package cli

import (
	"encoding/json"
	"fmt"
	"os"

	"github.com/spf13/cobra"
)

func newSchemaCmd(opts *options) *cobra.Command {
	var (
		kind string
		out  string
	)
	cmd := &cobra.Command{
		Use:   "schema",
		Short: "Write the merged JSON Schema (core plus extensions)",
		Long: `Schema writes the release or release package schema with every extension
in the config applied. This is the schema the Go types are generated from,
which is useful for debugging a config or validating data with other tools.`,
		Example: `  ocdsgen schema > release-schema.json
  ocdsgen schema --kind package -o release-package-schema.json`,
		Args: cobra.NoArgs,
		RunE: func(cmd *cobra.Command, _ []string) error {
			if kind != "release" && kind != "package" {
				return fmt.Errorf(`--kind must be "release" or "package", got %q`, kind)
			}
			cfg, g, err := opts.setup(cmd)
			if err != nil {
				return err
			}
			exts, err := g.Resolve(cfg.Extensions)
			if err != nil {
				return err
			}
			s, err := g.Merge(cfg, exts)
			if err != nil {
				return err
			}
			doc := s.Release
			if kind == "package" {
				doc = s.Package
			}
			b, err := json.MarshalIndent(doc, "", "  ")
			if err != nil {
				return err
			}
			b = append(b, '\n')

			if out == "-" {
				_, err = cmd.OutOrStdout().Write(b)
			} else {
				err = os.WriteFile(out, b, 0o644)
			}
			if err != nil {
				return err
			}
			return opts.finish(g)
		},
	}
	f := cmd.Flags()
	f.StringVar(&kind, "kind", "release", `which schema to write: "release" or "package"`)
	f.StringVarP(&out, "out", "o", "-", `output file, or "-" for stdout`)
	return cmd
}