package model

// NotificationSetting represents per-user per-account notification preferences.
// Reference: Chatwoot app/models/notification_setting.rb
//
// Uses bitmask flags for email_flags and push_flags columns.
// Chatwoot uses FlagShihTzu gem for single-column multi-flag storage.
// FlagShihTzu bit positions: bit_value = 2^(enum_value - 1)
//
// Table name: notification_settings
//
//  id           uint   primaryKey autoIncrement
//  account_id   uint   not null; unique index with user_id
//  user_id      uint   not null; unique index with account_id
//  email_flags  int    default:0 not null; bitmask
//  push_flags   int    default:0 not null; bitmask
//  created_at   time
//  updated_at   time

type NotificationSetting struct {
	Base       `gorm:"embedded"`
	AccountID  uint `gorm:"not null;uniqueIndex:by_account_user"`
	UserID     uint `gorm:"not null;uniqueIndex:by_account_user"`
	EmailFlags int  `gorm:"default:0;not null"`
	PushFlags  int  `gorm:"default:0;not null"`
}

// TableName returns the database table name.
func (NotificationSetting) TableName() string { return "notification_settings" }

// Chatwoot NOTIFICATION_TYPES enum values and FlagShihTzu bit positions.
// Reference: Chatwoot Notification::NOTIFICATION_TYPES
// FlagShihTzu: has_flags key = "email_{type}" / "push_{type}", bit_value = 2^(enum_value - 1)
//
// Enum value → Flag name → Bit position → Bit value:
//   1 → conversation_creation           → bit 0 → 1
//   2 → conversation_assignment          → bit 1 → 2
//   3 → assigned_conversation_new_message → bit 2 → 4
//   4 → conversation_mention             → bit 3 → 8
//   5 → participating_conversation_new_message → bit 4 → 16
//   6 → sla_missed_first_response        → bit 5 → 32
//   7 → sla_missed_next_response         → bit 6 → 64
//   8 → sla_missed_resolution            → bit 7 → 128

const (
	// Email notification flags (bit values match Chatwoot FlagShihTzu)
	EmailFlagConversationCreation                 = 1  // 2^0
	EmailFlagConversationAssignment               = 2  // 2^1
	EmailFlagAssignedConversationNewMessage       = 4  // 2^2
	EmailFlagConversationMention                  = 8  // 2^3
	EmailFlagParticipatingConversationNewMessage  = 16 // 2^4
	EmailFlagSLAMissedFirstResponse               = 32 // 2^5
	EmailFlagSLAMissedNextResponse                = 64 // 2^6
	EmailFlagSLAMissedResolution                  = 128 // 2^7

	// Push notification flags (same bit values, separate column)
	PushFlagConversationCreation                 = 1
	PushFlagConversationAssignment               = 2
	PushFlagAssignedConversationNewMessage       = 4
	PushFlagConversationMention                  = 8
	PushFlagParticipatingConversationNewMessage  = 16
	PushFlagSLAMissedFirstResponse               = 32
	PushFlagSLAMissedNextResponse                = 64
	PushFlagSLAMissedResolution                  = 128
)

// AllEmailFlags returns the bitmask of all email notification types.
func AllEmailFlags() int {
	return EmailFlagConversationCreation |
		EmailFlagConversationAssignment |
		EmailFlagAssignedConversationNewMessage |
		EmailFlagConversationMention |
		EmailFlagParticipatingConversationNewMessage |
		EmailFlagSLAMissedFirstResponse |
		EmailFlagSLAMissedNextResponse |
		EmailFlagSLAMissedResolution
}

// AllPushFlags returns the bitmask of all push notification types.
func AllPushFlags() int {
	return PushFlagConversationCreation |
		PushFlagConversationAssignment |
		PushFlagAssignedConversationNewMessage |
		PushFlagConversationMention |
		PushFlagParticipatingConversationNewMessage |
		PushFlagSLAMissedFirstResponse |
		PushFlagSLAMissedNextResponse |
		PushFlagSLAMissedResolution
}

// AllEmailFlagNames returns all available email notification flag names.
// Matches Chatwoot FlagShihTzu generated flag names: "email_{type}".
func AllEmailFlagNames() []string {
	return []string{
		"email_conversation_creation",
		"email_conversation_assignment",
		"email_assigned_conversation_new_message",
		"email_conversation_mention",
		"email_participating_conversation_new_message",
		"email_sla_missed_first_response",
		"email_sla_missed_next_response",
		"email_sla_missed_resolution",
	}
}

// AllPushFlagNames returns all available push notification flag names.
// Matches Chatwoot FlagShihTzu generated flag names: "push_{type}".
func AllPushFlagNames() []string {
	return []string{
		"push_conversation_creation",
		"push_conversation_assignment",
		"push_assigned_conversation_new_message",
		"push_conversation_mention",
		"push_participating_conversation_new_message",
		"push_sla_missed_first_response",
		"push_sla_missed_next_response",
		"push_sla_missed_resolution",
	}
}

// Email flag name → bit value mapping for selected_email_flags parsing.
var emailFlagNameToValue = map[string]int{
	"email_conversation_creation":                EmailFlagConversationCreation,
	"email_conversation_assignment":              EmailFlagConversationAssignment,
	"email_assigned_conversation_new_message":    EmailFlagAssignedConversationNewMessage,
	"email_conversation_mention":                 EmailFlagConversationMention,
	"email_participating_conversation_new_message": EmailFlagParticipatingConversationNewMessage,
	"email_sla_missed_first_response":            EmailFlagSLAMissedFirstResponse,
	"email_sla_missed_next_response":             EmailFlagSLAMissedNextResponse,
	"email_sla_missed_resolution":                EmailFlagSLAMissedResolution,
}

// Push flag name → bit value mapping for selected_push_flags parsing.
var pushFlagNameToValue = map[string]int{
	"push_conversation_creation":                PushFlagConversationCreation,
	"push_conversation_assignment":              PushFlagConversationAssignment,
	"push_assigned_conversation_new_message":    PushFlagAssignedConversationNewMessage,
	"push_conversation_mention":                 PushFlagConversationMention,
	"push_participating_conversation_new_message": PushFlagParticipatingConversationNewMessage,
	"push_sla_missed_first_response":            PushFlagSLAMissedFirstResponse,
	"push_sla_missed_next_response":             PushFlagSLAMissedNextResponse,
	"push_sla_missed_resolution":                PushFlagSLAMissedResolution,
}

// Email bit value → flag name mapping.
var emailValueToFlagName = map[int]string{
	EmailFlagConversationCreation:                "email_conversation_creation",
	EmailFlagConversationAssignment:              "email_conversation_assignment",
	EmailFlagAssignedConversationNewMessage:      "email_assigned_conversation_new_message",
	EmailFlagConversationMention:                 "email_conversation_mention",
	EmailFlagParticipatingConversationNewMessage: "email_participating_conversation_new_message",
	EmailFlagSLAMissedFirstResponse:              "email_sla_missed_first_response",
	EmailFlagSLAMissedNextResponse:               "email_sla_missed_next_response",
	EmailFlagSLAMissedResolution:                 "email_sla_missed_resolution",
}

// Push bit value → flag name mapping.
var pushValueToFlagName = map[int]string{
	PushFlagConversationCreation:                "push_conversation_creation",
	PushFlagConversationAssignment:              "push_conversation_assignment",
	PushFlagAssignedConversationNewMessage:      "push_assigned_conversation_new_message",
	PushFlagConversationMention:                 "push_conversation_mention",
	PushFlagParticipatingConversationNewMessage: "push_participating_conversation_new_message",
	PushFlagSLAMissedFirstResponse:              "push_sla_missed_first_response",
	PushFlagSLAMissedNextResponse:               "push_sla_missed_next_response",
	PushFlagSLAMissedResolution:                 "push_sla_missed_resolution",
}

// HasEmailFlag checks if a specific email flag is enabled.
func (ns *NotificationSetting) HasEmailFlag(flag int) bool {
	return ns.EmailFlags&flag != 0
}

// HasPushFlag checks if a specific push flag is enabled.
func (ns *NotificationSetting) HasPushFlag(flag int) bool {
	return ns.PushFlags&flag != 0
}

// SetEmailFlagsFromNames sets email flags from a list of flag names.
// Reference: Chatwoot selected_email_flags (FlagShihTzu flag names like "email_conversation_creation")
func (ns *NotificationSetting) SetEmailFlagsFromNames(names []string) {
	ns.EmailFlags = 0
	for _, name := range names {
		if v, ok := emailFlagNameToValue[name]; ok {
			ns.EmailFlags |= v
		}
	}
}

// SetPushFlagsFromNames sets push flags from a list of flag names.
// Reference: Chatwoot selected_push_flags
func (ns *NotificationSetting) SetPushFlagsFromNames(names []string) {
	ns.PushFlags = 0
	for _, name := range names {
		if v, ok := pushFlagNameToValue[name]; ok {
			ns.PushFlags |= v
		}
	}
}

// SelectedEmailFlagNames returns the names of enabled email flags.
// Matches Chatwoot FlagShihTzu: returns "email_{type}" format names.
func (ns *NotificationSetting) SelectedEmailFlagNames() []string {
	names := []string{}
	for _, bitValue := range []int{
		EmailFlagConversationCreation,
		EmailFlagConversationAssignment,
		EmailFlagAssignedConversationNewMessage,
		EmailFlagConversationMention,
		EmailFlagParticipatingConversationNewMessage,
		EmailFlagSLAMissedFirstResponse,
		EmailFlagSLAMissedNextResponse,
		EmailFlagSLAMissedResolution,
	} {
		if ns.EmailFlags&bitValue != 0 {
			names = append(names, emailValueToFlagName[bitValue])
		}
	}
	return names
}

// SelectedPushFlagNames returns the names of enabled push flags.
// Matches Chatwoot FlagShihTzu: returns "push_{type}" format names.
func (ns *NotificationSetting) SelectedPushFlagNames() []string {
	names := []string{}
	for _, bitValue := range []int{
		PushFlagConversationCreation,
		PushFlagConversationAssignment,
		PushFlagAssignedConversationNewMessage,
		PushFlagConversationMention,
		PushFlagParticipatingConversationNewMessage,
		PushFlagSLAMissedFirstResponse,
		PushFlagSLAMissedNextResponse,
		PushFlagSLAMissedResolution,
	} {
		if ns.PushFlags&bitValue != 0 {
			names = append(names, pushValueToFlagName[bitValue])
		}
	}
	return names
}