// Copyright 2013 gopm authors.
//
// Licensed under the Apache License, Version 2.0 (the "License"): you may
// not use this file except in compliance with the License. You may obtain
// a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
// WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
// License for the specific language governing permissions and limitations
// under the License.

package doc

import (
	"archive/tar"
	"bytes"
	"compress/gzip"
	"errors"
	"io"
	"net/http"
	"os"
	"path"
	"regexp"
	"strings"

	"github.com/Unknwon/com"
	"github.com/codegangsta/cli"

	//"github.com/gpmgo/gopm/log"
)

var (
	bitbucketPattern = regexp.MustCompile(`^bitbucket\.org/(?P<owner>[a-z0-9A-Z_.\-]+)/(?P<repo>[a-z0-9A-Z_.\-]+)(?P<dir>/[a-z0-9A-Z_.\-/]*)?$`)
	bitbucketEtagRe  = regexp.MustCompile(`^(hg|git)-`)
)

// getBitbucketDoc downloads tarball from bitbucket.org.
func getBitbucketDoc(client *http.Client, match map[string]string, installRepoPath string, nod *Node, ctx *cli.Context) ([]string, error) {
	// Check version control.
	if m := bitbucketEtagRe.FindStringSubmatch(nod.Value); m != nil {
		match["vcs"] = m[1]
	} else {
		var repo struct {
			Scm string
		}
		if err := com.HttpGetJSON(client, com.Expand("https://api.bitbucket.org/1.0/repositories/{owner}/{repo}", match), &repo); err != nil {
			return nil, err
		}
		match["vcs"] = repo.Scm
	}

	if nod.Type == BRANCH {
		if len(nod.Value) == 0 {
			match["commit"] = defaultTags[match["vcs"]]
		} else {
			match["commit"] = nod.Value
		}
	}

	if nod.IsGetDeps {
		if nod.Type == COMMIT {
			tags := make(map[string]string)
			for _, nodeType := range []string{"branches", "tags"} {
				var nodes map[string]struct {
					Node string
				}
				if err := com.HttpGetJSON(client, com.Expand("https://api.bitbucket.org/1.0/repositories/{owner}/{repo}/{0}", match, nodeType), &nodes); err != nil {
					return nil, err
				}
				for t, n := range nodes {
					tags[t] = n.Node
				}
			}

			// Check revision tag.
			var err error
			match["tag"], match["commit"], err = bestTag(tags, defaultTags[match["vcs"]])
			if err != nil {
				return nil, err
			}

			nod.Value = match["commit"]
		}
	} else {
		// Check downlaod type.
		switch nod.Type {
		case TAG, COMMIT, BRANCH:
			match["commit"] = nod.Value
		default:
			return nil, errors.New("Unknown node type: " + nod.Type)
		}
	}

	// We use .tar.gz here.
	// zip : https://bitbucket.org/{owner}/{repo}/get/{commit}.zip
	// tarball : https://bitbucket.org/{owner}/{repo}/get/{commit}.tar.gz

	// Downlaod archive.
	p, err := com.HttpGetBytes(client, com.Expand("https://bitbucket.org/{owner}/{repo}/get/{commit}.tar.gz", match), nil)
	if err != nil {
		return nil, err
	}

	var installPath string
	if nod.ImportPath == nod.DownloadURL {
		suf := "." + nod.Value
		if len(suf) == 1 {
			suf = ""
		}
		projectPath := com.Expand("bitbucket.org/{owner}/{repo}", match)
		installPath = installRepoPath + "/" + projectPath + suf
		nod.ImportPath = projectPath
	} else {
		installPath = installRepoPath + "/" + nod.ImportPath
	}

	// Remove old files.
	os.RemoveAll(installPath + "/")
	os.MkdirAll(installPath+"/", os.ModePerm)

	gzr, err := gzip.NewReader(bytes.NewReader(p))
	if err != nil {
		return nil, err
	}
	defer gzr.Close()

	tr := tar.NewReader(gzr)

	var autoPath string // Auto path is the root path that generated by bitbucket.org.
	// Get source file data.
	dirs := make([]string, 0, 5)
	for {
		h, err := tr.Next()
		if err == io.EOF {
			break
		} else if err != nil {
			return nil, err
		}

		fn := h.Name

		// In case that we find directory, usually we should not.
		if strings.HasSuffix(fn, "/") {
			continue
		}

		// Check root path.
		if len(autoPath) == 0 {
			autoPath = fn[:strings.Index(fn, "/")]
		}
		absPath := strings.Replace(fn, autoPath, installPath, 1)

		// Create diretory before create file.
		dir := path.Dir(absPath)
		if !checkDir(dir, dirs) && !(!ctx.Bool("example") && strings.Contains(absPath, "example")) {
			dirs = append(dirs, dir)
			os.MkdirAll(dir+"/", os.ModePerm)
		}

		// Get data from archive.
		fbytes := make([]byte, h.Size)
		if _, err := io.ReadFull(tr, fbytes); err != nil {
			return nil, err
		}

		_, err = com.SaveFile(absPath, fbytes)
		if err != nil {
			return nil, err
		}

		// Set modify time.
		os.Chtimes(absPath, h.AccessTime, h.ModTime)
	}

	var imports []string

	// Check if need to check imports.
	if nod.IsGetDeps {
		for _, d := range dirs {
			importPkgs, err := CheckImports(d+"/", match["importPath"], nod)
			if err != nil {
				return nil, err
			}
			imports = append(imports, importPkgs...)
		}
	}

	return imports, err
}

// checkDir checks if current directory has been saved.
func checkDir(dir string, dirs []string) bool {
	for _, d := range dirs {
		if dir == d {
			return true
		}
	}
	return false
}