount_var.get())

    def _copy_output(self):
        self._do_copy(self._copy_out_btn, self._result_str)

    def _on_rates(self, live):
        def _u():
            self._status_lbl.configure(
                text="● live rates" if live else "● offline",
                text_color=GREEN if live else C_GREY2)
            self._live_convert()
        self.after(0, _u)

def main():
    print("💱 Currency  |  ⌘+Shift+T")
    App().mainloop()

if __name__ == "__main__":
    main()