// Copyright 2015 The go-python Authors.  All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package main

import (
	"fmt"
	"log"

	"github.com/gonuts/commander"
	"github.com/gonuts/flag"
)

func gopyMakeCmdGen() *commander.Command {
	cmd := &commander.Command{
		Run:       gopyRunCmdGen,
		UsageLine: "gen <go-package-name> [other-go-package...]",
		Short:     "generate (C)Python language bindings for Go",
		Long: `
gen generates (C)Python language bindings for Go package(s).

ex:
 $ gopy gen [options] <go-package-name> [other-go-package...]
 $ gopy gen github.com/go-python/gopy/_examples/hi
`,
		Flag: *flag.NewFlagSet("gopy-gen", flag.ExitOnError),
	}

	cmd.Flag.String("vm", "python", "path to python interpreter")
	cmd.Flag.String("output", "", "output directory for bindings")
	cmd.Flag.String("name", "", "name of output package (otherwise name of first package is used)")
	return cmd
}

func gopyRunCmdGen(cmdr *commander.Command, args []string) error {
	var err error

	if len(args) != 1 {
		log.Printf("expect a fully qualified go package name as argument\n")
		return fmt.Errorf(
			"gopy-gen: expect a fully qualified go package name as argument",
		)
	}

	cmdstr := argStr()

	var (
		odir = cmdr.Flag.Lookup("output").Value.Get().(string)
		vm   = cmdr.Flag.Lookup("vm").Value.Get().(string)
		name = cmdr.Flag.Lookup("name").Value.Get().(string)
	)

	if vm == "" {
		vm = "python"
	}

	for _, path := range args {
		pkg, err := newPackage(path)
		if name == "" {
			name = pkg.Name()
		}
		if err != nil {
			return fmt.Errorf("gopy-gen: go/build.Import failed with path=%q: %v", path, err)
		}
	}

	err = genPkg(odir, name, cmdstr, vm)
	if err != nil {
		return err
	}

	return err
}