package main

import (
	"context"
	"isle/bootstrap"
	"isle/daemon"
	"isle/garage"
	"fmt"
	"net"
	"path/filepath"
	"strconv"

	"code.betamike.com/micropelago/pmux/pmuxlib"
	"github.com/mediocregopher/mediocre-go-lib/v2/mctx"
	"github.com/mediocregopher/mediocre-go-lib/v2/mlog"
)

func garageAdminClientLogger(logger *mlog.Logger) *mlog.Logger {
	return logger.WithNamespace("garageAdminClient")
}

// newGarageAdminClient will return an AdminClient for a local garage instance,
// or it will _panic_ if there is no local instance configured.
func newGarageAdminClient(
	logger *mlog.Logger,
	hostBootstrap bootstrap.Bootstrap,
	daemonConfig daemon.Config,
) *garage.AdminClient {

	thisHost := hostBootstrap.ThisHost()

	return garage.NewAdminClient(
		net.JoinHostPort(
			thisHost.IP().String(),
			strconv.Itoa(daemonConfig.Storage.Allocations[0].AdminPort),
		),
		hostBootstrap.Garage.AdminToken,
		garageAdminClientLogger(logger),
	)
}

func waitForGarageAndNebula(
	ctx context.Context,
	logger *mlog.Logger,
	hostBootstrap bootstrap.Bootstrap,
	daemonConfig daemon.Config,
) error {

	if err := waitForNebula(ctx, hostBootstrap); err != nil {
		return fmt.Errorf("waiting for nebula to start: %w", err)
	}

	allocs := daemonConfig.Storage.Allocations

	// if this host doesn't have any allocations specified then fall back to
	// waiting for nebula
	if len(allocs) == 0 {
		return nil
	}

	adminClientLogger := garageAdminClientLogger(logger)

	for _, alloc := range allocs {

		adminAddr := net.JoinHostPort(
			hostBootstrap.ThisHost().IP().String(),
			strconv.Itoa(alloc.AdminPort),
		)

		adminClient := garage.NewAdminClient(
			adminAddr,
			hostBootstrap.Garage.AdminToken,
			adminClientLogger,
		)

		ctx := mctx.Annotate(ctx, "garageAdminAddr", adminAddr)
		logger.Debug(ctx, "wating for garage instance to start")

		if err := adminClient.Wait(ctx); err != nil {
			return fmt.Errorf("waiting for garage instance %q to start up: %w", adminAddr, err)
		}
	}

	return nil

}

// bootstrapGarageHostForAlloc returns the bootstrap.GarageHostInstance which
// corresponds with the given alloc from the daemon config. This will panic if
// no associated instance can be found.
//
// This assumes that coalesceDaemonConfigAndBootstrap has already been called.
func bootstrapGarageHostForAlloc(
	host bootstrap.Host,
	alloc daemon.ConfigStorageAllocation,
) bootstrap.GarageHostInstance {

	for _, inst := range host.Garage.Instances {
		if inst.RPCPort == alloc.RPCPort {
			return inst
		}
	}

	panic(fmt.Sprintf("could not find alloc %+v in the bootstrap data", alloc))
}

func garageWriteChildConfig(
	hostBootstrap bootstrap.Bootstrap,
	alloc daemon.ConfigStorageAllocation,
) (
	string, error,
) {

	thisHost := hostBootstrap.ThisHost()
	id := bootstrapGarageHostForAlloc(thisHost, alloc).ID

	peer := garage.LocalPeer{
		RemotePeer: garage.RemotePeer{
			ID:        id,
			IP:        thisHost.IP().String(),
			RPCPort:   alloc.RPCPort,
			S3APIPort: alloc.S3APIPort,
		},
		AdminPort: alloc.AdminPort,
	}

	garageTomlPath := filepath.Join(
		envRuntimeDirPath, fmt.Sprintf("garage-%d.toml", alloc.RPCPort),
	)

	err := garage.WriteGarageTomlFile(garageTomlPath, garage.GarageTomlData{
		MetaPath: alloc.MetaPath,
		DataPath: alloc.DataPath,

		RPCSecret:  hostBootstrap.Garage.RPCSecret,
		AdminToken: hostBootstrap.Garage.AdminToken,

		RPCAddr:   peer.RPCAddr(),
		S3APIAddr: peer.S3APIAddr(),
		AdminAddr: peer.AdminAddr(),

		BootstrapPeers: hostBootstrap.GarageRPCPeerAddrs(),
	})

	if err != nil {
		return "", fmt.Errorf("creating garage.toml file at %q: %w", garageTomlPath, err)
	}

	return garageTomlPath, nil
}

func garagePmuxProcConfigs(
	hostBootstrap bootstrap.Bootstrap,
	daemonConfig daemon.Config,
) (
	[]pmuxlib.ProcessConfig, error,
) {

	var pmuxProcConfigs []pmuxlib.ProcessConfig

	for _, alloc := range daemonConfig.Storage.Allocations {

		childConfigPath, err := garageWriteChildConfig(hostBootstrap, alloc)

		if err != nil {
			return nil, fmt.Errorf("writing child config file for alloc %+v: %w", alloc, err)
		}

		pmuxProcConfigs = append(pmuxProcConfigs, pmuxlib.ProcessConfig{
			Name: fmt.Sprintf("garage-%d", alloc.RPCPort),
			Cmd:  binPath("garage"),
			Args: []string{"-c", childConfigPath, "server"},
			StartAfterFunc: func(ctx context.Context) error {
				return waitForNebula(ctx, hostBootstrap)
			},
		})
	}

	return pmuxProcConfigs, nil
}

func garageInitializeGlobalBucket(
	ctx context.Context,
	logger *mlog.Logger,
	hostBootstrap bootstrap.Bootstrap,
	daemonConfig daemon.Config,
) error {

	var (
		adminClient       = newGarageAdminClient(logger, hostBootstrap, daemonConfig)
		globalBucketCreds = hostBootstrap.Garage.GlobalBucketS3APICredentials
	)

	// first attempt to import the key
	err := adminClient.Do(ctx, nil, "POST", "/v0/key/import", map[string]string{
		"accessKeyId":     globalBucketCreds.ID,
		"secretAccessKey": globalBucketCreds.Secret,
		"name":            "shared-global-bucket-key",
	})

	if err != nil {
		return fmt.Errorf("importing global bucket key into garage: %w", err)
	}

	// create global bucket
	err = adminClient.Do(ctx, nil, "POST", "/v0/bucket", map[string]string{
		"globalAlias": garage.GlobalBucket,
	})

	if err != nil {
		return fmt.Errorf("creating global bucket: %w", err)
	}

	// retrieve newly created bucket's id
	var getBucketRes struct {
		ID string `json:"id"`
	}

	err = adminClient.Do(
		ctx, &getBucketRes,
		"GET", "/v0/bucket?globalAlias="+garage.GlobalBucket, nil,
	)

	if err != nil {
		return fmt.Errorf("fetching global bucket id: %w", err)
	}

	// allow shared global bucket key to perform all operations
	err = adminClient.Do(ctx, nil, "POST", "/v0/bucket/allow", map[string]interface{}{
		"bucketId":    getBucketRes.ID,
		"accessKeyId": globalBucketCreds.ID,
		"permissions": map[string]bool{
			"read":  true,
			"write": true,
		},
	})

	if err != nil {
		return fmt.Errorf("granting permissions to shared global bucket key: %w", err)
	}

	return nil
}

func garageApplyLayout(
	ctx context.Context,
	logger *mlog.Logger,
	hostBootstrap bootstrap.Bootstrap,
	daemonConfig daemon.Config,
) error {

	var (
		adminClient = newGarageAdminClient(logger, hostBootstrap, daemonConfig)
		thisHost    = hostBootstrap.ThisHost()
		hostName    = thisHost.Name
		allocs      = daemonConfig.Storage.Allocations
	)

	type peerLayout struct {
		Capacity int      `json:"capacity"`
		Zone     string   `json:"zone"`
		Tags     []string `json:"tags"`
	}

	{
		clusterLayout := map[string]peerLayout{}

		for _, alloc := range allocs {

			id := bootstrapGarageHostForAlloc(thisHost, alloc).ID

			zone := hostName
			if alloc.Zone != "" {
				zone = alloc.Zone
			}

			clusterLayout[id] = peerLayout{
				Capacity: alloc.Capacity,
				Zone:     zone,
				Tags:     []string{},
			}
		}

		err := adminClient.Do(ctx, nil, "POST", "/v0/layout", clusterLayout)
		if err != nil {
			return fmt.Errorf("staging layout changes: %w", err)
		}
	}

	var clusterLayout struct {
		Version           int                   `json:"version"`
		StagedRoleChanges map[string]peerLayout `json:"stagedRoleChanges"`
	}

	if err := adminClient.Do(ctx, &clusterLayout, "GET", "/v0/layout", nil); err != nil {
		return fmt.Errorf("retrieving staged layout change: %w", err)
	}

	if len(clusterLayout.StagedRoleChanges) == 0 {
		return nil
	}

	applyClusterLayout := struct {
		Version int `json:"version"`
	}{
		Version: clusterLayout.Version + 1,
	}

	err := adminClient.Do(ctx, nil, "POST", "/v0/layout/apply", applyClusterLayout)
	if err != nil {
		return fmt.Errorf("applying new layout (new version:%d): %w", applyClusterLayout.Version, err)
	}

	return nil
}