package contracts

import (
	"embed"
	"encoding/json"
	"fmt"
	"path"
	"strings"
)

// Files contains pinned upstream schemas and the active local contract versions.
// Runtime code never reads a checkout or resolves schema refs online.
//
//go:embed upstream local/v0.1 local/v0.2 local/v0.3 local/v0.4 local/*.json
var Files embed.FS

const SourceCommit = "v1"

// ReadCurrent reads the sole active project-local contract, with no fallback
// to a historical bundle if a name is missing or invalid.
func ReadCurrent(name string) ([]byte, error) {
	switch name {
	case "config-read.schema.json", "task-discovery.schema.json", "mq.schema.json", "mq-topology.json", "manifest.json":
		return Files.ReadFile(path.Join("local", name))
	default:
		return nil, fmt.Errorf("invalid current contract %q", name)
	}
}

func ReadLocal(version, name string) ([]byte, error) {
	if (version != "v0.1" && version != "v0.2" && version != "v0.3" && version != "v0.4") || name == "" || path.Base(name) != name || !strings.HasSuffix(name, ".schema.json") {
		return nil, fmt.Errorf("invalid project-local schema %q/%q", version, name)
	}
	return Files.ReadFile(path.Join("local", version, name))
}

func Read(name string) ([]byte, error) {
	return Files.ReadFile(path.Join("upstream", SourceCommit, name))
}

func ReadJSON(name string, dst any) error {
	data, err := Read(name)
	if err != nil {
		return fmt.Errorf("read contract %s: %w", name, err)
	}
	if err := json.Unmarshal(data, dst); err != nil {
		return fmt.Errorf("decode contract %s: %w", name, err)
	}
	return nil
}