package events

import (
	"context"
	"time"

	"github.com/pkg/errors"
)

// EventerType ...
type EventerType int

const (
	// LogFile indicates the event logger will be a logfile
	LogFile EventerType = iota
	// Journald indicates journald should be used to log events
	Journald EventerType = iota
	// Null is a no-op events logger. It does not read or write events.
	Null EventerType = iota
)

// Event describes the attributes of a libpod event
type Event struct {
	// ContainerExitCode is for storing the exit code of a container which can
	// be used for "internal" event notification
	ContainerExitCode int `json:",omitempty"`
	// ID can be for the container, image, volume, etc
	ID string `json:",omitempty"`
	// Image used where applicable
	Image string `json:",omitempty"`
	// Name where applicable
	Name string `json:",omitempty"`
	// Status describes the event that occurred
	Status Status
	// Time the event occurred
	Time time.Time
	// Type of event that occurred
	Type Type
}

// EventerOptions describe options that need to be passed to create
// an eventer
type EventerOptions struct {
	// EventerType describes whether to use journald or a file
	EventerType string
	// LogFilePath is the path to where the log file should reside if using
	// the file logger
	LogFilePath string
}

// Eventer is the interface for journald or file event logging
type Eventer interface {
	// Write an event to a backend
	Write(event Event) error
	// Read an event from the backend
	Read(ctx context.Context, options ReadOptions) error
	// String returns the type of event logger
	String() string
}

// ReadOptions describe the attributes needed to read event logs
type ReadOptions struct {
	// EventChannel is the comm path back to user
	EventChannel chan *Event
	// Filters are key/value pairs that describe to limit output
	Filters []string
	// FromStart means you start reading from the start of the logs
	FromStart bool
	// Since reads "since" the given time
	Since string
	// Stream is follow
	Stream bool
	// Until reads "until" the given time
	Until string
}

// Type of event that occurred (container, volume, image, pod, etc)
type Type string

// Status describes the actual event action (stop, start, create, kill)
type Status string

const (
	// If you add or subtract any values to the following lists, make sure you also update
	// the switch statements below and the enums for EventType or EventStatus in the
	// varlink description file.

	// Container - event is related to containers
	Container Type = "container"
	// Image - event is related to images
	Image Type = "image"
	// Pod - event is related to pods
	Pod Type = "pod"
	// System - event is related to Podman whole and not to any specific
	// container/pod/image/volume
	System Type = "system"
	// Volume - event is related to volumes
	Volume Type = "volume"

	// Attach ...
	Attach Status = "attach"
	// AutoUpdate ...
	AutoUpdate Status = "auto-update"
	// Checkpoint ...
	Checkpoint Status = "checkpoint"
	// Cleanup ...
	Cleanup Status = "cleanup"
	// Commit ...
	Commit Status = "commit"
	// Create ...
	Create Status = "create"
	// Exec ...
	Exec Status = "exec"
	// Exited indicates that a container's process died
	Exited Status = "died"
	// Export ...
	Export Status = "export"
	// History ...
	History Status = "history"
	// Import ...
	Import Status = "import"
	// Init ...
	Init Status = "init"
	// Kill ...
	Kill Status = "kill"
	// LoadFromArchive ...
	LoadFromArchive Status = "loadfromarchive"
	// Mount ...
	Mount Status = "mount"
	// Pause ...
	Pause Status = "pause"
	// Prune ...
	Prune Status = "prune"
	// Pull ...
	Pull Status = "pull"
	// Push ...
	Push Status = "push"
	// Refresh indicates that the system refreshed the state after a
	// reboot.
	Refresh Status = "refresh"
	// Remove ...
	Remove Status = "remove"
	// Renumber indicates that lock numbers were reallocated at user
	// request.
	Renumber Status = "renumber"
	// Restart indicates the target was restarted via an API call.
	Restart Status = "restart"
	// Restore ...
	Restore Status = "restore"
	// Save ...
	Save Status = "save"
	// Start ...
	Start Status = "start"
	// Stop ...
	Stop Status = "stop"
	// Sync ...
	Sync Status = "sync"
	// Tag ...
	Tag Status = "tag"
	// Unmount ...
	Unmount Status = "unmount"
	// Unpause ...
	Unpause Status = "unpause"
	// Untag ...
	Untag Status = "untag"
)

// EventFilter for filtering events
type EventFilter func(*Event) bool

var (
	// ErrEventTypeBlank indicates the event log found something done by podman
	// but it isn't likely an event
	ErrEventTypeBlank = errors.New("event type blank")

	// ErrEventNotFound indicates that the event was not found in the event log
	ErrEventNotFound = errors.New("unable to find event")
)