SNS型投資詐欺・ロマンス詐欺（年間被害1,272億円超）の手口と見分け方：著名人の偽広告とLINEグループの罠

#![forbid(unsafe_code)]

#[derive(Debug, Clone, Copy)]
pub struct InvestmentSolicitationTelemetry {
    pub uses_line_group_or_dm_mentor: bool,
    pub deposit_account_differs_from_broker_name: bool,
    pub demands_upfront_tax_or_fee_for_withdrawal: bool,
    pub promised_daily_yield_percent: f64,
    pub domain_age_days: u32,
}

#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub enum ScamVerdict {
    ConfirmedAdvanceFeeExitScam,      // Demands upfront tax/deposit to unlock withdrawal
    ConfirmedMuleAccountFraud,        // Deposit destination is an unrelated corp/individual account
    HighRiskPigButcheringPattern,     // LINE group + unrealistic daily compounding or new domain
    NoImmediateStructuralRedFlag,
}

/// Evaluates an investment solicitation against hard regulatory and structural invariants.
#[inline]
pub fn evaluate_investment_solicitation(
    t: &InvestmentSolicitationTelemetry,
) -> ScamVerdict {
    // Hard Invariant 1: Legitimate brokers deduct withholding tax internally; they NEVER require upfront transfer to withdraw
    if t.demands_upfront_tax_or_fee_for_withdrawal {
        return ScamVerdict::ConfirmedAdvanceFeeExitScam;
    }
    // Hard Invariant 2: Client funds must go to a segregated trust account matching the licensed broker
    if t.deposit_account_differs_from_broker_name {
        return ScamVerdict::ConfirmedMuleAccountFraud;
    }
    // Hard Invariant 3: Daily compounding >= 1.0%/day implies (1.01)^250 > 1200%/year + LINE group solicitation
    if t.uses_line_group_or_dm_mentor
        || t.promised_daily_yield_percent >= 1.0
        || t.domain_age_days < 90
    {
        return ScamVerdict::HighRiskPigButcheringPattern;
    }
    ScamVerdict::NoImmediateStructuralRedFlag
}