//
//  rhimportd
//
//  The Radio Helsinki Rivendell Import Daemon
//
//
//  Copyright (C) 2015-2016 Christian Pointner <equinox@helsinki.at>
//
//  This file is part of rhimportd.
//
//  rhimportd is free software: you can redistribute it and/or modify
//  it under the terms of the GNU General Public License as published by
//  the Free Software Foundation, either version 3 of the License, or
//  any later version.
//
//  rhimportd 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 rhimportd. If not, see <http://www.gnu.org/licenses/>.
//

package rhimport

import (
	"bufio"
	"fmt"
	"io/ioutil"
	"log"
	"os"
	"path"
	"strings"

	"code.helsinki.at/rhrd-go/rddb"
	"github.com/andelf/go-curl"
)

const (
	CART_MAX = 999999
	CUT_MAX  = 999
	// not sure if rdxport.cgi can handle filesizes > MAX(INT32)
	FILESIZE_MAX = (2 * 1024 * 1024 * 1024) - 1

	// TODO: make this configurable
	ARCHIV_HOST      = "archiv.helsinki.at"
	ARCHIV_USER      = "rhimport"
	ARCHIV_BASE_PATH = "/srv/archiv"

	CBA_API_KEY_FILE = "/etc/cba-api.key"
)

var (
	bool2str = map[bool]string{false: "0", true: "1"}
)

func Init(stdlog, dbglog *log.Logger) {
	curl.GlobalInit(curl.GLOBAL_ALL)
	fetcherInit(stdlog, dbglog)
}

type ProgressCB func(step int, stepName string, current, total float64, title string, cart, cut uint, userdata interface{}) bool
type DoneCB func(result Result, userdata interface{}) bool

type Result struct {
	ResponseCode int
	ErrorString  string
	Cart         uint
	Cut          uint
	SourceFile   string
}

type FilePolicy int

const (
	Auto FilePolicy = iota
	Keep
	Delete
	DeleteWithDir
)

func (p *FilePolicy) String() string {
	switch *p {
	case Auto:
		return "auto"
	case Keep:
		return "keep"
	case Delete:
		return "delete"
	case DeleteWithDir:
		return "delete-with-dir"
	}
	return "unknown"
}

func (p *FilePolicy) FromString(str string) error {
	switch str {
	case "auto":
		*p = Auto
	case "keep":
		*p = Keep
	case "delete":
		*p = Delete
	case "delete-with-dir":
		*p = DeleteWithDir
	default:
		return fmt.Errorf("must be on of: auto, keep, delete or delete-with-dir")
	}
	return nil
}

func getCBAApiKey() string {
	key_file, err := os.Open(CBA_API_KEY_FILE)
	if err == nil {
		defer key_file.Close()
		data, _ := bufio.NewReader(key_file).ReadString('\n')
		return strings.TrimSpace(string(data))
	}
	return ""
}

type AttachmentChunk struct {
	Data  []byte
	Error error
}

type Context struct {
	conf                 *Config
	db                   *rddb.DBChan
	stdlog               *log.Logger
	dbglog               *log.Logger
	UserName             string
	Password             string
	Trusted              bool
	ShowId               uint
	ClearShowCarts       bool
	ShowCarts            []uint
	GroupName            string
	Cart                 uint
	ClearCart            bool
	Cut                  uint
	Channels             uint
	NormalizationLevel   int
	AutotrimLevel        int
	UseMetaData          bool
	SourceUri            string
	AttachmentChan       chan AttachmentChunk
	FetchConverter       string
	OrigFilename         string
	Title                string
	SourceFile           string
	DeleteSourceFile     bool
	DeleteSourceDir      bool
	SourceFilePolicy     FilePolicy
	LoudnessCorr         float64
	ProgressCallBack     ProgressCB
	ProgressCallBackData interface{}
	Cancel               <-chan bool
}

func NewContext(conf *Config, db *rddb.DBChan, stdlog, dbglog *log.Logger) *Context {
	if stdlog == nil {
		stdlog = log.New(ioutil.Discard, "", 0)
	}
	if dbglog == nil {
		dbglog = log.New(ioutil.Discard, "", 0)
	}

	ctx := new(Context)
	ctx.conf = conf
	ctx.db = db
	ctx.stdlog = stdlog
	ctx.dbglog = dbglog
	ctx.UserName = ""
	ctx.Password = ""
	ctx.Trusted = false
	ctx.ShowId = 0
	ctx.ClearShowCarts = false
	ctx.GroupName = ""
	ctx.Cart = 0
	ctx.ClearCart = false
	ctx.Cut = 0
	ctx.Channels = conf.ImportParamDefaults.Channels
	ctx.NormalizationLevel = conf.ImportParamDefaults.NormalizationLevel
	ctx.AutotrimLevel = conf.ImportParamDefaults.AutotrimLevel
	ctx.UseMetaData = conf.ImportParamDefaults.UseMetaData
	ctx.AttachmentChan = make(chan AttachmentChunk, 32)
	ctx.FetchConverter = "ffmpeg-bs1770"
	ctx.OrigFilename = ""
	ctx.Title = ""
	ctx.SourceFile = ""
	ctx.DeleteSourceFile = false
	ctx.DeleteSourceDir = false
	ctx.LoudnessCorr = 0.0
	ctx.SourceFilePolicy = Auto
	ctx.ProgressCallBack = nil
	ctx.Cancel = nil

	return ctx
}

func (ctx *Context) SanityCheck() error {
	if ctx.UserName == "" {
		return fmt.Errorf("empty Username is not allowed")
	}
	if ctx.Password == "" && !ctx.Trusted {
		return fmt.Errorf("empty Password on untrusted control interface is not allowed")
	}
	if ctx.ShowId != 0 {
		if ctx.ShowId != 0 && ctx.ShowId > CART_MAX {
			return fmt.Errorf("ShowId %d is outside of allowed range (0 < show-id < %d)", ctx.ShowId, CART_MAX)
		}
		if err := ctx.getShowInfo(); err != nil {
			return err
		}
		if ctx.Cart == 0 {
			return nil
		}
		if ctx.Cart > CART_MAX {
			return fmt.Errorf("Cart %d is outside of allowed range (0 < cart < %d)", ctx.Cart, CART_MAX)
		}
		for _, cart := range ctx.ShowCarts {
			if cart == ctx.Cart {
				return nil
			}
		}
		return fmt.Errorf("Cart %d is not part of the show with show-id %d", ctx.Cart, ctx.ShowId)
	}
	if ctx.GroupName != "" {
		ismusic, err := ctx.checkMusicGroup()
		if err != nil {
			return err
		}
		if !ismusic {
			return fmt.Errorf("supplied GroupName '%s' is not a music pool", ctx.GroupName)
		}
		if ctx.Cart != 0 || ctx.Cut != 0 {
			return fmt.Errorf("Cart and Cut must not be supplied when importing into a music group")
		}
		return ctx.getMusicInfo()
	}
	if ctx.Cart == 0 {
		return fmt.Errorf("either ShowId, PoolName or CartNumber must be supplied")
	}
	if ctx.Cart > CART_MAX {
		return fmt.Errorf("Cart %d is outside of allowed range (0 < cart < %d)", ctx.Cart, CART_MAX)
	}
	if ctx.Cut != 0 && ctx.Cut > CUT_MAX {
		return fmt.Errorf("Cut %d is outside of allowed range (0 < cart < %d)", ctx.Cut, CUT_MAX)
	}
	if ctx.Channels != 1 && ctx.Channels != 2 {
		return fmt.Errorf("channles must be 1 or 2")
	}
	return nil
}

func (ctx *Context) getPassword(cached bool) (err error) {
	ctx.Password, err = ctx.db.GetPassword(ctx.UserName, cached)
	return
}

func (ctx *Context) CheckPassword() (bool, error) {
	return ctx.db.CheckPassword(ctx.UserName, ctx.Password)
}

func (ctx *Context) getGroupOfCart() (err error) {
	ctx.GroupName, err = ctx.db.GetGroupOfCart(ctx.Cart)
	return
}

func (ctx *Context) getShowInfo() (err error) {
	ctx.GroupName, ctx.NormalizationLevel, ctx.AutotrimLevel, ctx.ShowCarts, err = ctx.db.GetShowInfo(ctx.ShowId)
	ctx.Channels = 2
	ctx.UseMetaData = true
	return
}

func (ctx *Context) checkMusicGroup() (bool, error) {
	return ctx.db.CheckMusicGroup(ctx.GroupName)
}

func (ctx *Context) getMusicInfo() (err error) {
	ctx.NormalizationLevel, ctx.AutotrimLevel, err = ctx.db.GetMusicInfo(ctx.GroupName)
	ctx.Channels = 2
	ctx.UseMetaData = true
	ctx.Cart = 0
	ctx.Cut = 0
	return
}

func (ctx *Context) updateCutCartTitle() (err error) {
	filename := ctx.OrigFilename
	if filename == "" {
		filename = ctx.SourceFile
	}
	return ctx.db.UpdateCutCartTitle(ctx.Cart, ctx.Cut, ctx.GroupName, filename)
}

func (ctx *Context) reportProgress(step int, stepName string, current, total float64) {
	if ctx.ProgressCallBack != nil {
		title := ctx.Title
		if title == "" {
			title = path.Base(ctx.OrigFilename)
			if title == "" {
				title = path.Base(ctx.SourceFile)
			}
		}
		if keep := ctx.ProgressCallBack(step, stepName, current, total, title, ctx.Cart, ctx.Cut, ctx.ProgressCallBackData); !keep {
			ctx.ProgressCallBack = nil
		}
	}
}

func (ctx *Context) isCanceled() bool {
	return ctx.Cancel != nil && len(ctx.Cancel) > 0
}