//
//  rhimportd
//
//  The Radio Helsinki Rivendell Import Daemon
//
//
//  Copyright (C) 2015 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"
	"bytes"
	"fmt"
	"github.com/golang-basic/go-curl"
	"mime/multipart"
	"net/http"
	"os"
	"path"
)

const (
	CART_MAX = 999999
	CUT_MAX  = 999
)

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

type ImportProgressCB func(step int, step_name string, progress float64, userdata interface{})

type ImportContext struct {
	conf                 *Config
	rddb                 *RdDbChan
	UserName             string
	Password             string
	Trusted              bool
	ShowId               uint
	ClearShowCarts       bool
	GroupName            string
	Cart                 uint
	ClearCart            bool
	Cut                  uint
	Channels             uint
	NormalizationLevel   int
	AutotrimLevel        int
	UseMetaData          bool
	SourceUri            string
	SourceFile           string
	DeleteSourceFile     bool
	DeleteSourceDir      bool
	ProgressCallBack     ImportProgressCB
	ProgressCallBackData interface{}
	Cancel               <-chan bool
}

func NewImportContext(conf *Config, rddb *RdDbChan, user string) *ImportContext {
	ctx := new(ImportContext)
	ctx.conf = conf
	ctx.rddb = rddb
	ctx.UserName = user
	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.SourceFile = ""
	ctx.DeleteSourceFile = false
	ctx.DeleteSourceDir = false
	ctx.ProgressCallBack = nil
	ctx.Cancel = nil

	return ctx
}

func (ctx *ImportContext) 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 ctx.Cart != 0 && ctx.Cart > CART_MAX {
			return fmt.Errorf("Cart %d is outside of allowed range (0 < cart < %d)", ctx.Cart, CART_MAX)
		}
		return nil
	}
	if ctx.GroupName != "" {
		ismusic, err := ctx.checkMusicGroup()
		if err != nil {
			return err
		}
		if !ismusic {
			return fmt.Errorf("supplied GroupName is not a music pool")
		}
		if ctx.Cart != 0 || ctx.Cut != 0 {
			return fmt.Errorf("Cart and Cut must not be supplied when importing into a music group")
		}
		return nil
	}
	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 *ImportContext) getPassword(cached bool) (err error) {
	res_ch := make(chan getPasswordResult)
	req := getPasswordRequest{}
	req.username = ctx.UserName
	req.cached = cached
	req.response = res_ch
	ctx.rddb.getPasswordChan <- req

	res := <-res_ch
	if res.err != nil {
		return res.err
	}
	ctx.Password = res.password
	return nil
}

func (ctx *ImportContext) getGroupOfCart() error {
	res_ch := make(chan getGroupOfCartResult)
	req := getGroupOfCartRequest{}
	req.cart = ctx.Cart
	req.response = res_ch
	ctx.rddb.getGroupOfCartChan <- req

	res := <-res_ch
	if res.err != nil {
		return res.err
	}
	ctx.GroupName = res.group
	return nil
}

func (ctx *ImportContext) getShowInfo() (carts []uint, err error) {
	res_ch := make(chan getShowInfoResult)
	req := getShowInfoRequest{}
	req.showid = ctx.ShowId
	req.response = res_ch
	ctx.rddb.getShowInfoChan <- req

	res := <-res_ch
	if res.err != nil {
		err = res.err
		return
	}
	ctx.GroupName = res.group
	ctx.NormalizationLevel = res.norm_lvl
	ctx.AutotrimLevel = res.trim_lvl
	ctx.Channels = 2
	ctx.UseMetaData = true
	carts = res.carts
	return
}

func (ctx *ImportContext) checkMusicGroup() (bool, error) {
	res_ch := make(chan checkMusicGroupResult)
	req := checkMusicGroupRequest{}
	req.group = ctx.GroupName
	req.response = res_ch
	ctx.rddb.checkMusicGroupChan <- req

	res := <-res_ch
	if res.err != nil {
		return false, res.err
	}
	return res.ismusic, nil
}

func (ctx *ImportContext) getMusicInfo() (err error) {
	res_ch := make(chan getMusicInfoResult)
	req := getMusicInfoRequest{}
	req.group = ctx.GroupName
	req.response = res_ch
	ctx.rddb.getMusicInfoChan <- req

	res := <-res_ch
	if res.err != nil {
		return res.err
	}
	ctx.NormalizationLevel = res.norm_lvl
	ctx.AutotrimLevel = res.trim_lvl
	ctx.Channels = 2
	ctx.UseMetaData = true
	ctx.Cart = 0
	ctx.Cut = 0
	return
}

type ImportResult struct {
	ResponseCode int
	ErrorString  string
	Cart         uint
	Cut          uint
}

func (self *ImportResult) fromRDWebResult(rdres *RDWebResult) {
	self.ResponseCode = rdres.ResponseCode
	self.ErrorString = rdres.ErrorString
	if rdres.AudioConvertError != 0 {
		self.ErrorString += fmt.Sprintf(", Audio Convert Error: %d", rdres.AudioConvertError)
	}
}

func add_cart(ctx *ImportContext, res *ImportResult) (err error) {
	rhdl.Printf("importer: add_cart() called for cart: %d", ctx.Cart)

	if ctx.GroupName == "" {
		if err = ctx.getGroupOfCart(); err != nil {
			return
		}
	}

	var b bytes.Buffer
	w := multipart.NewWriter(&b)

	if err = w.WriteField("COMMAND", "12"); err != nil {
		return
	}
	if err = w.WriteField("LOGIN_NAME", ctx.UserName); err != nil {
		return
	}
	if err = w.WriteField("PASSWORD", ctx.Password); err != nil {
		return
	}
	if err = w.WriteField("GROUP_NAME", ctx.GroupName); err != nil {
		return
	}
	if err = w.WriteField("TYPE", "audio"); err != nil {
		return
	}
	if ctx.Cart != 0 {
		if err = w.WriteField("CART_NUMBER", fmt.Sprintf("%d", ctx.Cart)); err != nil {
			return
		}
	}
	w.Close()

	var resp *http.Response
	if resp, err = send_post_request(ctx.conf.RDXportEndpoint, &b, w.FormDataContentType()); err != nil {
		return
	}
	defer resp.Body.Close()

	if resp.StatusCode != http.StatusOK {
		var rdres *RDWebResult
		if rdres, err = NewRDWebResultFromXML(resp.Body); err != nil {
			return
		}
		res.fromRDWebResult(rdres)
		res.Cart = ctx.Cart
		return
	}
	var cartadd *RDCartAdd
	if cartadd, err = NewRDCartAddFromXML(resp.Body); err != nil {
		return
	}
	res.ResponseCode = resp.StatusCode
	res.ErrorString = "OK"
	res.Cart = cartadd.Carts[0].Number
	ctx.Cart = res.Cart
	return
}

func add_cut(ctx *ImportContext, res *ImportResult) (err error) {
	rhdl.Printf("importer: add_cut() called for cart/cut: %d/%d", ctx.Cart, ctx.Cut)
	var b bytes.Buffer
	w := multipart.NewWriter(&b)

	if err = w.WriteField("COMMAND", "10"); err != nil {
		return
	}
	if err = w.WriteField("LOGIN_NAME", ctx.UserName); err != nil {
		return
	}
	if err = w.WriteField("PASSWORD", ctx.Password); err != nil {
		return
	}
	if err = w.WriteField("CART_NUMBER", fmt.Sprintf("%d", ctx.Cart)); err != nil {
		return
	}
	w.Close()

	var resp *http.Response
	if resp, err = send_post_request(ctx.conf.RDXportEndpoint, &b, w.FormDataContentType()); err != nil {
		return
	}
	defer resp.Body.Close()

	if resp.StatusCode != http.StatusOK {
		var rdres *RDWebResult
		if rdres, err = NewRDWebResultFromXML(resp.Body); err != nil {
			return
		}
		res.fromRDWebResult(rdres)
		res.Cart = ctx.Cart
		res.Cut = ctx.Cut
		return
	}
	var cutadd *RDCutAdd
	if cutadd, err = NewRDCutAddFromXML(resp.Body); err != nil {
		return
	}
	res.ResponseCode = resp.StatusCode
	res.ErrorString = "OK"
	res.Cart = ctx.Cart
	res.Cut = cutadd.Cuts[0].Number
	ctx.Cut = cutadd.Cuts[0].Number
	return
}

func remove_cart(ctx *ImportContext, res *ImportResult) (err error) {
	rhdl.Printf("importer: remove_cart() called for cart: %d", ctx.Cart)
	var b bytes.Buffer
	w := multipart.NewWriter(&b)

	if err = w.WriteField("COMMAND", "13"); err != nil {
		return
	}
	if err = w.WriteField("LOGIN_NAME", ctx.UserName); err != nil {
		return
	}
	if err = w.WriteField("PASSWORD", ctx.Password); err != nil {
		return
	}
	if err = w.WriteField("CART_NUMBER", fmt.Sprintf("%d", ctx.Cart)); err != nil {
		return
	}
	w.Close()

	var resp *http.Response
	if resp, err = send_post_request(ctx.conf.RDXportEndpoint, &b, w.FormDataContentType()); err != nil {
		return
	}
	defer resp.Body.Close()

	var rdres *RDWebResult
	if rdres, err = NewRDWebResultFromXML(resp.Body); err != nil {
		return
	}
	res.fromRDWebResult(rdres)
	res.Cart = ctx.Cart
	return
}

func remove_cut(ctx *ImportContext, res *ImportResult) (err error) {
	rhdl.Printf("importer: remove_cut() called for cart/cut: %d/%d", ctx.Cart, ctx.Cut)
	var b bytes.Buffer
	w := multipart.NewWriter(&b)

	if err = w.WriteField("COMMAND", "11"); err != nil {
		return
	}
	if err = w.WriteField("LOGIN_NAME", ctx.UserName); err != nil {
		return
	}
	if err = w.WriteField("PASSWORD", ctx.Password); err != nil {
		return
	}
	if err = w.WriteField("CART_NUMBER", fmt.Sprintf("%d", ctx.Cart)); err != nil {
		return
	}
	if err = w.WriteField("CUT_NUMBER", fmt.Sprintf("%d", ctx.Cut)); err != nil {
		return
	}
	w.Close()

	var resp *http.Response
	if resp, err = send_post_request(ctx.conf.RDXportEndpoint, &b, w.FormDataContentType()); err != nil {
		return
	}
	defer resp.Body.Close()

	var rdres *RDWebResult
	if rdres, err = NewRDWebResultFromXML(resp.Body); err != nil {
		return
	}
	res.fromRDWebResult(rdres)
	res.Cart = ctx.Cart
	res.Cut = ctx.Cut
	return
}

func send_post_request(url string, b *bytes.Buffer, contenttype string) (resp *http.Response, err error) {
	var req *http.Request
	if req, err = http.NewRequest("POST", url, b); err != nil {
		return
	}
	if contenttype != "" {
		req.Header.Set("Content-Type", contenttype)
	}

	client := &http.Client{}
	if resp, err = client.Do(req); err != nil {
		return
	}
	return
}

func import_audio_create_request(ctx *ImportContext, easy *curl.CURL) (form *curl.Form, err error) {
	form = curl.NewForm()

	if err = form.Add("COMMAND", "2"); err != nil {
		return
	}
	if err = form.Add("LOGIN_NAME", ctx.UserName); err != nil {
		return
	}
	if err = form.Add("PASSWORD", ctx.Password); err != nil {
		return
	}
	if err = form.Add("CART_NUMBER", fmt.Sprintf("%d", ctx.Cart)); err != nil {
		return
	}
	if err = form.Add("CUT_NUMBER", fmt.Sprintf("%d", ctx.Cut)); err != nil {
		return
	}
	if err = form.Add("CHANNELS", fmt.Sprintf("%d", ctx.Channels)); err != nil {
		return
	}
	if err = form.Add("NORMALIZATION_LEVEL", fmt.Sprintf("%d", ctx.NormalizationLevel)); err != nil {
		return
	}
	if err = form.Add("AUTOTRIM_LEVEL", fmt.Sprintf("%d", ctx.AutotrimLevel)); err != nil {
		return
	}
	if err = form.Add("USE_METADATA", bool2str[ctx.UseMetaData]); err != nil {
		return
	}
	if err = form.AddFile("FILENAME", ctx.SourceFile); err != nil {
		return
	}

	return
}

func import_audio(ctx *ImportContext, res *ImportResult) (err error) {
	rhdl.Printf("importer: import_audio() called for cart/cut: %d/%d", ctx.Cart, ctx.Cut)
	easy := curl.EasyInit()

	if easy != nil {
		defer easy.Cleanup()

		easy.Setopt(curl.OPT_URL, ctx.conf.RDXportEndpoint)
		easy.Setopt(curl.OPT_POST, true)

		var form *curl.Form
		if form, err = import_audio_create_request(ctx, easy); err != nil {
			return
		}
		easy.Setopt(curl.OPT_HTTPPOST, form)
		easy.Setopt(curl.OPT_HTTPHEADER, []string{"Expect:"})

		var resbody bytes.Buffer
		easy.Setopt(curl.OPT_WRITEFUNCTION, func(ptr []byte, userdata interface{}) bool {
			b := userdata.(*bytes.Buffer)
			b.Write(ptr)
			return true
		})
		easy.Setopt(curl.OPT_WRITEDATA, &resbody)

		easy.Setopt(curl.OPT_NOPROGRESS, false)
		easy.Setopt(curl.OPT_PROGRESSFUNCTION, func(dltotal, dlnow, ultotal, ulnow float64, userdata interface{}) bool {
			if ctx.Cancel != nil && len(ctx.Cancel) > 0 {
				res.ResponseCode = http.StatusNoContent
				res.ErrorString = "canceled"
				return false
			}

			if ctx.ProgressCallBack != nil {
				ctx.ProgressCallBack(2, "importing", ulnow/ultotal, ctx.ProgressCallBackData)
			}
			return true
		})
		easy.Setopt(curl.OPT_PROGRESSDATA, ctx)

		if err = easy.Perform(); err != nil {
			if res.ResponseCode == http.StatusNoContent {
				rhl.Printf("import to cart/cat %d/%d got canceled", ctx.Cart, ctx.Cut)
				res.Cart = ctx.Cart
				res.Cut = ctx.Cut
				err = nil
			} else {
				err = fmt.Errorf("importer: %s", err)
			}
			return
		}

		var rdres *RDWebResult
		if rdres, err = NewRDWebResultFromXML(bufio.NewReader(&resbody)); err != nil {
			return
		}
		res.fromRDWebResult(rdres)
		res.Cart = ctx.Cart
		res.Cut = ctx.Cut
	} else {
		err = fmt.Errorf("Error initializing libcurl")
	}

	return
}

func add_cart_cut(ctx *ImportContext, res *ImportResult) (err error) {
	if err = add_cart(ctx, res); err != nil || res.ResponseCode != http.StatusOK {
		return
	}
	if err = add_cut(ctx, res); err != nil || res.ResponseCode != http.StatusOK {
		return remove_cart(ctx, &ImportResult{ResponseCode: http.StatusOK})
	}
	return
}

func remove_add_cart_cut(ctx *ImportContext, res *ImportResult) (err error) {
	if err = remove_cart(ctx, res); err != nil || (res.ResponseCode != http.StatusOK && res.ResponseCode != http.StatusNotFound) {
		return
	}
	return add_cart_cut(ctx, res)
}

func is_cart_member_of_show(ctx *ImportContext, res *ImportResult, carts []uint) (found bool) {
	if ctx.Cart == 0 {
		return true
	}
	for _, cart := range carts {
		if cart == ctx.Cart {
			return true
		}
	}
	res.ResponseCode = http.StatusBadRequest
	res.ErrorString = fmt.Sprintf("Requested cart %d is not a member of show: %d", ctx.Cart, ctx.ShowId)
	res.Cart = ctx.Cart
	return false
}

func clear_show_carts(ctx *ImportContext, res *ImportResult, carts []uint) (err error) {
	if ctx.ClearShowCarts {
		orig_cart := ctx.Cart
		for _, cart := range carts {
			ctx.Cart = cart
			if err = remove_cart(ctx, res); err != nil || (res.ResponseCode != http.StatusOK && res.ResponseCode != http.StatusNotFound) {
				return
			}
		}
		ctx.Cart = orig_cart
	}
	return
}

func add_show_cart_cut(ctx *ImportContext, res *ImportResult, carts []uint) (err error) {
	if err = add_cart(ctx, res); err != nil || res.ResponseCode != http.StatusOK {
		return
	}
	for _, cart := range carts {
		if cart == ctx.Cart {
			if err = add_cut(ctx, res); err != nil || res.ResponseCode != http.StatusOK {
				return remove_cart(ctx, &ImportResult{ResponseCode: http.StatusOK})
			}
			return
		}
	}
	if err = remove_cart(ctx, res); err != nil || res.ResponseCode != http.StatusOK {
		return
	}
	res.ResponseCode = http.StatusForbidden
	res.ErrorString = fmt.Sprintf("Show %d has no free carts left", ctx.ShowId)
	return
}

func cleanup_files(ctx *ImportContext) {
	if ctx.DeleteSourceFile {
		rhdl.Printf("importer: removing file: %s", ctx.SourceFile)
		if err := os.Remove(ctx.SourceFile); err != nil {
			rhl.Printf("importer: error removing source file: %s", err)
			return
		}
		if ctx.DeleteSourceDir {
			dir := path.Dir(ctx.SourceFile)
			rhdl.Printf("importer: also removing directory: %s", dir)
			if err := os.Remove(dir); err != nil {
				rhl.Printf("importer: error removing source directory: %s", err)
			}
		}
	}
	return
}

func ImportFile(ctx *ImportContext) (res *ImportResult, err error) {
	defer cleanup_files(ctx)

	rhl.Printf("importer: ImportFile called with: show-id: %d, pool-name: '%s', cart/cut: %d/%d", ctx.ShowId, ctx.GroupName, ctx.Cart, ctx.Cut)

	if ctx.ProgressCallBack != nil {
		ctx.ProgressCallBack(2, "importing", 0.0, ctx.ProgressCallBackData)
	}

	if ctx.Trusted {
		if err = ctx.getPassword(true); err != nil {
			return
		}
	}

	rmCartOnErr := false
	rmCutOnErr := false
	res = &ImportResult{ResponseCode: http.StatusOK}
	if ctx.ShowId != 0 {
		var show_carts []uint
		if show_carts, err = ctx.getShowInfo(); err != nil {
			return
		}
		if !is_cart_member_of_show(ctx, res, show_carts) {
			return
		}
		if err = clear_show_carts(ctx, res, show_carts); err != nil || (res.ResponseCode != http.StatusOK && res.ResponseCode != http.StatusNotFound) {
			return
		}
		if ctx.ClearCart && !ctx.ClearShowCarts {
			if err = remove_add_cart_cut(ctx, res); err != nil || res.ResponseCode != http.StatusOK {
				return
			}
		} else {
			if err = add_show_cart_cut(ctx, res, show_carts); err != nil || res.ResponseCode != http.StatusOK {
				return
			}
		}
		rmCartOnErr = true
	} else if ctx.GroupName != "" {
		if err = ctx.getMusicInfo(); err != nil {
			return
		}
		if err = add_cart_cut(ctx, res); err != nil || res.ResponseCode != http.StatusOK {
			return
		}
		rmCartOnErr = true
	} else if ctx.Cart != 0 && ctx.Cut == 0 {
		if ctx.ClearCart {
			if err = remove_add_cart_cut(ctx, res); err != nil || res.ResponseCode != http.StatusOK {
				return
			}
			rmCartOnErr = true
		} else {
			if err = add_cut(ctx, res); err != nil {
				return
			}
			if res.ResponseCode != http.StatusOK {
				if err = add_cart_cut(ctx, res); err != nil || res.ResponseCode != http.StatusOK {
					return
				}
				rmCartOnErr = true
			} else {
				rmCutOnErr = true
			}
		}
	}

	if ctx.Cart != 0 && ctx.Cut != 0 {
		if err = import_audio(ctx, res); err != nil {
			return
		}
		if res.ResponseCode != http.StatusOK {
			rhl.Printf("Fileimport has failed (Cart/Cut %d/%d): %s", res.Cart, res.Cut, res.ErrorString)
			rmres := ImportResult{ResponseCode: http.StatusOK}
			if rmCartOnErr {
				if err = remove_cart(ctx, &rmres); err != nil {
					return
				}
			} else if rmCutOnErr {
				if err = remove_cut(ctx, &rmres); err != nil {
					return
				}
			}
		} else {
			rhl.Printf("File got succesfully imported into Cart/Cut %d/%d", res.Cart, res.Cut)
		}
	} else {
		res.ResponseCode = http.StatusBadRequest
		res.ErrorString = "importer: The request doesn't contain enough information to be processed"
	}

	return
}