package main

import (
	"fmt"
	"image/color"
	"machine"
	"sync"
	"time"

	"tinygo.org/x/drivers/ssd1306"
	"tinygo.org/x/tinyfont"
	"tinygo.org/x/tinyfont/freemono"
	"tinygo.org/x/tinyfont/proggy"
)

var (
	white = color.RGBA{R: 255, G: 255, B: 255, A: 255}
	black = color.RGBA{R: 0, G: 0, B: 0, A: 255}

	mu          sync.Mutex
	currentTime time.Time
)

func main() {
	// Configure I2C0 with your pins: GP16 (SDA) and GP17 (SCL)
	machine.I2C0.Configure(machine.I2CConfig{
		Frequency: 400 * machine.KHz,
		SDA:       machine.GP16,
		SCL:       machine.GP17,
	})

	display := ssd1306.NewI2C(machine.I2C0)
	display.Configure(ssd1306.Config{
		Address: 0x3C,
		Width:   128,
		Height:  64,
	})

	// 1. Splash / Connection screen
	display.ClearBuffer()
	tinyfont.WriteLine(display, &proggy.TinySZ8pt7b, 8, 32, "Connecting Wi-Fi...", white)
	display.Display()

	// 2. Initialize Wi-Fi hardware and lneto stack
  netStack, err := InitNetwork(WifiSSID, WifiPass)
	if err != nil {
		display.ClearBuffer()
		tinyfont.WriteLine(display, &proggy.TinySZ8pt7b, 8, 32, "Wi-Fi Error!", white)
		display.Display()
		println("Wi-Fi init error:", err.Error())
		for {}
	}

	// 3. NTP Fetch Status
	display.ClearBuffer()
	tinyfont.WriteLine(display, &proggy.TinySZ8pt7b, 8, 32, "Syncing NTP...", white)
	display.Display()

  syncedTime, err := netStack.FetchNTP(NtpServer)
	if err != nil {
		println("Initial NTP sync error:", err.Error())
		currentTime = time.Date(2026, time.September, 7, 12, 0, 0, 0, time.UTC)
	} else {
		currentTime = syncedTime
	}

	// 4. Background NTP re-sync routine (every 1 hour)
	go func() {
		resyncTicker := time.NewTicker(1 * time.Hour)
		for range resyncTicker.C {
      if t, err := netStack.FetchNTP(NtpServer); err == nil {
				mu.Lock()
				currentTime = t
				mu.Unlock()
			}
		}
	}()

	// 5. 1Hz UI rendering loop
	ticker := time.NewTicker(1 * time.Second)
	for range ticker.C {
		mu.Lock()
		currentTime = currentTime.Add(1 * time.Second)
		now := currentTime
		mu.Unlock()

		// Optional: Apply timezone offset if needed (e.g. now = now.Add(-4 * time.Hour))
		timeStr := fmt.Sprintf("%02d:%02d:%02d", now.Hour(), now.Minute(), now.Second())
		dateStr := now.Format("Mon, Jan 02 2006")

		display.ClearBuffer()

		// Top: Date with Proggy
		tinyfont.WriteLine(display, &proggy.TinySZ8pt7b, 16, 14, dateStr, white)
		// Center: Time with Freemono Bold 12pt
		tinyfont.WriteLine(display, &freemono.Bold12pt7b, 6, 44, timeStr, white)

		display.Display()
	}
}