package command

import (
	"fmt"
	"strings"

	"github.com/hashicorp/consul/command/flags"
	"github.com/posener/complete"
)

type OperatorAutopilotSetCommand struct {
	Meta
}

func (c *OperatorAutopilotSetCommand) AutocompleteFlags() complete.Flags {
	return mergeAutocompleteFlags(c.Meta.AutocompleteFlags(FlagSetClient),
		complete.Flags{
			"-cleanup-dead-servers":      complete.PredictAnything,
			"-max-trailing-logs":         complete.PredictAnything,
			"-last-contact-threshold":    complete.PredictAnything,
			"-server-stabilization-time": complete.PredictAnything,
			"-enable-redundancy-zones":   complete.PredictNothing,
			"-disable-upgrade-migration": complete.PredictNothing,
			"-enable-custom-upgrades":    complete.PredictNothing,
		})
}

func (c *OperatorAutopilotSetCommand) AutocompleteArgs() complete.Predictor {
	return complete.PredictNothing
}

func (c *OperatorAutopilotSetCommand) Name() string { return "operator autopilot set-config" }

func (c *OperatorAutopilotSetCommand) Run(args []string) int {
	var cleanupDeadServers flags.BoolValue
	var maxTrailingLogs flags.UintValue
	var lastContactThreshold flags.DurationValue
	var serverStabilizationTime flags.DurationValue
	var enableRedundancyZones flags.BoolValue
	var disableUpgradeMigration flags.BoolValue
	var enableCustomUpgrades flags.BoolValue

	f := c.Meta.FlagSet("autopilot", FlagSetClient)
	f.Usage = func() { c.Ui.Output(c.Help()) }

	f.Var(&cleanupDeadServers, "cleanup-dead-servers", "")
	f.Var(&maxTrailingLogs, "max-trailing-logs", "")
	f.Var(&lastContactThreshold, "last-contact-threshold", "")
	f.Var(&serverStabilizationTime, "server-stabilization-time", "")
	f.Var(&enableRedundancyZones, "enable-redundancy-zones", "")
	f.Var(&disableUpgradeMigration, "disable-upgrade-migration", "")
	f.Var(&enableCustomUpgrades, "enable-custom-upgrades", "")

	if err := f.Parse(args); err != nil {
		c.Ui.Error(fmt.Sprintf("Failed to parse args: %v", err))
		return 1
	}

	// Set up a client.
	client, err := c.Meta.Client()
	if err != nil {
		c.Ui.Error(fmt.Sprintf("Error initializing client: %s", err))
		return 1
	}

	// Fetch the current configuration.
	operator := client.Operator()
	conf, _, err := operator.AutopilotGetConfiguration(nil)
	if err != nil {
		c.Ui.Error(fmt.Sprintf("Error querying for Autopilot configuration: %s", err))
		return 1
	}

	// Update the config values based on the set flags.
	cleanupDeadServers.Merge(&conf.CleanupDeadServers)
	enableRedundancyZones.Merge(&conf.EnableRedundancyZones)
	disableUpgradeMigration.Merge(&conf.DisableUpgradeMigration)
	enableRedundancyZones.Merge(&conf.EnableCustomUpgrades)

	trailing := uint(conf.MaxTrailingLogs)
	maxTrailingLogs.Merge(&trailing)
	conf.MaxTrailingLogs = uint64(trailing)
	lastContactThreshold.Merge(&conf.LastContactThreshold)
	serverStabilizationTime.Merge(&conf.ServerStabilizationTime)

	// Check-and-set the new configuration.
	result, _, err := operator.AutopilotCASConfiguration(conf, nil)
	if err != nil {
		c.Ui.Error(fmt.Sprintf("Error setting Autopilot configuration: %s", err))
		return 1
	}
	if result {
		c.Ui.Output("Configuration updated!")
		return 0
	}
	c.Ui.Output("Configuration could not be atomically updated, please try again")
	return 1
}

func (c *OperatorAutopilotSetCommand) Synopsis() string {
	return "Modify the current Autopilot configuration"
}

func (c *OperatorAutopilotSetCommand) Help() string {
	helpText := `
Usage: nomad operator autopilot set-config [options]

  Modifies the current Autopilot configuration.

General Options:

  ` + generalOptionsUsage() + `

Set Config Options:

  -cleanup-dead-servers=[true|false]
     Controls whether Nomad will automatically remove dead servers when
     new ones are successfully added. Must be one of [true|false].

  -disable-upgrade-migration=[true|false]
     (Enterprise-only) Controls whether Nomad will avoid promoting
     new servers until it can perform a migration. Must be one of
     "true|false".

  -last-contact-threshold=200ms
     Controls the maximum amount of time a server can go without contact
     from the leader before being considered unhealthy. Must be a
     duration value such as "200ms".

  -max-trailing-logs=<value>
     Controls the maximum number of log entries that a server can trail
     the leader by before being considered unhealthy.

  -redundancy-zone-tag=<value>
     (Enterprise-only) Controls the node_meta tag name used for
     separating servers into different redundancy zones.

  -server-stabilization-time=<10s>
     Controls the minimum amount of time a server must be stable in
     the 'healthy' state before being added to the cluster. Only takes
     effect if all servers are running Raft protocol version 3 or
     higher. Must be a duration value such as "10s".

  -upgrade-version-tag=<value>
     (Enterprise-only) The node_meta tag to use for version info when
     performing upgrade migrations. If left blank, the Nomad version
     will be used.
`
	return strings.TrimSpace(helpText)
}