package localdb

import (
	"database/sql/driver"
	"encoding/json"
	"errors"
	"time"
)

// AppSetting stores application settings in local SQLite
type AppSetting struct {
	Key       string    `gorm:"primaryKey" json:"key"`
	Value     string    `gorm:"not null" json:"value"`
	UpdatedAt time.Time `json:"updated_at"`
}

func (AppSetting) TableName() string {
	return "app_settings"
}

// LocalConfigItem represents an item in a configuration
type LocalConfigItem struct {
	LotName   string  `json:"lot_name"`
	Quantity  int     `json:"quantity"`
	UnitPrice float64 `json:"unit_price"`
}

// LocalConfigItems is a slice of LocalConfigItem that can be stored as JSON
type LocalConfigItems []LocalConfigItem

func (c LocalConfigItems) Value() (driver.Value, error) {
	return json.Marshal(c)
}

func (c *LocalConfigItems) Scan(value interface{}) error {
	if value == nil {
		*c = make(LocalConfigItems, 0)
		return nil
	}
	var bytes []byte
	switch v := value.(type) {
	case []byte:
		bytes = v
	case string:
		bytes = []byte(v)
	default:
		return errors.New("type assertion failed for LocalConfigItems")
	}
	return json.Unmarshal(bytes, c)
}

func (c LocalConfigItems) Total() float64 {
	var total float64
	for _, item := range c {
		total += item.UnitPrice * float64(item.Quantity)
	}
	return total
}

// LocalStringList is a JSON-encoded list of strings stored as TEXT in SQLite.
type LocalStringList []string

func (s LocalStringList) Value() (driver.Value, error) {
	return json.Marshal(s)
}

func (s *LocalStringList) Scan(value interface{}) error {
	if value == nil {
		*s = make(LocalStringList, 0)
		return nil
	}
	var bytes []byte
	switch v := value.(type) {
	case []byte:
		bytes = v
	case string:
		bytes = []byte(v)
	default:
		return errors.New("type assertion failed for LocalStringList")
	}
	return json.Unmarshal(bytes, s)
}

// LocalConfiguration stores configurations in local SQLite
type LocalConfiguration struct {
	ID               uint                        `gorm:"primaryKey;autoIncrement" json:"id"`
	UUID             string                      `gorm:"uniqueIndex;not null" json:"uuid"`
	ServerID         *uint                       `json:"server_id"` // ID on MariaDB server, NULL if local only
	ProjectUUID      *string                     `gorm:"index" json:"project_uuid,omitempty"`
	CurrentVersionID *string                     `gorm:"index" json:"current_version_id,omitempty"`
	IsActive         bool                        `gorm:"default:true;index" json:"is_active"`
	Name             string                      `gorm:"not null" json:"name"`
	Items            LocalConfigItems            `gorm:"type:text" json:"items"` // JSON stored as text in SQLite
	TotalPrice       *float64                    `json:"total_price"`
	CustomPrice      *float64                    `json:"custom_price"`
	Notes            string                      `json:"notes"`
	IsTemplate       bool                        `gorm:"default:false" json:"is_template"`
	ServerCount      int                         `gorm:"default:1" json:"server_count"`
	PricelistID      *uint                       `gorm:"index" json:"pricelist_id,omitempty"`
	OnlyInStock      bool                        `gorm:"default:false" json:"only_in_stock"`
	PriceUpdatedAt   *time.Time                  `gorm:"type:timestamp" json:"price_updated_at,omitempty"`
	CreatedAt        time.Time                   `json:"created_at"`
	UpdatedAt        time.Time                   `json:"updated_at"`
	SyncedAt         *time.Time                  `json:"synced_at"`
	SyncStatus       string                      `gorm:"default:'local'" json:"sync_status"` // 'local', 'synced', 'modified'
	OriginalUserID   uint                        `json:"original_user_id"`                   // UserID from MariaDB for reference
	OriginalUsername string                      `gorm:"not null;default:'';index" json:"original_username"`
	CurrentVersion   *LocalConfigurationVersion  `gorm:"foreignKey:CurrentVersionID;references:ID" json:"current_version,omitempty"`
	Versions         []LocalConfigurationVersion `gorm:"foreignKey:ConfigurationUUID;references:UUID" json:"versions,omitempty"`
}

func (LocalConfiguration) TableName() string {
	return "local_configurations"
}

type LocalProject struct {
	ID            uint       `gorm:"primaryKey;autoIncrement" json:"id"`
	UUID          string     `gorm:"uniqueIndex;not null" json:"uuid"`
	ServerID      *uint      `json:"server_id,omitempty"`
	OwnerUsername string     `gorm:"not null;index" json:"owner_username"`
	Name          string     `gorm:"not null" json:"name"`
	TrackerURL    string     `json:"tracker_url"`
	IsActive      bool       `gorm:"default:true;index" json:"is_active"`
	IsSystem      bool       `gorm:"default:false;index" json:"is_system"`
	CreatedAt     time.Time  `json:"created_at"`
	UpdatedAt     time.Time  `json:"updated_at"`
	SyncedAt      *time.Time `json:"synced_at,omitempty"`
	SyncStatus    string     `gorm:"default:'local'" json:"sync_status"` // local/synced/pending
}

func (LocalProject) TableName() string {
	return "local_projects"
}

// LocalConfigurationVersion stores immutable full snapshots for each configuration version
type LocalConfigurationVersion struct {
	ID                string              `gorm:"primaryKey" json:"id"`
	ConfigurationUUID string              `gorm:"not null;index:idx_lcv_config_created,priority:1;index:idx_lcv_config_version,priority:1;uniqueIndex:idx_lcv_config_version_unique,priority:1" json:"configuration_uuid"`
	VersionNo         int                 `gorm:"not null;index:idx_lcv_config_version,sort:desc,priority:2;uniqueIndex:idx_lcv_config_version_unique,priority:2" json:"version_no"`
	Data              string              `gorm:"type:text;not null" json:"data"`
	ChangeNote        *string             `json:"change_note,omitempty"`
	CreatedBy         *string             `json:"created_by,omitempty"`
	AppVersion        string              `gorm:"size:64" json:"app_version,omitempty"`
	CreatedAt         time.Time           `gorm:"not null;autoCreateTime;index:idx_lcv_config_created,sort:desc,priority:2" json:"created_at"`
	Configuration     *LocalConfiguration `gorm:"foreignKey:ConfigurationUUID;references:UUID" json:"configuration,omitempty"`
}

func (LocalConfigurationVersion) TableName() string {
	return "local_configuration_versions"
}

// LocalPricelist stores cached pricelists from server
type LocalPricelist struct {
	ID        uint      `gorm:"primaryKey;autoIncrement" json:"id"`
	ServerID  uint      `gorm:"not null;uniqueIndex" json:"server_id"` // ID on MariaDB server
	Source    string    `gorm:"not null;default:'estimate';index:idx_local_pricelists_source_created_at,priority:1" json:"source"`
	Version   string    `gorm:"not null;index" json:"version"`
	Name      string    `json:"name"`
	CreatedAt time.Time `gorm:"index:idx_local_pricelists_source_created_at,priority:2,sort:desc" json:"created_at"`
	SyncedAt  time.Time `json:"synced_at"`
	IsUsed    bool      `gorm:"default:false" json:"is_used"` // Used by any local configuration
}

func (LocalPricelist) TableName() string {
	return "local_pricelists"
}

// LocalPricelistItem stores pricelist items
type LocalPricelistItem struct {
	ID           uint            `gorm:"primaryKey;autoIncrement" json:"id"`
	PricelistID  uint            `gorm:"not null;index" json:"pricelist_id"`
	LotName      string          `gorm:"not null" json:"lot_name"`
	Price        float64         `gorm:"not null" json:"price"`
	AvailableQty *float64        `json:"available_qty,omitempty"`
	Partnumbers  LocalStringList `gorm:"type:text" json:"partnumbers,omitempty"`
}

func (LocalPricelistItem) TableName() string {
	return "local_pricelist_items"
}

// LocalComponent stores cached components for offline search
type LocalComponent struct {
	LotName        string    `gorm:"primaryKey" json:"lot_name"`
	LotDescription string    `json:"lot_description"`
	Category       string    `json:"category"`
	Model          string    `json:"model"`
	CurrentPrice   *float64  `json:"current_price"`
	SyncedAt       time.Time `json:"synced_at"`
}

func (LocalComponent) TableName() string {
	return "local_components"
}

// LocalRemoteMigrationApplied tracks remote SQLite migrations received from server and applied locally.
type LocalRemoteMigrationApplied struct {
	ID         string    `gorm:"primaryKey;size:128" json:"id"`
	Checksum   string    `gorm:"size:128;not null" json:"checksum"`
	AppVersion string    `gorm:"size:64" json:"app_version,omitempty"`
	AppliedAt  time.Time `gorm:"not null" json:"applied_at"`
}

func (LocalRemoteMigrationApplied) TableName() string {
	return "local_remote_migrations_applied"
}

// LocalSyncGuardState stores latest sync readiness decision for UI and preflight checks.
type LocalSyncGuardState struct {
	ID                    uint       `gorm:"primaryKey;autoIncrement" json:"id"`
	Status                string     `gorm:"size:32;not null;index" json:"status"` // ready|blocked|unknown
	ReasonCode            string     `gorm:"size:128" json:"reason_code,omitempty"`
	ReasonText            string     `gorm:"type:text" json:"reason_text,omitempty"`
	RequiredMinAppVersion *string    `gorm:"size:64" json:"required_min_app_version,omitempty"`
	LastCheckedAt         *time.Time `json:"last_checked_at,omitempty"`
	UpdatedAt             time.Time  `json:"updated_at"`
}

func (LocalSyncGuardState) TableName() string {
	return "local_sync_guard_state"
}

// PendingChange stores changes that need to be synced to the server
type PendingChange struct {
	ID         int64     `gorm:"primaryKey;autoIncrement" json:"id"`
	EntityType string    `gorm:"not null;index" json:"entity_type"` // "configuration", "project", "specification"
	EntityUUID string    `gorm:"not null;index" json:"entity_uuid"`
	Operation  string    `gorm:"not null" json:"operation"` // "create", "update", "rollback", "deactivate", "reactivate", "delete"
	Payload    string    `gorm:"type:text" json:"payload"`  // JSON snapshot of the entity
	CreatedAt  time.Time `gorm:"not null" json:"created_at"`
	Attempts   int       `gorm:"default:0" json:"attempts"` // Retry count for sync
	LastError  string    `gorm:"type:text" json:"last_error,omitempty"`
}

func (PendingChange) TableName() string {
	return "pending_changes"
}