package plugin

import (
	"reflect"

	"github.com/pkg/errors"
)

type Configuration struct {
	SentryUrl              string
	SentryOrganisationName string
	SentryAuthToken        string
	// Add your configuration fields here
}

// Clone shallow copies the Configuration. Your implementation may require a deep copy if
// your Configuration has reference types.
func (c *Configuration) Clone() *Configuration {
	var clone = *c
	return &clone
}

// GetConfiguration retrieves the active Configuration under lock, making it safe to use
// concurrently. The active Configuration may change underneath the client of this method, but
// the struct returned by this API call is considered immutable.
func (p *Plugin) GetConfiguration() *Configuration {
	p.configurationLock.RLock()
	defer p.configurationLock.RUnlock()

	if p.configuration == nil {
		return &Configuration{}
	}

	return p.configuration
}

// SetConfiguration replaces the active Configuration under lock.
//
// Do not call SetConfiguration while holding the configurationLock, as sync.Mutex is not
// reentrant. In particular, avoid using the plugin API entirely, as this may in turn trigger a
// hook back into the plugin. If that hook attempts to acquire this lock, a deadlock may occur.
//
// This method panics if SetConfiguration is called with the existing Configuration. This almost
// certainly means that the Configuration was modified without being cloned and may result in
// an unsafe access.
func (p *Plugin) SetConfiguration(configuration *Configuration) {
	p.configurationLock.Lock()
	defer p.configurationLock.Unlock()
	p.API.LogInfo("Setting configuration")

	if configuration != nil && p.configuration == configuration {
		// Ignore assignment if the Configuration struct is empty. Go will optimize the
		// allocation for same to point at the same memory address, breaking the check
		// above.
		if reflect.ValueOf(*configuration).NumField() == 0 {
			return
		}

		p.API.LogInfo("Panic in SetConfiguration")
		panic("SetConfiguration called with the existing Configuration")
	}

	p.configuration = configuration
}

// OnConfigurationChange is invoked when Configuration changes may have been made.
func (p *Plugin) OnConfigurationChange() error {
	p.API.LogInfo("OnConfigurationChange")
	var configuration = new(Configuration)
	// Load the public Configuration fields from the Mattermost server Configuration.
	err := p.API.LoadPluginConfiguration(configuration)
	if err == nil {
		p.SetConfiguration(configuration)
		return nil
	} else {
		return errors.Wrap(err, "failed to load plugin Configuration")
	}
}