namespace Distribution.Models
{
    public enum SchemeRuleType
    {
        BuyXGetY,
        SlabDiscount,
        FlatPercent,
        FreeBundle
    }

    public class Scheme : Template
    {
        public string Name { get; set; }
        public SchemeRuleType RuleType { get; set; }

        /// <summary>
        /// JSON payload for percentage-based rules only (SlabDiscount tiers, FlatPercent). Free-goods
        /// rules (BuyXGetY / FreeBundle) are structured fields/child rows below, not JSON, so they can
        /// be managed through their own CRUD endpoints instead of a hand-edited blob.
        /// </summary>
        public string? RuleConfig { get; set; }

        // ── BuyXGetY: trigger item/qty; shares FK_FreeItemId/FreeQty below as the payout. ──────────

        public Guid? FK_TriggerItemId { get; set; }
        public Item? TriggerItem { get; set; }
        public int? TriggerQty { get; set; }

        // ── Free-goods payout, used by both BuyXGetY and FreeBundle. ─────────────────────────────

        public Guid? FK_FreeItemId { get; set; }
        public Item? FreeItem { get; set; }
        public decimal? FreeQty { get; set; }

        /// <summary>Required component items for a FreeBundle scheme — managed via its own CRUD.</summary>
        public ICollection<SchemeBundleComponent> BundleComponents { get; set; } = [];

        public Guid? FK_RegionId { get; set; }
        public Region? Region { get; set; }

        /// <summary>Store segment this scheme applies to (Gold/Silver/Key Account/...); null = all segments.</summary>
        public string? EligibleSegment { get; set; }

        public DateTime DateRangeFrom { get; set; }
        public DateTime DateRangeTo { get; set; }

        /// <summary>
        /// When true, this scheme's discount is exempt from the per-role discount ceiling in
        /// 08_sales_agent_controls.md and stacks on top of it unconditionally.
        /// </summary>
        public bool AgentLimitExempt { get; set; }

        /// <summary>
        /// Manual baseline (expected sales with no scheme running) used by getSchemeROI. Per the
        /// open question in docs/17_promotions_schemes.md, this is entered at scheme creation
        /// rather than computed from a trailing-period average.
        /// </summary>
        public decimal? BaselineExpectedSales { get; set; }

        public ICollection<SchemeRedemption> Redemptions { get; set; } = [];
    }
}