package repository

import (
	"context"
	"encoding/json"

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

// ScaleListItem is a published 探索测试.
type ScaleListItem struct {
	Slug        string `json:"slug"`
	Title       string `json:"title"`
	Description string `json:"description"`
}

// ScaleQuestion is one item in a scale.
type ScaleQuestion struct {
	ID   uuid.UUID       `json:"id"`
	Sort int             `json:"sort"`
	Body json.RawMessage `json:"body"`
}

// ScaleDetail is scale + questions.
type ScaleDetail struct {
	Slug        string          `json:"slug"`
	Title       string          `json:"title"`
	Description string          `json:"description"`
	Questions   []ScaleQuestion `json:"questions"`
}

// ScaleResultRow stored result.
type ScaleResultRow struct {
	ID        uuid.UUID       `json:"id"`
	ScaleSlug string          `json:"scale_slug"`
	Result    json.RawMessage `json:"result"`
}

// ScaleRepo loads scales and results.
type ScaleRepo struct {
	Pool *pgxpool.Pool
}

// ListPublished returns published scales.
func (r *ScaleRepo) ListPublished(ctx context.Context) ([]ScaleListItem, error) {
	rows, err := r.Pool.Query(ctx, `
		SELECT slug, title, description FROM scales
		WHERE status='published' AND deleted_at IS NULL ORDER BY created_at`)
	if err != nil {
		return nil, err
	}
	defer rows.Close()
	var out []ScaleListItem
	for rows.Next() {
		var it ScaleListItem
		if err := rows.Scan(&it.Slug, &it.Title, &it.Description); err != nil {
			return nil, err
		}
		out = append(out, it)
	}
	return out, rows.Err()
}

// GetBySlug loads scale with questions.
func (r *ScaleRepo) GetBySlug(ctx context.Context, slug string) (*ScaleDetail, error) {
	d := &ScaleDetail{Slug: slug}
	var scaleID uuid.UUID
	err := r.Pool.QueryRow(ctx, `
		SELECT id, title, description FROM scales
		WHERE slug=$1 AND deleted_at IS NULL`, slug,
	).Scan(&scaleID, &d.Title, &d.Description)
	if err != nil {
		return nil, err
	}
	rows, err := r.Pool.Query(ctx, `
		SELECT id, sort, body FROM scale_questions
		WHERE scale_id=$1 AND deleted_at IS NULL ORDER BY sort`, scaleID)
	if err != nil {
		return nil, err
	}
	defer rows.Close()
	for rows.Next() {
		var q ScaleQuestion
		if err := rows.Scan(&q.ID, &q.Sort, &q.Body); err != nil {
			return nil, err
		}
		d.Questions = append(d.Questions, q)
	}
	return d, rows.Err()
}

// SaveResult stores scoring output.
func (r *ScaleRepo) SaveResult(ctx context.Context, userID, scaleID, profileID uuid.UUID, answers, result json.RawMessage) (uuid.UUID, error) {
	var id uuid.UUID
	err := r.Pool.QueryRow(ctx, `
		INSERT INTO scale_results(user_id, scale_id, profile_id, answers, result)
		VALUES ($1,$2,$3,$4,$5) RETURNING id`,
		userID, scaleID, profileID, answers, result,
	).Scan(&id)
	return id, err
}

// ScaleIDBySlug resolves id.
func (r *ScaleRepo) ScaleIDBySlug(ctx context.Context, slug string) (uuid.UUID, error) {
	var id uuid.UUID
	err := r.Pool.QueryRow(ctx, `
		SELECT id FROM scales WHERE slug=$1 AND deleted_at IS NULL`, slug).Scan(&id)
	return id, err
}