package entrypoint

import (
	"context"
	crypticnet "cryptic-net"
	"cryptic-net/garage"
	"fmt"
	"net"
	"os"
	"path/filepath"
	"strconv"
	"time"

	"github.com/cryptic-io/pmux/pmuxlib"
)

func waitForGarageArgs(env *crypticnet.Env, args ...string) []string {

	thisHost := env.Bootstrap.ThisHost()
	allocs := env.ThisDaemon().Storage.Allocations

	if len(allocs) == 0 {
		return waitForNebulaArgs(env, args...)
	}

	var preArgs []string

	for _, alloc := range allocs {
		preArgs = append(
			preArgs,
			"wait-for",
			net.JoinHostPort(thisHost.Nebula.IP, strconv.Itoa(alloc.RPCPort)),
			"--",
		)
	}

	return append(preArgs, args...)
}

func garageWriteChildConf(
	env *crypticnet.Env,
	alloc crypticnet.DaemonYmlStorageAllocation,
) (
	string, error,
) {

	if err := os.MkdirAll(alloc.MetaPath, 0750); err != nil {
		return "", fmt.Errorf("making directory %q: %w", alloc.MetaPath, err)
	}

	thisHost := env.Bootstrap.ThisHost()

	peer := garage.Peer{
		IP:        thisHost.Nebula.IP,
		RPCPort:   alloc.RPCPort,
		S3APIPort: alloc.S3APIPort,
	}

	pubKey, privKey := peer.RPCPeerKey()

	nodeKeyPath := filepath.Join(alloc.MetaPath, "node_key")
	nodeKeyPubPath := filepath.Join(alloc.MetaPath, "node_keypub")

	if err := os.WriteFile(nodeKeyPath, privKey, 0400); err != nil {
		return "", fmt.Errorf("writing private key to %q: %w", nodeKeyPath, err)

	} else if err := os.WriteFile(nodeKeyPubPath, pubKey, 0440); err != nil {
		return "", fmt.Errorf("writing public key to %q: %w", nodeKeyPubPath, err)
	}

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

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

		RPCSecret:  env.Bootstrap.GarageRPCSecret,
		AdminToken: env.Bootstrap.GarageAdminToken,

		RPCAddr:   net.JoinHostPort(thisHost.Nebula.IP, strconv.Itoa(alloc.RPCPort)),
		APIAddr:   net.JoinHostPort(thisHost.Nebula.IP, strconv.Itoa(alloc.S3APIPort)),
		AdminAddr: net.JoinHostPort(thisHost.Nebula.IP, strconv.Itoa(alloc.AdminPort)),

		BootstrapPeers: env.Bootstrap.GarageRPCPeerAddrs(),
	})

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

	return garageTomlPath, nil
}

func garageChildrenPmuxProcConfigs(env *crypticnet.Env) ([]pmuxlib.ProcessConfig, error) {

	var pmuxProcConfigs []pmuxlib.ProcessConfig

	for _, alloc := range env.ThisDaemon().Storage.Allocations {

		childConfPath, err := garageWriteChildConf(env, 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:         "garage",
			Args:        []string{"-c", childConfPath, "server"},
			SigKillWait: 1 * time.Minute,
		})
	}

	return pmuxProcConfigs, nil
}

func garageApplyLayoutDiffPmuxProcConfig(env *crypticnet.Env) pmuxlib.ProcessConfig {
	return pmuxlib.ProcessConfig{
		Name:        "garage-apply-layout-diff",
		Cmd:         "bash",
		Args:        waitForGarageArgs(env, "bash", "garage-apply-layout-diff"),
		NoRestartOn: []int{0},
	}
}

func garageApplyLayout(
	ctx context.Context,
	adminClient *garage.AdminClient,
	hostName, ipStr string,
	allocs []crypticnet.DaemonYmlStorageAllocation,
) error {

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

	{
		clusterLayout := map[string]peerLayout{}

		for _, alloc := range allocs {

			peer := garage.Peer{
				IP:        ipStr,
				RPCPort:   alloc.RPCPort,
				S3APIPort: alloc.S3APIPort,
			}

			clusterLayout[peer.RPCPeerID()] = peerLayout{
				Capacity: alloc.Capacity / 100,
				Zone:     hostName,
			}
		}

		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
}