package preferences

import (
	"context"
	"time"

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

// допустимые значения (для валидации)
var AllowedDrinks = map[string]bool{
	"beer": true, "wine": true, "whiskey": true, "vodka": true,
	"cocktail": true, "rum": true, "gin": true, "tequila": true,
	"cider": true, "champagne": true, "non_alcoholic": true,
}

var AllowedActivities = map[string]bool{
	"walk": true, "dinner": true, "bar": true, "cafe": true,
	"travel": true, "movie": true, "concert": true, "sport": true,
	"cooking": true, "gaming": true, "reading": true, "other": true,
}

var AllowedPurposes = map[string]bool{
	"chat": true, "drink": true, "walk": true, "dinner": true,
	"travel": true, "relationship": true, "friendship": true, "other": true,
}

type Prefs struct {
	UserID     uuid.UUID `json:"user_id"`
	Drinks     []string  `json:"drinks"`
	Activities []string  `json:"activities"`
	Purposes   []string  `json:"purposes"`
	Language   string    `json:"language"`
	UpdatedAt  time.Time `json:"updated_at"`
}

type Repo struct {
	pool *pgxpool.Pool
}

func NewRepo(pool *pgxpool.Pool) *Repo {
	return &Repo{pool: pool}
}

func (r *Repo) Get(ctx context.Context, userID uuid.UUID) (*Prefs, error) {
	p := &Prefs{UserID: userID, Drinks: []string{}, Activities: []string{}, Purposes: []string{}, Language: "ru"}
	err := r.pool.QueryRow(ctx, `
		SELECT drinks, activities, purposes, COALESCE(language, 'ru'), updated_at
		FROM user_preferences WHERE user_id=$1`, userID,
	).Scan(&p.Drinks, &p.Activities, &p.Purposes, &p.Language, &p.UpdatedAt)
	if err != nil {
		// no row = defaults
		p.UpdatedAt = time.Now()
		return p, nil
	}
	return p, nil
}

func (r *Repo) Upsert(ctx context.Context, p *Prefs) error {
	_, err := r.pool.Exec(ctx, `
		INSERT INTO user_preferences (user_id, drinks, activities, purposes, language, updated_at)
		VALUES ($1, $2, $3, $4, $5, NOW())
		ON CONFLICT (user_id) DO UPDATE
		SET drinks = EXCLUDED.drinks,
		    activities = EXCLUDED.activities,
		    purposes = EXCLUDED.purposes,
		    language = EXCLUDED.language,
		    updated_at = NOW()`,
		p.UserID, p.Drinks, p.Activities, p.Purposes, p.Language,
	)
	return err
}

func (r *Repo) Validate(values []string, allowed map[string]bool) []string {
	out := make([]string, 0, len(values))
	seen := make(map[string]bool)
	for _, v := range values {
		v = trimLower(v)
		if v == "" || seen[v] {
			continue
		}
		if allowed[v] {
			out = append(out, v)
			seen[v] = true
		}
	}
	return out
}

func trimLower(s string) string {
	out := []rune{}
	for _, r := range s {
		if r >= 'A' && r <= 'Z' {
			r = r + 32
		}
		out = append(out, r)
	}
	return string(out)
}