package repository

import (
	"context"
	"errors"
	"strings"
	"time"

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

// FilterRuleRow is ContentSafety FilterRule persistence.
type FilterRuleRow struct {
	ID        uuid.UUID `json:"id"`
	Code      string    `json:"code"`
	Title     string    `json:"title"`
	Category  string    `json:"category"`
	Pattern   string    `json:"pattern"`
	Action    string    `json:"action"`
	Active    bool      `json:"active"`
	System    bool      `json:"system"`
	UpdatedAt time.Time `json:"updated_at"`
}

// FilterMatch is one evaluate hit.
type FilterMatch struct {
	Code     string `json:"code"`
	Title    string `json:"title"`
	Category string `json:"category"`
	Action   string `json:"action"`
}

// ListFilterRules returns active-first filter rules.
func (r *AdminRepo) ListFilterRules(ctx context.Context) ([]FilterRuleRow, error) {
	rows, err := r.Pool.Query(ctx, `
		SELECT id, code, title, category, pattern, action, active, system, updated_at
		FROM filter_rules
		ORDER BY active DESC, category ASC, code ASC LIMIT 500`)
	if err != nil {
		return nil, err
	}
	defer rows.Close()
	var out []FilterRuleRow
	for rows.Next() {
		var f FilterRuleRow
		if err := rows.Scan(
			&f.ID, &f.Code, &f.Title, &f.Category, &f.Pattern, &f.Action, &f.Active, &f.System, &f.UpdatedAt,
		); err != nil {
			return nil, err
		}
		out = append(out, f)
	}
	return out, rows.Err()
}

// GetFilterRule loads one rule by id.
func (r *AdminRepo) GetFilterRule(ctx context.Context, id uuid.UUID) (*FilterRuleRow, error) {
	var f FilterRuleRow
	err := r.Pool.QueryRow(ctx, `
		SELECT id, code, title, category, pattern, action, active, system, updated_at
		FROM filter_rules WHERE id=$1`, id,
	).Scan(&f.ID, &f.Code, &f.Title, &f.Category, &f.Pattern, &f.Action, &f.Active, &f.System, &f.UpdatedAt)
	if errors.Is(err, pgx.ErrNoRows) {
		return nil, err
	}
	if err != nil {
		return nil, err
	}
	return &f, nil
}

// EvaluateFilterRules runs simple substring match on active rules (ops preview).
func (r *AdminRepo) EvaluateFilterRules(ctx context.Context, text string) ([]FilterMatch, error) {
	rules, err := r.ListFilterRules(ctx)
	if err != nil {
		return nil, err
	}
	lower := strings.ToLower(text)
	var out []FilterMatch
	for _, rule := range rules {
		if !rule.Active || rule.Pattern == "" {
			continue
		}
		if strings.Contains(lower, strings.ToLower(rule.Pattern)) {
			out = append(out, FilterMatch{
				Code: rule.Code, Title: rule.Title, Category: rule.Category, Action: rule.Action,
			})
		}
	}
	if out == nil {
		out = []FilterMatch{}
	}
	return out, nil
}