package stackevents

import (
	"encoding/json"
	"time"

	"github.com/gophercloud/gophercloud"
	"github.com/gophercloud/gophercloud/pagination"
)

// Event represents a stack event.
type Event struct {
	// The name of the resource for which the event occurred.
	ResourceName string `json:"resource_name"`
	// The time the event occurred.
	Time time.Time `json:"-"`
	// The URLs to the event.
	Links []gophercloud.Link `json:"links"`
	// The logical ID of the stack resource.
	LogicalResourceID string `json:"logical_resource_id"`
	// The reason of the status of the event.
	ResourceStatusReason string `json:"resource_status_reason"`
	// The status of the event.
	ResourceStatus string `json:"resource_status"`
	// The physical ID of the stack resource.
	PhysicalResourceID string `json:"physical_resource_id"`
	// The event ID.
	ID string `json:"id"`
	// Properties of the stack resource.
	ResourceProperties map[string]interface{} `json:"resource_properties"`
}

func (r *Event) UnmarshalJSON(b []byte) error {
	type tmp Event
	var s struct {
		tmp
		Time string `json:"event_time"`
	}

	err := json.Unmarshal(b, &s)
	if err != nil {
		return err
	}

	*r = Event(s.tmp)

	if s.Time != "" {
		t, err := time.Parse(time.RFC3339, s.Time)
		if err != nil {
			t, err = time.Parse(gophercloud.RFC3339NoZ, s.Time)
			if err != nil {
				return err
			}
		}
		r.Time = t
	}

	return nil
}

// FindResult represents the result of a Find operation.
type FindResult struct {
	gophercloud.Result
}

// Extract returns a slice of Event objects and is called after a
// Find operation.
func (r FindResult) Extract() ([]Event, error) {
	var s struct {
		Events []Event `json:"events"`
	}
	err := r.ExtractInto(&s)
	return s.Events, err
}

// EventPage abstracts the raw results of making a List() request against the API.
// As OpenStack extensions may freely alter the response bodies of structures returned to the client, you may only safely access the
// data provided through the ExtractResources call.
type EventPage struct {
	pagination.MarkerPageBase
}

// IsEmpty returns true if a page contains no Server results.
func (r EventPage) IsEmpty() (bool, error) {
	if r.StatusCode == 204 {
		return true, nil
	}

	events, err := ExtractEvents(r)
	return len(events) == 0, err
}

// LastMarker returns the last stack ID in a ListResult.
func (r EventPage) LastMarker() (string, error) {
	events, err := ExtractEvents(r)
	if err != nil {
		return "", err
	}
	if len(events) == 0 {
		return "", nil
	}
	return events[len(events)-1].ID, nil
}

// ExtractEvents interprets the results of a single page from a List() call, producing a slice of Event entities.
func ExtractEvents(r pagination.Page) ([]Event, error) {
	var s struct {
		Events []Event `json:"events"`
	}
	err := (r.(EventPage)).ExtractInto(&s)
	return s.Events, err
}

// ExtractResourceEvents interprets the results of a single page from a
// ListResourceEvents() call, producing a slice of Event entities.
func ExtractResourceEvents(page pagination.Page) ([]Event, error) {
	return ExtractEvents(page)
}

// GetResult represents the result of a Get operation.
type GetResult struct {
	gophercloud.Result
}

// Extract returns a pointer to an Event object and is called after a
// Get operation.
func (r GetResult) Extract() (*Event, error) {
	var s struct {
		Event *Event `json:"event"`
	}
	err := r.ExtractInto(&s)
	return s.Event, err
}
