from langchain_core.prompts import ChatPromptTemplate
from llm_factory import get_llm
from fpdf import FPDF
import qrcode
import os

llm = get_llm(model_type="text", temperature=0.1)

system_prompt = """You are a Medical Report Generator.
Based on the diagnosis and action plan, write a formal medical report.
Include:
1. Patient Summary.
2. Clinical Findings.
3. Diagnosis.
4. Recommendations & Prescription.
5. A polite closing.

Format it as a clean text that can be put into a PDF.
"""

prompt = ChatPromptTemplate.from_messages([
    ("system", system_prompt),
    ("user", "Patient: {patient_info}\nDiagnosis: {diagnosis}\nPlan: {plan}")
])

chain = prompt | llm

async def generate_report_content(patient_info: dict, diagnosis: str, plan: str) -> str:
    response = await chain.ainvoke({
        "patient_info": str(patient_info),
        "diagnosis": diagnosis,
        "plan": plan
    })
    return response.content

def create_pdf_report(content: str, patient_name: str, filename: str = "report.pdf"):
    pdf = FPDF()
    pdf.add_page()
    pdf.set_font("Arial", size=12)
    
    # Header
    pdf.set_font("Arial", 'B', 16)
    pdf.cell(200, 10, txt="Medical Report", ln=1, align='C')
    pdf.set_font("Arial", size=12)
    pdf.cell(200, 10, txt="Dr. Amine Tounsi", ln=1, align='C')
    pdf.ln(10)
    
    # Content
    # Sanitize content for FPDF (latin-1)
    replacements = {
        "\u2019": "'",  # Smart quote
        "\u2018": "'",
        "\u201c": '"',  # Smart double quotes
        "\u201d": '"',
        "\u2013": "-",  # En dash
        "\u2014": "-",  # Em dash
        "\u2264": "<=", # Less than or equal
        "\u2265": ">=", # Greater than or equal
        "…": "...",
        "–": "-"
    }
    for char, replacement in replacements.items():
        content = content.replace(char, replacement)
    
    # Final fallback: encode to latin-1, replace errors with '?', then decode
    content = content.encode('latin-1', 'replace').decode('latin-1')

    pdf.multi_cell(0, 10, txt=content)
    
    # QR Code
    qr = qrcode.QRCode(version=1, box_size=10, border=5)
    qr.add_data(f"Patient: {patient_name} - Verified by Dr. Tounsi")
    qr.make(fit=True)
    img = qr.make_image(fill_color="black", back_color="white")
    img.save("temp_qr.png")
    
    pdf.ln(10)
    pdf.image("temp_qr.png", w=30)
    os.remove("temp_qr.png")
    
    # Ensure directory exists
    os.makedirs("reports", exist_ok=True)
    pdf.output(f"reports/{filename}")
    return f"reports/{filename}"