from reportlab.pdfgen import canvas
from reportlab.pdfbase import pdfmetrics
from reportlab.pdfbase.ttfonts import TTFont
from PyPDF2 import PdfReader, PdfWriter
from datetime import datetime, timedelta
import random
import os
import uuid

BASE_DIR = os.path.dirname(os.path.abspath(__file__))
FONT_DIR = os.path.join(BASE_DIR, "../assets/fonts")


def generate_digi_pdf(data, template_path, output_path):
    from reportlab.lib.colors import HexColor
    TEMP_DIR = os.path.join(os.path.dirname(os.path.abspath(__file__)), "../static/tmp")
    os.makedirs(TEMP_DIR, exist_ok=True)

    packet_path = os.path.join(TEMP_DIR, f"temp_overlay_{uuid.uuid4().hex}.pdf")

    c = canvas.Canvas(packet_path)

    # calibri-bold
    FONT_CALIBRI_BOLD = os.path.join(FONT_DIR, "calibri-bold.ttf")
    # calibri-regular
    FONT_CALIBRI_REG = os.path.join(FONT_DIR, "calibri-regular.ttf")
    
    pdfmetrics.registerFont(TTFont("Calibri-Bold", FONT_CALIBRI_BOLD))
    pdfmetrics.registerFont(TTFont("Calibri", FONT_CALIBRI_REG))
    
    # --- Data ---
    cabang = data["cabang"]
    nama = data["nama"]
    alamat1 = data["alamat1"]
    alamat2 = data["alamat2"]
    kodpos = data["kodpos"]
    kota_kab = data["kota_kab"]
    provinsi = data["provinsi"]

    # Tanggal random dari 3 bulan ke belakang
    now = datetime.now()
    # List 3 bulan ke belakang (misal: Juli 2025 -> [4, 5, 6] = April, Mei, Juni)
    bulan_list = [(now.month - i - 1) % 12 + 1 for i in range(3)]
    tahun_list = [now.year if now.month - i - 1 >= 0 else now.year - 1 for i in range(3)]

    bulan_list = [(now.month - i - 1) % 12 + 1 for i in range(1, 4)]
    tahun_list = [now.year if now.month - i - 1 >= 0 else now.year - 1 for i in range(1, 4)]
    print("Bulan List:", bulan_list)

    # Pilih salah satu bulan dan tahun secara acak
    idx = random.randint(0, 2)
    bulan_target = bulan_list[idx]
    tahun_target = tahun_list[idx]

    awal = datetime(tahun_target, bulan_target, 1)
    # Cari akhir bulan target
    if bulan_target == 12:
        akhir = datetime(tahun_target + 1, 1, 1) - timedelta(days=1)
    else:
        akhir = datetime(tahun_target, bulan_target + 1, 1) - timedelta(days=1)
   
    # format 01-Feb-2022 to 28-Feb-2022
    periode_awal_str = f"{awal.day:02d}-{awal.strftime('%b').upper()}-{awal.year}"
    periode_akhir_str = f"{akhir.day:02d}-{akhir.strftime('%b').upper()}-{akhir.year}"
    periode = periode_awal_str + " to " + periode_akhir_str

    halaman = f"{random.randint(2, 9)}"

    # RANDOM NOMOR : 4133714
    customer_no = ''.join(random.choices('0123456789', k=7))

    # --- Draw ke PDF ---
    c.setFont("Calibri", 8)
    c.setFillColor(HexColor("#000000"))
    
    c.setFont("Calibri-Bold", 9)
    c.setFillColor(HexColor("#000000"))
    c.drawString(55, 662, nama)      

    c.drawString(425, 662, customer_no)
    batas_nama = 662
    c.drawString(425, batas_nama - 11, periode)
    c.drawString(425, batas_nama - 22, halaman)
    c.drawString(425, batas_nama - 32, cabang)

    batas_adr = 652
    c.drawString(55, batas_adr, alamat1)   
    c.drawString(55, batas_adr - 11, alamat2)   
    c.drawString(55, batas_adr - 21, kota_kab + ", " + provinsi)
    c.drawString(55, batas_adr - 31, 'INDONESIA' + ", " + kodpos)

    # bottom 
    c.setFont("Calibri", 9)
    c.drawString(295, 59, customer_no)
    c.drawString(530, 59, "Page 1 of " + halaman)
    c.save()

    background = PdfReader(template_path)
    overlay = PdfReader(packet_path)
    writer = PdfWriter()

    page = background.pages[0]
    page.merge_page(overlay.pages[0])
    writer.add_page(page)

    with open(output_path, "wb") as f:
        writer.write(f)

    # Bersihkan file sementara
    if os.path.exists(packet_path):
        os.remove(packet_path)