package repository

import (
	"context"
	"errors"

	"github.com/google/uuid"
	"github.com/jackc/pgx/v5"
)

// MembershipPlanAmountCents returns catalog price or fallback for membership plans.
func (r *ReportRepo) MembershipPlanAmountCents(ctx context.Context, plan string) (int, error) {
	var amount int
	var active bool
	err := r.Pool.QueryRow(ctx, `
		SELECT amount_cents, active FROM membership_plans WHERE code=$1`, plan,
	).Scan(&amount, &active)
	if errors.Is(err, pgx.ErrNoRows) {
		return membershipAmountFallback(plan), nil
	}
	if err != nil {
		return 0, err
	}
	if !active {
		return 0, errString("plan inactive")
	}
	return amount, nil
}

func membershipAmountFallback(plan string) int {
	switch plan {
	case "month":
		return 2500
	case "quarter":
		return 6800
	case "year":
		return 19800
	default:
		return 2500
	}
}

// MembershipPlanDurationDays returns catalog days or fallback.
func (r *ReportRepo) MembershipPlanDurationDays(ctx context.Context, plan string) (int, error) {
	var days int
	var active bool
	err := r.Pool.QueryRow(ctx, `
		SELECT duration_days, active FROM membership_plans WHERE code=$1`, plan,
	).Scan(&days, &active)
	if errors.Is(err, pgx.ErrNoRows) {
		return membershipDaysFallback(plan), nil
	}
	if err != nil {
		return 0, err
	}
	if !active || days <= 0 {
		return membershipDaysFallback(plan), nil
	}
	return days, nil
}

func membershipDaysFallback(plan string) int {
	switch plan {
	case "month":
		return 31
	case "quarter":
		return 92
	case "year":
		return 366
	default:
		return 31
	}
}

// RedeemCode applies an unused redemption code to user membership.
func (r *ReportRepo) RedeemCode(ctx context.Context, userID uuid.UUID, rawCode string) (plan string, err error) {
	tx, err := r.Pool.Begin(ctx)
	if err != nil {
		return "", err
	}
	defer tx.Rollback(ctx)

	var codeID uuid.UUID
	var status string
	err = tx.QueryRow(ctx, `
		SELECT id, plan_code, status FROM redemption_codes
		WHERE code=$1 FOR UPDATE`, rawCode,
	).Scan(&codeID, &plan, &status)
	if errors.Is(err, pgx.ErrNoRows) {
		return "", errString("invalid code")
	}
	if err != nil {
		return "", err
	}
	if status != "unused" {
		return "", errString("code not redeemable")
	}
	days, err := r.MembershipPlanDurationDays(ctx, plan)
	if err != nil {
		return "", err
	}
	if _, err := tx.Exec(ctx, `
		UPDATE redemption_codes
		SET status='redeemed', redeemed_by=$2, redeemed_at=now()
		WHERE id=$1 AND status='unused'`, codeID, userID); err != nil {
		return "", err
	}
	if _, err := tx.Exec(ctx, `
		INSERT INTO memberships(user_id, plan, status, expires_at, ask_quota_left)
		VALUES ($1,$2,'active', now() + ($3 * interval '1 day'), 100)
		ON CONFLICT (user_id) DO UPDATE SET
			plan=EXCLUDED.plan, status='active',
			expires_at=(CASE
				WHEN memberships.expires_at IS NOT NULL AND memberships.expires_at > now()
				THEN memberships.expires_at ELSE now()
			END) + ($3 * interval '1 day'),
			ask_quota_left=100, updated_at=now()`,
		userID, plan, days); err != nil {
		return "", err
	}
	if err := tx.Commit(ctx); err != nil {
		return "", err
	}
	return plan, nil
}