// Copyright 2016 The go-ethereum Authors
// This file is part of go-ethereum.
//
// go-ethereum 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
// (at your option) any later version.
//
// go-ethereum 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 go-ethereum. If not, see <http://www.gnu.org/licenses/>.

// Command bzzup uploads files to the swarm HTTP API.
package main

import (
	"bytes"
	"encoding/json"
	"fmt"
	"io"
	"io/ioutil"
	"mime"
	"net/http"
	"os"
	"os/user"
	"path"
	"path/filepath"
	"strings"

	"github.com/ethereum/go-ethereum/cmd/utils"
	"github.com/ethereum/go-ethereum/log"
	"gopkg.in/urfave/cli.v1"
)

func upload(ctx *cli.Context) {
	args := ctx.Args()
	var (
		bzzapi       = strings.TrimRight(ctx.GlobalString(SwarmApiFlag.Name), "/")
		recursive    = ctx.GlobalBool(SwarmRecursiveUploadFlag.Name)
		wantManifest = ctx.GlobalBoolT(SwarmWantManifestFlag.Name)
		defaultPath  = ctx.GlobalString(SwarmUploadDefaultPath.Name)
	)
	if len(args) != 1 {
		utils.Fatalf("Need filename as the first and only argument")
	}

	var (
		file   = args[0]
		client = &client{api: bzzapi}
	)
	fi, err := os.Stat(expandPath(file))
	if err != nil {
		utils.Fatalf("Failed to stat file: %v", err)
	}
	if fi.IsDir() {
		if !recursive {
			utils.Fatalf("Argument is a directory and recursive upload is disabled")
		}
		if !wantManifest {
			utils.Fatalf("Manifest is required for directory uploads")
		}
		mhash, err := client.uploadDirectory(file, defaultPath)
		if err != nil {
			utils.Fatalf("Failed to upload directory: %v", err)
		}
		fmt.Println(mhash)
		return
	}
	entry, err := client.uploadFile(file, fi)
	if err != nil {
		utils.Fatalf("Upload failed: %v", err)
	}
	mroot := manifest{[]manifestEntry{entry}}
	if !wantManifest {
		// Print the manifest. This is the only output to stdout.
		mrootJSON, _ := json.MarshalIndent(mroot, "", "  ")
		fmt.Println(string(mrootJSON))
		return
	}
	hash, err := client.uploadManifest(mroot)
	if err != nil {
		utils.Fatalf("Manifest upload failed: %v", err)
	}
	fmt.Println(hash)
}

// Expands a file path
// 1. replace tilde with users home dir
// 2. expands embedded environment variables
// 3. cleans the path, e.g. /a/b/../c -> /a/c
// Note, it has limitations, e.g. ~someuser/tmp will not be expanded
func expandPath(p string) string {
	if strings.HasPrefix(p, "~/") || strings.HasPrefix(p, "~\\") {
		if home := homeDir(); home != "" {
			p = home + p[1:]
		}
	}
	return path.Clean(os.ExpandEnv(p))
}

func homeDir() string {
	if home := os.Getenv("HOME"); home != "" {
		return home
	}
	if usr, err := user.Current(); err == nil {
		return usr.HomeDir
	}
	return ""
}

// client wraps interaction with the swarm HTTP gateway.
type client struct {
	api string
}

// manifest is the JSON representation of a swarm manifest.
type manifestEntry struct {
	Hash        string `json:"hash,omitempty"`
	ContentType string `json:"contentType,omitempty"`
	Path        string `json:"path,omitempty"`
}

// manifest is the JSON representation of a swarm manifest.
type manifest struct {
	Entries []manifestEntry `json:"entries,omitempty"`
}

func (c *client) uploadDirectory(dir string, defaultPath string) (string, error) {
	mhash, err := c.postRaw("application/json", 2, ioutil.NopCloser(bytes.NewReader([]byte("{}"))))
	if err != nil {
		return "", fmt.Errorf("failed to upload empty manifest")
	}
	if len(defaultPath) > 0 {
		fi, err := os.Stat(defaultPath)
		if err != nil {
			return "", err
		}
		mhash, err = c.uploadToManifest(mhash, "", defaultPath, fi)
		if err != nil {
			return "", err
		}
	}
	prefix := filepath.ToSlash(filepath.Clean(dir)) + "/"
	err = filepath.Walk(dir, func(path string, fi os.FileInfo, err error) error {
		if err != nil || fi.IsDir() {
			return err
		}
		if !strings.HasPrefix(path, dir) {
			return fmt.Errorf("path %s outside directory %s", path, dir)
		}
		uripath := strings.TrimPrefix(filepath.ToSlash(filepath.Clean(path)), prefix)
		mhash, err = c.uploadToManifest(mhash, uripath, path, fi)
		return err
	})
	return mhash, err
}

func (c *client) uploadFile(file string, fi os.FileInfo) (manifestEntry, error) {
	hash, err := c.uploadFileContent(file, fi)
	m := manifestEntry{
		Hash:        hash,
		ContentType: mime.TypeByExtension(filepath.Ext(fi.Name())),
	}
	return m, err
}

func (c *client) uploadFileContent(file string, fi os.FileInfo) (string, error) {
	fd, err := os.Open(file)
	if err != nil {
		return "", err
	}
	defer fd.Close()
	log.Info("Uploading swarm content", "file", file, "bytes", fi.Size())
	return c.postRaw("application/octet-stream", fi.Size(), fd)
}

func (c *client) uploadManifest(m manifest) (string, error) {
	jsm, err := json.Marshal(m)
	if err != nil {
		panic(err)
	}
	log.Info("Uploading swarm manifest")
	return c.postRaw("application/json", int64(len(jsm)), ioutil.NopCloser(bytes.NewReader(jsm)))
}

func (c *client) uploadToManifest(mhash string, path string, fpath string, fi os.FileInfo) (string, error) {
	fd, err := os.Open(fpath)
	if err != nil {
		return "", err
	}
	defer fd.Close()
	log.Info("Uploading swarm content and path", "file", fpath, "bytes", fi.Size(), "path", path)
	req, err := http.NewRequest("PUT", c.api+"/bzz:/"+mhash+"/"+path, fd)
	if err != nil {
		return "", err
	}
	req.Header.Set("content-type", mime.TypeByExtension(filepath.Ext(fi.Name())))
	req.ContentLength = fi.Size()
	resp, err := http.DefaultClient.Do(req)
	if err != nil {
		return "", err
	}
	defer resp.Body.Close()
	if resp.StatusCode >= 400 {
		return "", fmt.Errorf("bad status: %s", resp.Status)
	}
	content, err := ioutil.ReadAll(resp.Body)
	return string(content), err
}

func (c *client) postRaw(mimetype string, size int64, body io.ReadCloser) (string, error) {
	req, err := http.NewRequest("POST", c.api+"/bzzr:/", body)
	if err != nil {
		return "", err
	}
	req.Header.Set("content-type", mimetype)
	req.ContentLength = size
	resp, err := http.DefaultClient.Do(req)
	if err != nil {
		return "", err
	}
	defer resp.Body.Close()
	if resp.StatusCode >= 400 {
		return "", fmt.Errorf("bad status: %s", resp.Status)
	}
	content, err := ioutil.ReadAll(resp.Body)
	return string(content), err
}

func (c *client) downloadManifest(mhash string) (manifest, error) {

	mroot := manifest{}
	req, err := http.NewRequest("GET", c.api+"/bzzr:/"+mhash, nil)
	if err != nil {
		return mroot, err
	}
	resp, err := http.DefaultClient.Do(req)
	if err != nil {
		return mroot, err
	}
	defer resp.Body.Close()

	if resp.StatusCode >= 400 {
		return mroot, fmt.Errorf("bad status: %s", resp.Status)

	}
	content, err := ioutil.ReadAll(resp.Body)

	err = json.Unmarshal(content, &mroot)
	if err != nil {
		return mroot, fmt.Errorf("Manifest %v is malformed: %v", mhash, err)
	}
	return mroot, err
}