CREATE OR ALTER FUNCTION pricing.approval_logic(
    @target       numeric(20,5),
    @last_norm    numeric(20,5),
    @list_eff     numeric(20,5),
    @last_date    date,
    @floor_pct    numeric(10,5) = 0.05,
    @cap_last_pct numeric(10,5) = 1.00,
    @cap_list_pct numeric(10,5) = 1.00
)
RETURNS @ret TABLE (
    guidance_price  numeric(20,5),
    guidance_reason nvarchar(4000)
)
AS
BEGIN
    DECLARE
        @base_price     numeric(20,5),
        @after_floor    numeric(20,5),
        @after_cap_last numeric(20,5),
        @final_price    numeric(20,5),
        @reason         nvarchar(4000) = N'';

    -- no target → early return
    IF @target IS NULL
    BEGIN
        INSERT INTO @ret VALUES (NULL, N'No target price available');
        RETURN;
    END;

    -- start from target
    SET @base_price = @target;

    -- Step 1: floor vs last_norm (only if it raises price)
    SET @after_floor = @base_price;
    IF @last_norm IS NOT NULL AND @floor_pct > 0
        SET @after_floor = ROUND(
            CASE WHEN @base_price >= @last_norm*(1-@floor_pct)
                 THEN @base_price
                 ELSE @last_norm*(1-@floor_pct)
            END, 5);

    -- Step 2: cap vs last_norm (only if it lowers price)
    SET @after_cap_last = @after_floor;
    IF @last_norm IS NOT NULL
        SET @after_cap_last = ROUND(
            CASE WHEN @after_floor <= @last_norm*@cap_last_pct
                 THEN @after_floor
                 ELSE @last_norm*@cap_last_pct
            END, 5);

    -- Step 3: cap vs list_eff (only if it lowers price)
    SET @final_price = @after_cap_last;
    IF @list_eff IS NOT NULL
        SET @final_price = ROUND(
            CASE WHEN @after_cap_last <= @list_eff*@cap_list_pct
                 THEN @after_cap_last
                 ELSE @list_eff*@cap_list_pct
            END, 5);

    -- Build explanation
    IF @last_norm IS NULL AND @list_eff IS NULL
    BEGIN
        SET @reason = N'No prior sale or list; using target price';
    END
    ELSE
    BEGIN
        SET @reason = N'Using target price';

        -- mention floor only if it raised the price
        IF @last_norm IS NOT NULL AND @floor_pct > 0 AND @after_floor > @base_price
            SET @reason += N', floored to ' + FORMAT(@floor_pct*100, '0.##') + N'% below last price';

        -- mention last cap only if it lowered the price
        IF @last_norm IS NOT NULL AND @after_cap_last < @after_floor
            SET @reason += CASE WHEN @cap_last_pct = 1
                                THEN N', capped to not exceed last price'
                                ELSE N', capped to ' + FORMAT(@cap_last_pct*100,'0.##') + N'% of last price'
                           END;

        -- mention list cap only if it lowered the price
        IF @list_eff IS NOT NULL AND @final_price < @after_cap_last
            SET @reason += CASE WHEN @cap_list_pct = 1
                                THEN N', capped to not exceed list price'
                                ELSE N', capped to ' + FORMAT(@cap_list_pct*100,'0.##') + N'% of list price'
                           END;
    END;

    INSERT INTO @ret VALUES (@final_price, @reason);
    RETURN;
END;