//
//  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"}
	rhl      = log.New(os.Stderr, "[rhimport]\t", log.LstdFlags)
	rhdl     = log.New(ioutil.Discard, "[rhimport-dbg]\t", log.LstdFlags)
)

func init() {
	if _, exists := os.LookupEnv("RHIMPORT_DEBUG"); exists {
		rhdl.SetOutput(os.Stderr)
	}

	curl.GlobalInit(curl.GLOBAL_ALL)
	fetcherInit()
}

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 Context struct {
	conf                 *Config
	db                   *rddb.DBChan
	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 []byte
	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) *Context {
	ctx := new(Context)
	ctx.conf = conf
	ctx.db = db
	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 = nil
	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
}