package apps

import (
	"regexp"
	"strings"
	"time"

	// This is line from GORM documentation that imports database dialect
	_ "github.com/jinzhu/gorm/dialects/sqlite"
)

// ValidationError is error that holds multiple validation error messages
type ValidationError struct {
	// List of validation errors
	// Example: ["phone number is too short", "email address is wrongly formated"]
	Errors []string
}

func (v ValidationError) Error() string {
	return strings.Join(v.Errors, "\n")
}

// Label holds metadata about the application
type Label struct {
	// Value of the label
	// Example: userid:1
	// Required: true
	Value string `json:"value"`
	AppID uint   `json:"-" gorm:"not null"`
}

// AppState contains info about runnint application, it's not saved in the database
type AppState struct {
	State           string  `json:"state"`
	CPUUsage        float64 `json:"cpu_usage"`    // in percents
	MemoryUsage     int     `json:"memory_usage"` // in MB
	DiskUsageBytes  int     `json:"disk_usage_bytes"`
	DiskUsageInodes int     `json:"disk_usage_inodes"`
}

// Apps is list of applications
type Apps []App

// App keeps info about hosted application
type App struct {
	// ID of the applicaton
	// Unique: true
	ID uint `gorm:"primary_key" json:"id"`
	// Datetime of creation
	CreatedAt time.Time `json:"created_at"`
	// Datetime of last update
	UpdatedAt time.Time `json:"updated_at"`
	// Datetime of deletion
	DeletedAt *time.Time `sql:"index" json:"deleted_at"`

	// Name of the application
	// Example: test_1234
	Name string `json:"name" gorm:"unique,index,not_null"`
	// SSH port where the application will be available
	// Unique: true
	// Example: 10001
	SSHPort int `json:"ssh_port"`
	// HTTP port where the application will be available
	// Unique: true
	// Example: 10002
	HTTPPort int `json:"http_port"`
	// Runtime image
	Image string `json:"image"`
	// Number of CPUs ticks assigned, 100 means one CPU, 200 are two
	CPU int `json:"cpu"` // percentage, 200 means two CPU
	// Memory limit in MB
	Memory int `json:"memory"` // Limit in MB
	// Custom labels
	Labels []Label `json:"labels" gorm:"foreignkey:AppID"` // username:cx or user_id:1

	// Current status of the application (underlaying container)
	State string `json:"state"`
	// CPU usage in percents
	CPUUsage float64 `json:"cpu_usage"` // in percents
	// Memory usage in bytes
	MemoryUsage int `json:"memory_usage"` // in B
	// Disk usage in bytes
	DiskUsageBytes int `json:"disk_usage_bytes"`
	// Disk usage in inodes
	DiskUsageInodes int `json:"disk_usage_inodes"`

	// This is not store in the database but used in create request when the app suppose to be created from an existing snapshot
	Snapshot string `json:"snapshot" gorm:"-"`
}

// Validate do basic checks of the struct values
func (a *App) Validate() []string {
	var errors []string

	nameRegExp := regexp.MustCompile(`^[a-z0-9_\-]{3,48}$`)
	if !nameRegExp.MatchString(a.Name) {
		errors = append(errors, "name can contain only characters, numbers and underscores and has to be between 3 and 48 characters")
	}

	if a.SSHPort < 0 && a.SSHPort > 65536 {
		errors = append(errors, "SSH port has to be between 0 and 65536, where 0 means disabled")
	}

	if a.HTTPPort < 1 && a.HTTPPort > 65536 {
		errors = append(errors, "HTTP port has to be between 1 and 65536")
	}

	if a.Image == "" {
		errors = append(errors, "image cannot be empty")
	}

	if a.CPU < 10 && a.CPU > 800 {
		errors = append(errors, "CPU value has be between 10 and 800")
	}

	if a.Memory < 32 && a.Memory > 16384 {
		errors = append(errors, "Memory value has be between 32 and 16384")
	}

	return errors
}