import { PatientDataForRiskAssessment, RiskDetectionResult, RiskFactor } from "./types";
import { RISK_FACTORS, RISK_THRESHOLDS } from "./config";

function checkRedFlags(data: PatientDataForRiskAssessment): { isRedFlag: boolean; reasons: string[] } {
  const reasons: string[] = [];

  if (data.bloodPressureSystolic && data.bloodPressureDiastolic) {
    if (data.bloodPressureSystolic >= 160 || data.bloodPressureDiastolic >= 110) {
      reasons.push("Severely elevated blood pressure (≥160/110 mmHg)");
    }
  } else if (data.bloodPressureSystolic && data.bloodPressureSystolic >= 160) {
    reasons.push("Severely elevated systolic blood pressure (≥160 mmHg)");
  } else if (data.bloodPressureDiastolic && data.bloodPressureDiastolic >= 110) {
    reasons.push("Severely elevated diastolic blood pressure (≥110 mmHg)");
  }

  if (data.hasConvulsions) {
    reasons.push("Convulsions present");
  }

  if (data.hasLossOfConsciousness) {
    reasons.push("Loss of consciousness");
  }

  if (data.hasHeavyVaginalBleeding) {
    reasons.push("Heavy vaginal bleeding");
  }

  if (data.hasAbsentFetalMovement) {
    reasons.push("Absent fetal movement");
  }

  return { isRedFlag: reasons.length > 0, reasons };
}

function evaluateRiskFactors(data: PatientDataForRiskAssessment): {
  contributingFactors: RiskFactor[];
  totalScore: number;
  reasons: string[];
} {
  const contributingFactors: RiskFactor[] = [];
  const reasons: string[] = [];
  let totalScore = 0;

  if (data.age !== undefined && data.age >= 35) {
    const factor = RISK_FACTORS.find((f) => f.id === "advanced-maternal-age");
    if (factor) {
      contributingFactors.push(factor);
      reasons.push(factor.description);
      totalScore += factor.points;
    }
  } else if (data.age !== undefined && data.age < 18) {
    const factor = RISK_FACTORS.find((f) => f.id === "teen-pregnancy");
    if (factor) {
      contributingFactors.push(factor);
      reasons.push(factor.description);
      totalScore += factor.points;
    }
  }

  if (data.bmi !== undefined && data.bmi >= 35) {
    const factor = RISK_FACTORS.find((f) => f.id === "bmi-over-35");
    if (factor) {
      contributingFactors.push(factor);
      reasons.push(factor.description);
      totalScore += factor.points;
    }
  }

  if (data.parity !== undefined && data.parity >= 5) {
    const factor = RISK_FACTORS.find((f) => f.id === "grand-multiparity");
    if (factor) {
      contributingFactors.push(factor);
      reasons.push(factor.description);
      totalScore += factor.points;
    }
  }

  if (data.previousCaesareans && data.previousCaesareans > 0) {
    const factor = RISK_FACTORS.find((f) => f.id === "previous-caesarean");
    if (factor) {
      contributingFactors.push(factor);
      reasons.push(factor.description);
      totalScore += factor.points;
    }
  }

  if (data.previousStillbirths && data.previousStillbirths > 0) {
    const factor = RISK_FACTORS.find((f) => f.id === "previous-stillbirth");
    if (factor) {
      contributingFactors.push(factor);
      reasons.push(factor.description);
      totalScore += factor.points;
    }
  }

  if (data.previousIufd) {
    const factor = RISK_FACTORS.find((f) => f.id === "previous-iufd");
    if (factor) {
      contributingFactors.push(factor);
      reasons.push(factor.description);
      totalScore += factor.points;
    }
  }

  if (data.previousPreeclampsia) {
    const factor = RISK_FACTORS.find((f) => f.id === "previous-preeclampsia");
    if (factor) {
      contributingFactors.push(factor);
      reasons.push(factor.description);
      totalScore += factor.points;
    }
  }

  if (data.previousEclampsia) {
    const factor = RISK_FACTORS.find((f) => f.id === "previous-eclampsia");
    if (factor) {
      contributingFactors.push(factor);
      reasons.push(factor.description);
      totalScore += factor.points;
    }
  }

  if (data.gestationalHypertension) {
    const factor = RISK_FACTORS.find((f) => f.id === "gestational-hypertension");
    if (factor) {
      contributingFactors.push(factor);
      reasons.push(factor.description);
      totalScore += factor.points;
    }
  }

  if (data.chronicHypertension || data.chronicHypertensionBeforePregnancy) {
    const factor = RISK_FACTORS.find((f) => f.id === "chronic-hypertension");
    if (factor) {
      contributingFactors.push(factor);
      reasons.push(factor.description);
      totalScore += factor.points;
    }
  }

  if (data.diabetesMellitus) {
    const factor = RISK_FACTORS.find((f) => f.id === "diabetes-mellitus");
    if (factor) {
      contributingFactors.push(factor);
      reasons.push(factor.description);
      totalScore += factor.points;
    }
  }

  if (data.kidneyDisease) {
    const factor = RISK_FACTORS.find((f) => f.id === "kidney-disease");
    if (factor) {
      contributingFactors.push(factor);
      reasons.push(factor.description);
      totalScore += factor.points;
    }
  }

  if (data.heartDisease) {
    const factor = RISK_FACTORS.find((f) => f.id === "heart-disease");
    if (factor) {
      contributingFactors.push(factor);
      reasons.push(factor.description);
      totalScore += factor.points;
    }
  }

  if (data.previousPlacentalAbruption) {
    const factor = RISK_FACTORS.find((f) => f.id === "previous-placental-abruption");
    if (factor) {
      contributingFactors.push(factor);
      reasons.push(factor.description);
      totalScore += factor.points;
    }
  }

  if (data.previousPlacentaPrevia) {
    const factor = RISK_FACTORS.find((f) => f.id === "placenta-previa");
    if (factor) {
      contributingFactors.push(factor);
      reasons.push(factor.description);
      totalScore += factor.points;
    }
  }

  if (data.previousMultiplePregnancy) {
    const factor = RISK_FACTORS.find((f) => f.id === "twin-pregnancy");
    if (factor) {
      contributingFactors.push(factor);
      reasons.push(factor.description);
      totalScore += factor.points;
    }
  }

  if (data.previousGestationalDiabetes) {
    const factor = RISK_FACTORS.find((f) => f.id === "previous-gestational-diabetes");
    if (factor) {
      contributingFactors.push(factor);
      reasons.push(factor.description);
      totalScore += factor.points;
    }
  }

  if (data.familyPreeclampsia) {
    const factor = RISK_FACTORS.find((f) => f.id === "family-preeclampsia");
    if (factor) {
      contributingFactors.push(factor);
      reasons.push(factor.description);
      totalScore += factor.points;
    }
  }

  if (data.familyHypertension) {
    const factor = RISK_FACTORS.find((f) => f.id === "family-hypertension");
    if (factor) {
      contributingFactors.push(factor);
      reasons.push(factor.description);
      totalScore += factor.points;
    }
  }

  if (data.previousPretermBirth) {
    const factor = RISK_FACTORS.find((f) => f.id === "previous-preterm-birth");
    if (factor) {
      contributingFactors.push(factor);
      reasons.push(factor.description);
      totalScore += factor.points;
    }
  }

  if (data.previousLowBirthWeight) {
    const factor = RISK_FACTORS.find((f) => f.id === "previous-low-birth-weight");
    if (factor) {
      contributingFactors.push(factor);
      reasons.push(factor.description);
      totalScore += factor.points;
    }
  }

  if (data.previousPostpartumHemorrhage) {
    const factor = RISK_FACTORS.find((f) => f.id === "previous-postpartum-hemorrhage");
    if (factor) {
      contributingFactors.push(factor);
      reasons.push(factor.description);
      totalScore += factor.points;
    }
  }

  if (data.smokingStatus === "CURRENT") {
    const factor = RISK_FACTORS.find((f) => f.id === "current-smoking");
    if (factor) {
      contributingFactors.push(factor);
      reasons.push(factor.description);
      totalScore += factor.points;
    }
  }

  if (data.alcoholUse === "REGULAR") {
    const factor = RISK_FACTORS.find((f) => f.id === "current-alcohol");
    if (factor) {
      contributingFactors.push(factor);
      reasons.push(factor.description);
      totalScore += factor.points;
    }
  }

  return { contributingFactors, totalScore, reasons };
}

function calculateRiskLevel(score: number): "LOW" | "MODERATE" | "HIGH" | "EMERGENCY" {
  for (const threshold of RISK_THRESHOLDS) {
    if (threshold.maxPoints === null) {
      if (score >= threshold.minPoints) return threshold.level;
    } else {
      if (score >= threshold.minPoints && score <= threshold.maxPoints) {
        return threshold.level;
      }
    }
  }
  return "LOW";
}

function collectRecommendations(factors: RiskFactor[]): string[] {
  const recommendations = new Set<string>();
  factors.forEach((factor) => {
    factor.recommendations.forEach((rec) => recommendations.add(rec));
  });
  return Array.from(recommendations);
}

export function detectRisks(data: PatientDataForRiskAssessment): RiskDetectionResult {
  const { isRedFlag, reasons: redFlagReasons } = checkRedFlags(data);
  const { contributingFactors, totalScore, reasons: riskFactorReasons } = evaluateRiskFactors(data);
  let riskLevel = calculateRiskLevel(totalScore);
  const recommendations = collectRecommendations(contributingFactors);

  if (isRedFlag) {
    riskLevel = "EMERGENCY";
  }

  return {
    riskLevel,
    score: totalScore,
    reasons: isRedFlag ? redFlagReasons : riskFactorReasons,
    contributingFactors,
    recommendations,
    isRedFlag,
    redFlagReasons: isRedFlag ? redFlagReasons : undefined,
  };
}