package garagesrv

import (
	"bytes"
	"context"
	"fmt"
	"io"
	"os"
	"strconv"
	"text/template"

	"isle/garage"

	"dev.mediocregopher.com/mediocre-go-lib.git/mlog"
)

// GarageTomlData describes all fields needed for rendering a garage.toml
// file via this package's template.
type GarageTomlData struct {
	MetaPath string
	DataPath string

	RPCSecret  string
	AdminToken string
	DBEngine   DBEngine

	garage.LocalNode
	BootstrapPeers []garage.RemoteNode
}

var garageTomlTpl = template.Must(template.New("").Parse(`
metadata_dir = "{{ .MetaPath }}"
data_dir = "{{ .DataPath }}"
db_engine = "{{ .DBEngine }}"

replication_mode = "` + strconv.Itoa(garage.ReplicationFactor) + `"

rpc_secret = "{{ .RPCSecret }}"
rpc_bind_addr = "{{ .RPCAddr }}"
rpc_public_addr = "{{ .RPCAddr }}"

bootstrap_peers = [{{- range .BootstrapPeers }}
"{{ .RPCNodeAddr }}",
{{ end -}}]

[s3_api]
api_bind_addr = "{{ .S3APIAddr }}"
s3_region = "garage"

[admin]
api_bind_addr = "{{ .AdminAddr }}"
admin_token = "{{ .AdminToken }}"
`))

// RenderGarageToml renders a garage.toml using the given data into the writer.
func RenderGarageToml(into io.Writer, data GarageTomlData) error {
	return garageTomlTpl.Execute(into, data)
}

// WriteGarageTomlFile renders a garage.toml using the given data to a new file
// at the given path.
func WriteGarageTomlFile(
	ctx context.Context, logger *mlog.Logger, path string, data GarageTomlData,
) error {
	buf := new(bytes.Buffer)
	if err := garageTomlTpl.Execute(buf, data); err != nil {
		return fmt.Errorf("executing template: %w", err)
	}

	if err := os.WriteFile(path, buf.Bytes(), 0600); err != nil {
		return fmt.Errorf("writing file: %w", err)
	}

	return nil
}