package domain

import (
	"crypto/sha256"
	"encoding/hex"
	"encoding/json"
	"fmt"
	"regexp"
	"strings"
)

type Color struct {
	Code      string `json:"code"`
	Name      string `json:"name"`
	Hex       string `json:"hex"`
	Location  string `json:"location"`
	Available bool   `json:"available"`
}
type Pattern struct {
	ID         string    `json:"id"`
	Title      string    `json:"title"`
	Category   string    `json:"category"`
	Width      int       `json:"width"`
	Height     int       `json:"height"`
	Cells      []*string `json:"cells"`
	Colors     []Color   `json:"colors"`
	BeadCount  int       `json:"beadCount"`
	OwnerID    string    `json:"ownerId,omitempty"`
	Visibility string    `json:"visibility"`
	CreatedAt  string    `json:"createdAt"`
	StoreID    string    `json:"storeId"`
	Demo       bool      `json:"demo"`
}
type User struct {
	ID      string `json:"id"`
	Name    string `json:"name"`
	Role    string `json:"role"`
	StoreID string `json:"storeId"`
}
type Store struct {
	ID            string `json:"id"`
	Name          string `json:"name"`
	Address       string `json:"address"`
	Hours         string `json:"hours"`
	Notice        string `json:"notice"`
	LocalBaseURL  string `json:"localBaseUrl"`
	PublicBaseURL string `json:"publicBaseUrl"`
}
type Table struct {
	Code    string `json:"code"`
	Label   string `json:"label"`
	Enabled bool   `json:"enabled"`
}
type Visit struct {
	ID        string `json:"id"`
	StoreID   string `json:"storeId"`
	TableCode string `json:"tableCode"`
	Status    string `json:"status"`
}
type Request struct {
	ID        string `json:"id"`
	StoreID   string `json:"storeId"`
	UserID    string `json:"userId"`
	TableCode string `json:"tableCode"`
	Kind      string `json:"kind"`
	Note      string `json:"note"`
	Status    string `json:"status"`
	PatternID string `json:"patternId,omitempty"`
	CreatedAt string `json:"createdAt"`
	UpdatedAt string `json:"updatedAt"`
}

var hexColor = regexp.MustCompile(`^#[0-9a-fA-F]{6}$`)

func ValidateColors(cs []Color) error {
	seen := map[string]bool{}
	if len(cs) == 0 || len(cs) > 512 {
		return fmt.Errorf("色板需包含 1–512 色")
	}
	for _, c := range cs {
		if strings.TrimSpace(c.Code) == "" || len(c.Code) > 32 || seen[c.Code] || !hexColor.MatchString(c.Hex) {
			return fmt.Errorf("色号重复或颜色格式错误")
		}
		seen[c.Code] = true
	}
	return nil
}
func (p *Pattern) Validate() error {
	if strings.TrimSpace(p.Title) == "" || len(p.Title) > 200 || p.Width < 1 || p.Height < 1 || p.Width > 200 || p.Height > 200 || len(p.Cells) != p.Width*p.Height {
		return fmt.Errorf("图纸名称或尺寸无效（最大 200×200）")
	}
	if p.Visibility != "public" && p.Visibility != "private" {
		return fmt.Errorf("可见性无效")
	}
	if err := ValidateColors(p.Colors); err != nil {
		return err
	}
	cs := map[string]bool{}
	for _, c := range p.Colors {
		cs[c.Code] = true
	}
	p.BeadCount = 0
	for _, c := range p.Cells {
		if c != nil {
			if !cs[*c] {
				return fmt.Errorf("网格含未知色号")
			}
			p.BeadCount++
		}
	}
	return nil
}
func Transition(role, old, next string, own bool) bool {
	if role == "admin" || role == "staff" {
		return old == "pending" && next == "accepted" || old == "accepted" && next == "completed"
	}
	return own && old == "pending" && next == "cancelled"
}
func Fingerprint(kind, note, pattern string) string {
	b, _ := json.Marshal([]string{kind, note, pattern})
	h := sha256.Sum256(b)
	return hex.EncodeToString(h[:])
}
func CanRead(p Pattern, u User) bool {
	return p.Visibility == "public" || p.OwnerID == u.ID && u.ID != "" || (u.Role == "admin" || u.Role == "staff") && p.StoreID == u.StoreID
}