package model

import (
	"encoding/json"
	"fmt"
	"time"

	"gorm.io/gorm"
)

// DashboardApp represents a dashboard application configuration.
// Reference: Chatwoot app/models/dashboard_app.rb — P2B M12 spec
//
// A DashboardApp is a custom dashboard widget configuration that can be
// embedded as an iframe in the GoChat dashboard. Each app belongs to an
// account and optionally to a specific user (personal dashboards).
//
// Content format: JSON array of iframe configurations, e.g.:
//   [{"type": "frame", "url": "https://example.com/widget"}]
//
// Validation rules (per Chatwoot):
//   - content must be a JSON array (empty array allowed)
//   - each element must have type="frame" and url (http/https URI)
type DashboardApp struct {
	ID          uint           `gorm:"primaryKey;autoIncrement" json:"id"`
	AccountID   uint           `gorm:"not null;index" json:"account_id"`
	UserID      *uint          `gorm:"index" json:"user_id,omitempty"` // optional: per-user dashboard
	Title       string         `gorm:"size:255;not null" json:"title"`
	Description string         `gorm:"type:text" json:"description,omitempty"`
	Icon        string         `gorm:"size:255" json:"icon,omitempty"`   // icon URL or icon name
	URL         string         `gorm:"size:512" json:"url,omitempty"`     // primary iframe URL
	Kind        string         `gorm:"size:100;default:'frame'" json:"kind"` // frame, link
	Content     json.RawMessage `gorm:"type:json;serializer:json;default:'[]'" json:"content"` // iframe config array
	Active      *bool          `gorm:"default:true;not null" json:"active"`
	CreatedAt   time.Time      `gorm:"autoCreateTime" json:"created_at"`
	UpdatedAt   time.Time      `gorm:"autoUpdateTime" json:"updated_at"`
	DeletedAt   gorm.DeletedAt `gorm:"index" json:"deleted_at,omitempty"`

	// Relations
	Account *Account `gorm:"foreignKey:AccountID" json:"account,omitempty"`
	User    *User    `gorm:"foreignKey:UserID" json:"user,omitempty"`
}

func (DashboardApp) TableName() string { return "dashboard_apps" }

// BoolPtr returns a pointer to the given bool value.
// Useful for setting *bool fields like Active where false must be
// distinguishable from "not set" (nil) to avoid GORM zero-value skipping.
func BoolPtr(b bool) *bool { return &b }

// DashboardWidget represents a single widget/iframe within a DashboardApp's content.
// This is an in-memory structure used for widget CRUD — not a separate DB table.
// Widgets are stored as elements in the DashboardApp.Content jsonb array.
type DashboardWidget struct {
	Type string `json:"type"` // must be "frame"
	URL  string `json:"url"`  // must be http/https URI
	ID   string `json:"id,omitempty"` // optional client-assigned widget ID
	Name string `json:"name,omitempty"` // optional widget display name
}

// ValidateContent checks that content is a valid JSON array of iframe configs.
// Returns nil if valid, or an error describing what's wrong.
// Per Chatwoot M12 spec:
//   - content must be a JSON array
//   - each element must have type="frame" and url (http/https URI)
func ValidateContent(content json.RawMessage) error {
	if len(content) == 0 || string(content) == "" {
		return nil // empty content is OK (will be stored as [])
	}

	var widgets []DashboardWidget
	if err := json.Unmarshal(content, &widgets); err != nil {
		return fmt.Errorf("content must be a JSON array: %w", err)
	}

	for i, w := range widgets {
		if w.Type != "" && w.Type != "frame" {
			return fmt.Errorf("widget[%d].type must be 'frame', got '%s'", i, w.Type)
		}
		if w.URL != "" && !IsValidHTTPURL(w.URL) {
			return fmt.Errorf("widget[%d].url must be http/https URI, got '%s'", i, w.URL)
		}
	}
	return nil
}

// IsValidHTTPURL checks if a URL uses http or https scheme.
func IsValidHTTPURL(u string) bool {
	return (len(u) >= 7 && u[:7] == "http://") || (len(u) >= 8 && u[:8] == "https://")
}