/*
NAME
  Config.go

DESCRIPTION
  See Readme.md

AUTHORS
  Saxon A. Nelson-Milton <saxon@ausocean.org>

LICENSE
  Config.go is Copyright (C) 2017-2018 the Australian Ocean Lab (AusOcean)

  It is free software: you can redistribute it and/or modify them
  under the terms of the GNU General Public License as published by the
  Free Software Foundation, either version 3 of the License, or (at your
  option) any later version.

  It is distributed in the hope that it will be useful, but WITHOUT
  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
 for more details.

  You should have received a copy of the GNU General Public License
  along with revid in gpl.txt.  If not, see http://www.gnu.org/licenses.
*/

package revid

import (
	"errors"

	"bitbucket.org/ausocean/utils/logger"
)

// Possible modes for raspivid --exposure parameter.
var ExposureModes = [...]string{
	"auto",
	"night",
	"nightpreview",
	"backlight",
	"spotlight",
	"sports",
	"snow",
	"beach",
	"verylong",
	"fixedfps",
	"antishake",
	"fireworks",
}

// Possible modes for raspivid --awb parameter.
var AutoWhiteBalanceModes = [...]string{
	"off",
	"auto",
	"sun",
	"cloud",
	"shade",
	"tungsten",
	"fluorescent",
	"incandescent",
	"flash",
	"horizon",
}

// Enums to define inputs, outputs and codecs.
const (
	// Indicates no option has been set.
	NothingDefined = iota

	// Input/Output.
	File

	// Inputs.
	Raspivid
	V4L

	// Outputs.
	RTMP
	RTP
	HTTP
	MPEGTS

	// Codecs.
	H264
	MJPEG
)

// Default config settings
const (
	defaultInput              = Raspivid
	defaultOutput             = HTTP
	defaultFrameRate          = 25
	defaultWidth              = 1280
	defaultHeight             = 720
	defaultIntraRefreshPeriod = 100
	defaultTimeout            = 0
	defaultQuantization       = 40
	defaultBitrate            = 400000
	defaultFramesPerClip      = 1
	httpFramesPerClip         = 560
	defaultInputCodec         = H264
	defaultVerbosity          = logger.Error
	defaultRtpAddr            = "localhost:6970"
	defaultBurstPeriod        = 10 // Seconds
	defaultRotation           = 0  // Degrees
	defaultBrightness         = 50
	defaultExposure           = "auto"
	defaultAutoWhiteBalance   = "auto"
)

// Config provides parameters relevant to a revid instance. A new config must
// be passed to the constructor. Default values for these fields are defined
// as consts above.
type Config struct {
	// LogLevel is the revid logging verbosity level.
	// Valid values are defined by enums from the logger package: logger.Debug,
	// logger.Info, logger.Warning logger.Error, logger.Fatal.
	LogLevel int8

	// Input defines the input data source.
	//
	// Valid values are defined by enums:
	// Raspivid:
	//		Read data from a Raspberry Pi Camera.
	// V4l:
	//		Read from webcam.
	// File:
	// 		Location must be specified in InputPath field.
	Input uint8

	// InputCodec defines the input codec we wish to use, and therefore define the
	// lexer for use in the pipeline. In most cases this defaults according to a
	// particular input. Both Raspivid and V4l use H264, but File input may use
	// H264 or MJPEG.
	InputCodec uint8

	// Outputs define the outputs we wish to output data too.
	//
	// Valid outputs are defined by enums:
	// File:
	// 		Location must be defined by the OutputPath field. MPEG-TS packetization
	//		is used.
	// Http:
	// 		Destination is defined by the sh field located in /etc/netsender.conf.
	// 		MPEGT-TS packetization is used.
	// Rtmp:
	// 		Destination URL must be defined in the RtmpUrl field. FLV packetization
	//		is used.
	// Rtp:
	// 		Destination is defined by RtpAddr field, otherwise it will default to
	//		localhost:6970. MPEGT-TS packetization is used.
	Outputs []uint8

	// Quantize specifies whether the input to revid will have constant or variable
	// bitrate.
	Quantize bool

	// FlipHorizonatla and FlipVertical specify whether video frames should be flipped.
	FlipHorizontal bool
	FlipVertical   bool

	FramesPerClip uint

	// RtmpUrl specifies the Rtmp output destination URL. This must be defined if
	// RTMP is to be used as an output.
	RtmpUrl            string
	Bitrate            uint
	OutputPath         string
	InputPath          string
	Height             uint
	Width              uint
	FrameRate          uint
	HttpAddress        string
	Quantization       uint
	IntraRefreshPeriod uint
	RtpAddress         string
	Logger             Logger
	SendRetry          bool
	BurstPeriod        uint
	Rotation           uint
	Brightness         uint
	Saturation         int
	Exposure           string
	AutoWhiteBalance   string
}

// Validate checks for any errors in the config fields and defaults settings
// if particular parameters have not been defined.
func (c *Config) Validate(r *Revid) error {
	switch c.LogLevel {
	case logger.Debug:
	case logger.Info:
	case logger.Warning:
	case logger.Error:
	case logger.Fatal:
	default:
		c.LogLevel = defaultVerbosity
		c.Logger.Log(logger.Info, pkg+"bad LogLevel mode defined, defaulting", "LogLevel", defaultVerbosity)
	}

	switch c.Input {
	case Raspivid, V4L, File:
	case NothingDefined:
		c.Logger.Log(logger.Info, pkg+"no input type defined, defaulting", "input", defaultInput)
		c.Input = defaultInput
	default:
		return errors.New("bad input type defined in config")
	}

	switch c.InputCodec {
	case H264:
		// FIXME(kortschak): This is not really what we want.
		// Configuration really needs to be rethought here.
		if c.Quantize && c.Quantization == 0 {
			c.Quantization = defaultQuantization
		}

		if (c.Bitrate > 0 && c.Quantize) || (c.Bitrate == 0 && !c.Quantize) {
			return errors.New("bad bitrate and quantization combination for H264 input")
		}

	case MJPEG:
		if c.Quantization > 0 || c.Bitrate == 0 {
			return errors.New("bad bitrate or quantization for mjpeg input")
		}

	case NothingDefined:
		c.Logger.Log(logger.Info, pkg+"no input codec defined, defaulting", "inputCodec", defaultInputCodec)
		c.InputCodec = defaultInputCodec
		c.Logger.Log(logger.Info, pkg+"defaulting quantization", "quantization", defaultQuantization)
		c.Quantization = defaultQuantization
	default:
		return errors.New("bad input codec defined in config")
	}

	if c.Outputs == nil {
		c.Logger.Log(logger.Info, pkg+"no output defined, defaulting", "output", defaultOutput)
		c.Outputs = append(c.Outputs, defaultOutput)
	} else {
		for i, o := range c.Outputs {
			switch o {
			case File:
			case RTMP:
				if c.RtmpUrl == "" {
					c.Logger.Log(logger.Info, pkg+"no RTMP URL: falling back to HTTP")
					c.Outputs[i] = HTTP
					// FIXME(kortschak): Does this want the same line as below?
					//  c.FramesPerClip = httpFramesPerClip
					break
				}
				c.Logger.Log(logger.Info, pkg+"defaulting frames per clip for rtmp out", "framesPerClip", defaultFramesPerClip)
				c.FramesPerClip = defaultFramesPerClip
				c.SendRetry = true
			case HTTP, RTP:
				c.Logger.Log(logger.Info, pkg+"defaulting frames per clip for http out", "framesPerClip", httpFramesPerClip)
				c.FramesPerClip = httpFramesPerClip
			default:
				return errors.New("bad output type defined in config")
			}
		}
	}

	if c.BurstPeriod == 0 {
		c.Logger.Log(logger.Info, pkg+"no burst period defined, defaulting", "burstPeriod", defaultBurstPeriod)
		c.BurstPeriod = defaultBurstPeriod
	}

	if c.FramesPerClip < 1 {
		c.Logger.Log(logger.Info, pkg+"no FramesPerClip defined, defaulting", "framesPerClip", defaultFramesPerClip)
		c.FramesPerClip = defaultFramesPerClip
	}

	if c.Rotation > 359 {
		c.Logger.Log(logger.Warning, pkg+"bad rotate angle, defaulting", "angle", defaultRotation)
		c.Rotation = defaultRotation
	}

	if c.Width == 0 {
		c.Logger.Log(logger.Info, pkg+"no width defined, defaulting", "width", defaultWidth)
		c.Width = defaultWidth
	}

	if c.Height == 0 {
		c.Logger.Log(logger.Info, pkg+"no height defined, defaulting", "height", defaultHeight)
		c.Height = defaultHeight
	}

	if c.FrameRate == 0 {
		c.Logger.Log(logger.Info, pkg+"no frame rate defined, defaulting", "fps", defaultFrameRate)
		c.FrameRate = defaultFrameRate
	}

	if c.Bitrate == 0 {
		c.Logger.Log(logger.Info, pkg+"no bitrate defined, defaulting", "bitrate", defaultBitrate)
		c.Bitrate = defaultBitrate
	}

	if c.IntraRefreshPeriod == 0 {
		c.Logger.Log(logger.Info, pkg+"no intra refresh defined, defaulting", "intraRefresh", defaultIntraRefreshPeriod)
		c.IntraRefreshPeriod = defaultIntraRefreshPeriod
	}

	if c.Quantization == 0 {
		c.Logger.Log(logger.Info, pkg+"no quantization defined, defaulting", "quantization", defaultQuantization)
		c.Quantization = defaultQuantization
	} else if c.Quantization > 51 {
		return errors.New("quantisation is over threshold")
	}

	if c.RtpAddress == "" {
		c.RtpAddress = defaultRtpAddr
	}

	switch {
	case c.Brightness == 0:
		c.Logger.Log(logger.Info, pkg+"brightness undefined, defaulting", "brightness", defaultBrightness)
		c.Brightness = defaultBrightness
	case c.Brightness < 0 || c.Brightness > 100:
		return errors.New(pkg + "bad brightness defined in config")
	}

	if c.Saturation < -100 || c.Saturation > 100 {
		return errors.New(pkg + "bad saturation setting in config")
	}

	switch {
	case c.Exposure == "":
		c.Logger.Log(logger.Info, pkg+"exposure undefined, defaulting", "exposure", defaultExposure)
		c.Exposure = defaultExposure
	case !stringInSlice(c.Exposure, ExposureModes[:]):
		return errors.New(pkg + "bad exposure setting in config")
	}

	switch {
	case c.AutoWhiteBalance == "":
		c.Logger.Log(logger.Info, pkg+"auto white balance undefined, defaulting", "autoWhiteBalance", defaultAutoWhiteBalance)
		c.AutoWhiteBalance = defaultAutoWhiteBalance
	case !stringInSlice(c.AutoWhiteBalance, AutoWhiteBalanceModes[:]):
		return errors.New(pkg + "bad auto white balance setting in config")
	}

	return nil
}

// stringInSlice returns true if want is in slice.
func stringInSlice(want string, slice []string) bool {
	for _, s := range slice {
		if s == want {
			return true
		}
	}
	return false
}