// Copyright (C) 2016 The Android Open Source Project
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//      http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package adb

import (
	"errors"
	"net/url"
	"strings"

	"android.googlesource.com/platform/tools/gpu/client/bind"
	"android.googlesource.com/platform/tools/gpu/client/shell"
	"android.googlesource.com/platform/tools/gpu/framework/log"
)

// Devices returns the list of attached Android devices.
func Devices(ctx log.Context) ([]Device, error) {
	out, err := shell.Command(ADB, "devices").Call(ctx)
	if err != nil {
		return nil, err
	}
	return parseDevices(ctx, out)
}

func parseDevices(ctx log.Context, out string) ([]Device, error) {
	a := strings.SplitAfter(out, "List of devices attached")
	if len(a) != 2 {
		return nil, errors.New("Device list not returned")
	}
	lines := strings.Split(a[1], "\n")
	devices := make([]Device, 0, len(lines))
	for _, line := range lines {
		if strings.HasPrefix(line, "adb server version") && strings.HasSuffix(line, "killing...") {
			continue // adb server version (36) doesn't match this client (35); killing...
		}
		if strings.HasPrefix(line, "*") {
			continue // For example, "* daemon started successfully *"
		}
		fields := strings.Fields(line)
		switch len(fields) {
		case 0:
			continue
		case 2:
			device, err := bind.URL(ctx, &url.URL{Scheme: Scheme, Host: fields[0]})
			device.Info().Serial = fields[0]
			if err != nil {
				return nil, err
			}
			d := device.(*binding)
			status := fields[1]
			switch status {
			case "unknown":
				d.LastStatus = bind.Status_Unknown
			case "offline":
				d.LastStatus = bind.Status_Offline
			case "device":
				d.LastStatus = bind.Status_Online
			case "unauthorized":
				d.LastStatus = bind.Status_Unauthorized
			default:
				return nil, ctx.V("Value", status).AsError("Invalid status string")
			}
			devices = append(devices, d)
		default:
			return nil, errors.New("Could not parse device list")
		}
	}
	return devices, nil
}