cost_matrix.py

"""
cost_matrix.py
──────────────
Deterministic INR cost lookup table for GharScan.
No model hallucination here — pure market-rate data (Delhi/NCR, 2026).

Cost ranges sourced from: HouseYog, Comaron, UrbanCompany quoted rates,
and standard PWD schedule-of-rates for residential repairs.

Lower bound = Tier-2/3 city rates OR small affected area (< 2 sq ft)
Upper bound = Delhi/NCR metro rates OR large affected area (> 10 sq ft)
"""

from dataclasses import dataclass
from typing import Optional


@dataclass(frozen=True)
class CostEntry:
    cost_range_inr: str
    professional_type: str          # painter | mason | waterproofing_contractor | civil_engineer
    urgency_timeline: str           # next_renovation | within_6_months | within_1_month | this_week | immediately
    disclaimer: Optional[str] = None
    requires_engineer: bool = False


# ── Severity labels ────────────────────────────────────────────────────────────
SEVERITY_LABELS = {
    1: "Cosmetic",
    2: "Minor",
    3: "Moderate",
    4: "Serious",
    5: "Critical",
}

SEVERITY_COLORS = {
    1: "#22c55e",   # green
    2: "#84cc16",   # lime
    3: "#f59e0b",   # amber
    4: "#ef4444",   # red
    5: "#7f1d1d",   # dark red
}

# ── Main cost matrix ───────────────────────────────────────────────────────────
# Structure: COST_MATRIX[defect_type][severity_1_to_5] = CostEntry
COST_MATRIX: dict[str, dict[int, CostEntry]] = {

    "hairline_crack": {
        1: CostEntry("₹200–₹400",    "painter",          "next_renovation"),
        2: CostEntry("₹400–₹800",    "painter",          "next_renovation"),
        3: CostEntry("₹800–₹1,500",  "mason",            "within_6_months"),
        4: CostEntry("₹1,500–₹3,000","mason",            "within_1_month"),
        5: CostEntry("₹3,000–₹6,000","civil_engineer",   "this_week",
                     disclaimer="Multiple hairline cracks over large area — professional assessment strongly advised."),
    },

    "settlement_crack": {
        1: CostEntry("₹400–₹600",      "mason",          "next_renovation"),
        2: CostEntry("₹600–₹1,200",    "mason",          "within_6_months"),
        3: CostEntry("₹1,500–₹4,000",  "mason",          "within_6_months"),
        4: CostEntry("₹5,000–₹15,000", "civil_engineer", "within_1_month",
                     disclaimer="Severity 4 settlement cracks indicate significant differential movement. Professional structural assessment required before any repair.",
                     requires_engineer=True),
        5: CostEntry("Assessment required", "civil_engineer", "this_week",
                     disclaimer="URGENT: Wide or active settlement cracks may indicate ongoing foundation failure. Do not delay professional structural inspection.",
                     requires_engineer=True),
    },

    "structural_crack": {
        1: CostEntry("₹800–₹1,500",    "mason",          "within_6_months"),
        2: CostEntry("₹2,000–₹6,000",  "civil_engineer", "within_1_month"),
        3: CostEntry("₹8,000–₹25,000", "civil_engineer", "this_week",
                     requires_engineer=True),
        4: CostEntry("Assessment required", "civil_engineer", "this_week",
                     disclaimer="SERIOUS: Structural cracks at this severity require immediate professional inspection. Do not attempt DIY repairs.",
                     requires_engineer=True),
        5: CostEntry("Vacate and call engineer", "civil_engineer", "immediately",
                     disclaimer="CRITICAL STRUCTURAL RISK: This defect may compromise load-bearing capacity. Vacate the area immediately and contact a structural engineer.",
                     requires_engineer=True),
    },

    "water_seepage": {
        1: CostEntry("₹500–₹1,000",    "mason",                        "next_renovation"),
        2: CostEntry("₹1,500–₹4,000",  "waterproofing_contractor",     "within_6_months"),
        3: CostEntry("₹4,000–₹12,000", "waterproofing_contractor",     "within_1_month"),
        4: CostEntry("₹10,000–₹25,000","waterproofing_contractor",     "this_week",
                     disclaimer="Extensive seepage can weaken structural elements over time. Address before next monsoon season."),
        5: CostEntry("₹20,000–₹60,000","waterproofing_contractor",     "this_week",
                     disclaimer="Active water ingress at this scale indicates waterproofing system failure. Professional treatment of source (terrace/external wall) is required, not just surface patching.",
                     requires_engineer=True),
    },

    "efflorescence": {
        1: CostEntry("₹200–₹500",    "painter",                    "next_renovation"),
        2: CostEntry("₹500–₹1,500",  "mason",                      "next_renovation"),
        3: CostEntry("₹1,500–₹4,000","waterproofing_contractor",   "within_6_months"),
        4: CostEntry("₹4,000–₹10,000","waterproofing_contractor",  "within_1_month",
                     disclaimer="Heavy efflorescence indicates sustained moisture migration — treat the moisture source, not just the surface deposits."),
        5: CostEntry("₹10,000–₹20,000","waterproofing_contractor", "this_week",
                     disclaimer="Severe salt deposits with visible masonry deterioration. Source moisture must be identified and stopped before cosmetic repair."),
    },

    "spalling": {
        1: CostEntry("₹1,000–₹2,500",  "mason",          "within_6_months"),
        2: CostEntry("₹3,000–₹8,000",  "mason",          "within_1_month"),
        3: CostEntry("₹8,000–₹20,000", "civil_engineer", "this_week",
                     requires_engineer=True),
        4: CostEntry("Assessment required", "civil_engineer", "this_week",
                     disclaimer="SERIOUS: Concrete spalling with exposed reinforcement requires professional structural assessment — the scope of repair cannot be estimated from image alone.",
                     requires_engineer=True),
        5: CostEntry("Vacate area — engineer required", "civil_engineer", "immediately",
                     disclaimer="CRITICAL: Extensive spalling with exposed steel poses imminent risk of further concrete fall. Vacate the area below.",
                     requires_engineer=True),
    },

    "rebar_rust": {
        1: CostEntry("₹2,000–₹5,000",   "mason",          "within_1_month"),
        2: CostEntry("₹5,000–₹15,000",  "civil_engineer", "this_week",
                     requires_engineer=True),
        3: CostEntry("₹15,000–₹40,000", "civil_engineer", "this_week",
                     disclaimer="Rebar corrosion reduces structural capacity. Extent of rust along rebar length must be assessed by a structural engineer.",
                     requires_engineer=True),
        4: CostEntry("Assessment required", "civil_engineer", "immediately",
                     disclaimer="SERIOUS: Visible rebar corrosion with concrete delamination. Structural capacity may be significantly compromised.",
                     requires_engineer=True),
        5: CostEntry("Vacate area — urgent inspection", "civil_engineer", "immediately",
                     disclaimer="CRITICAL STRUCTURAL RISK: Extensive rebar corrosion threatens structural integrity. Immediate professional inspection mandatory.",
                     requires_engineer=True),
    },

    "plaster_delamination": {
        1: CostEntry("₹300–₹600",     "painter",  "next_renovation"),
        2: CostEntry("₹600–₹1,500",   "mason",    "next_renovation"),
        3: CostEntry("₹1,500–₹5,000", "mason",    "within_6_months"),
        4: CostEntry("₹5,000–₹12,000","mason",    "within_1_month",
                     disclaimer="Large-area delamination often indicates substrate moisture. Identify and treat moisture source before replastering."),
        5: CostEntry("₹12,000–₹25,000","mason",   "this_week",
                     disclaimer="Extensive plaster delamination over large wall area. Complete replastering required after identifying and treating root cause."),
    },

    "no_defect": {
        1: CostEntry("₹0 — No action needed", "none", "next_renovation"),
        2: CostEntry("₹0 — No action needed", "none", "next_renovation"),
        3: CostEntry("₹0 — No action needed", "none", "next_renovation"),
        4: CostEntry("₹0 — No action needed", "none", "next_renovation"),
        5: CostEntry("₹0 — No action needed", "none", "next_renovation"),
    },
}


# ── Professional display names ─────────────────────────────────────────────────
PROFESSIONAL_DISPLAY = {
    "painter":                  "Local Painter / Decorator",
    "mason":                    "Licensed Mason (Raj Mistri)",
    "waterproofing_contractor": "Waterproofing Contractor",
    "civil_engineer":           "Licensed Civil / Structural Engineer",
    "none":                     "No professional required",
}

TIMELINE_DISPLAY = {
    "next_renovation":  "At your next renovation",
    "within_6_months":  "Within 6 months",
    "within_1_month":   "Within 1 month",
    "this_week":        "This week",
    "immediately":      "IMMEDIATELY",
}


def get_cost_entry(defect_type: str, severity: int) -> CostEntry:
    """
    Primary lookup function.
    Returns CostEntry for a given defect_type × severity combination.
    Falls back to a safe default if defect type is not in matrix.
    """
    if defect_type not in COST_MATRIX:
        return CostEntry(
            cost_range_inr="Assessment required",
            professional_type="civil_engineer",
            urgency_timeline="within_1_month",
            disclaimer="Unrecognized defect type. Please consult a professional for assessment.",
            requires_engineer=True,
        )

    severity = max(1, min(5, int(severity)))   # Clamp to valid range
    return COST_MATRIX[defect_type][severity]


def build_cost_response(defect_type: str, severity: int) -> dict:
    """
    Returns a fully-structured dict ready for the frontend renderer.
    Includes display-friendly strings + disclaimer flag.
    """
    entry = get_cost_entry(defect_type, severity)

    return {
        "cost_range_inr":       entry.cost_range_inr,
        "professional_type":    entry.professional_type,
        "professional_display": PROFESSIONAL_DISPLAY.get(entry.professional_type, entry.professional_type),
        "urgency_timeline":     entry.urgency_timeline,
        "urgency_display":      TIMELINE_DISPLAY.get(entry.urgency_timeline, entry.urgency_timeline),
        "severity_label":       SEVERITY_LABELS.get(severity, "Unknown"),
        "severity_color":       SEVERITY_COLORS.get(severity, "#6b7280"),
        "requires_engineer":    entry.requires_engineer,
        "disclaimer":           entry.disclaimer,
        # Hard disclaimer for all Severity 4-5 (Watch-Out 2)
        "show_liability_banner": severity >= 4,
        "liability_text": (
            "⚠️ These are estimated market rates only. "
            "For Severity 4–5 defects, always obtain a professional site assessment "
            "before starting any repair work. GharScan is a triage tool, not a substitute "
            "for a licensed engineer or contractor."
        ) if severity >= 4 else None,
    }