// SPDX-License-Identifier: EUPL-1.2

package api

import (
	"io"

	"gopkg.in/yaml.v3"

	"dappco.re/go/core"
	coreio "dappco.re/go/core/io"
	coreerr "dappco.re/go/core/log"
)

// ExportSpec generates the OpenAPI spec and writes it to w.
// Format must be "json" or "yaml".
func ExportSpec(w io.Writer, format string, builder *SpecBuilder, groups []RouteGroup) error {
	data, err := builder.Build(groups)
	if err != nil {
		return coreerr.E("ExportSpec", "build spec", err)
	}

	switch format {
	case "json":
		_, err = w.Write(data)
		return err
	case "yaml":
		// Unmarshal JSON then re-marshal as YAML.
		var obj any
		result := core.JSONUnmarshal(data, &obj)
		if !result.OK {
			return coreerr.E("ExportSpec", "unmarshal spec", result.Value.(error))
		}
		encoder := yaml.NewEncoder(w)
		encoder.SetIndent(2)
		if err := encoder.Encode(obj); err != nil {
			return coreerr.E("ExportSpec", "encode yaml", err)
		}
		return encoder.Close()
	default:
		return coreerr.E("ExportSpec", "unsupported format "+format+": use \"json\" or \"yaml\"", nil)
	}
}

// ExportSpecToFile writes the spec to the given path.
// The parent directory is created if it does not exist.
//
//	err := api.ExportSpecToFile("./docs/openapi.json", "json", builder, groups)
//	err := api.ExportSpecToFile("./docs/openapi.yaml", "yaml", builder, groups)
func ExportSpecToFile(path, format string, builder *SpecBuilder, groups []RouteGroup) error {
	if err := coreio.Local.EnsureDir(core.PathDir(path)); err != nil {
		return coreerr.E("ExportSpecToFile", "create directory", err)
	}
	writer, err := coreio.Local.Create(path)
	if err != nil {
		return coreerr.E("ExportSpecToFile", "create file", err)
	}
	defer writer.Close()
	return ExportSpec(writer, format, builder, groups)
}