from pydantic import BaseModel, Field
from typing import List, Optional, Literal
from datetime import date

# ---------------------------------------------------------
# 0. Itemized Claim Item Schema
# (Individual item evaluation)
# ---------------------------------------------------------
class ItemizedClaimData(BaseModel):
    description: str = Field(description="Item description (medicine/procedure/test/consultation)")
    amount: float = Field(description="Amount billed for this item in INR")
    category: str = Field(description="Category: medicine, procedure, diagnostic_test, consultation")
    is_covered: bool = Field(description="True if covered by policy")
    exclusion_reason: str = Field(description="If not covered, why. Otherwise 'None'")
    is_medically_necessary: bool = Field(description="True if clinically justified")
    medical_necessity_reason: str = Field(description="Why it is/isn't necessary")

# ---------------------------------------------------------
# 1. Gemini Extraction Output Schema
# (We force Gemini to output this exact structure)
# ---------------------------------------------------------
class ExtractedClaimData(BaseModel):
    patient_name: str = Field(description="Name of the patient on the document")
    treatment_date: str = Field(description="Date of treatment in YYYY-MM-DD format")
    doctor_name: str = Field(description="Name of the treating doctor")
    doctor_reg_no: str = Field(description="Doctor's medical registration number")
    diagnosis: str = Field(description="Primary diagnosis or reason for visit")
    is_treatment_excluded: bool = Field(default=False, description="True if the treatment matches an exclusion")
    exclusion_reason: str = Field(default="None")
    # Itemized breakdown instead of simple lists
    itemized_claims: List[ItemizedClaimData] = Field(description="Line-by-line breakdown of all billed items with individual coverage assessment")
    requires_pre_auth: bool = Field(default=False, description="True if procedure needs pre-auth")
    missing_pre_auth: bool = Field(default=False, description="True if pre-auth is missing")
    total_billed_amount: float = Field(description="Total amount billed in INR")
    overall_medically_necessary: bool = Field(description="Is the overall treatment medically justified")
    medical_necessity_reasoning: str = Field(description="Overall clinical assessment")

# ---------------------------------------------------------
# 2. API Input Schema
# (What the frontend/Postman sends to our FastAPI route)
# ---------------------------------------------------------
class ClaimSubmission(BaseModel):
    member_id: str
    claim_amount: float
    cashless_request: bool = False
    hospital_name: Optional[str] = None
    # Note: Files (images/pdfs) will be handled via FastAPI UploadFile, not Pydantic

# ---------------------------------------------------------
# 3. Final Adjudication Output Schema
# (Matches the exact assignment requirement format)
# ---------------------------------------------------------
class AdjudicationResponse(BaseModel):
    claim_id: str
    decision: Literal["APPROVED", "REJECTED", "PARTIAL", "MANUAL_REVIEW"]
    approved_amount: float
    rejection_reasons: List[str]
    confidence_score: float
    notes: str
    next_steps: str
    cashless_approved: bool = False
    network_discount: float = 0.0