package ctx

import (
	"errors"
	"path/filepath"

	"github.com/tal-tech/go-zero/tools/goctl/rpc/execx"
)

var moduleCheckErr = errors.New("the work directory must be found in the go mod or the $GOPATH")

type (
	ProjectContext struct {
		WorkDir string
		// Name is the root name of the project
		// eg: go-zero、greet
		Name string
		// Path identifies which module a project belongs to, which is module value if it's a go mod project,
		// or else it is the root name of the project, eg: github.com/tal-tech/go-zero、greet
		Path string
		// Dir is the path of the project, eg: /Users/keson/goland/go/go-zero、/Users/keson/go/src/greet
		Dir string
	}
)

// Prepare checks the project which module belongs to,and returns the path and module.
// workDir parameter is the directory of the source of generating code,
// where can be found the project path and the project module,
func Prepare(workDir string) (*ProjectContext, error) {
	ctx, err := background(workDir)
	if err == nil {
		return ctx, nil
	}

	name := filepath.Base(workDir)
	_, err = execx.Run("go mod init "+name, workDir)
	if err != nil {
		return nil, err
	}
	return background(workDir)
}

func background(workDir string) (*ProjectContext, error) {
	isGoMod, err := IsGoMod(workDir)
	if err != nil {
		return nil, err
	}

	if isGoMod {
		return projectFromGoMod(workDir)
	}
	return projectFromGoPath(workDir)
}