package garagesrv

import (
	"cmp"
	"context"
	"io"
	"slices"
	"strconv"
	"text/template"

	"isle/garage"
	"isle/toolkit"

	"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

	garage.LocalPeer
	BootstrapPeers []garage.RemotePeer
}

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

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

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

bootstrap_peers = [{{- range .BootstrapPeers }}
"{{ .RPCPeerAddr }}",
{{ 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, returning true if the file changed or didn't
// previously exist.
func WriteGarageTomlFile(
	ctx context.Context,
	logger *mlog.Logger,
	path string,
	data GarageTomlData,
) (
	bool, error,
) {
	slices.SortFunc(data.BootstrapPeers, func(i, j garage.RemotePeer) int {
		return cmp.Or(
			cmp.Compare(i.IP, j.IP),
			cmp.Compare(i.RPCPort, j.RPCPort),
		)
	})

	return toolkit.WriteFileCheckChanged(
		ctx, logger, path, 0600, func(w io.Writer) error {
			return garageTomlTpl.Execute(w, data)
		},
	)
}