package app

import _root_.util.JGitUtil.CommitInfo
import util.Directory._
import util.Implicits._
import _root_.util.ControlUtil._
import _root_.util._
import service._
import org.scalatra._
import java.io.File
import org.eclipse.jgit.api.Git
import org.eclipse.jgit.lib._
import org.apache.commons.io.FileUtils
import org.eclipse.jgit.treewalk._
import java.util.zip.{ZipEntry, ZipOutputStream}
import jp.sf.amateras.scalatra.forms._
import org.eclipse.jgit.dircache.DirCache
import org.eclipse.jgit.revwalk.RevCommit
import service.WebHookService.WebHookPayload

class RepositoryViewerController extends RepositoryViewerControllerBase
  with RepositoryService with AccountService with ActivityService with IssuesService with WebHookService
  with ReferrerAuthenticator with CollaboratorsAuthenticator

/**
 * The repository viewer.
 */
trait RepositoryViewerControllerBase extends ControllerBase {
  self: RepositoryService with AccountService with ActivityService with IssuesService with WebHookService
    with ReferrerAuthenticator with CollaboratorsAuthenticator =>

  case class EditorForm(
    branch: String,
    path: String,
    content: String,
    message: Option[String],
    charset: String,
    lineSeparator: String,
    newFileName: String,
    oldFileName: Option[String]
  )

  case class DeleteForm(
    branch: String,
    path: String,
    message: Option[String],
    fileName: String
  )

  val editorForm = mapping(
    "branch"        -> trim(label("Branch", text(required))),
    "path"          -> trim(label("Path", text())),
    "content"       -> trim(label("Content", text(required))),
    "message"       -> trim(label("Message", optional(text()))),
    "charset"       -> trim(label("Charset", text(required))),
    "lineSeparator" -> trim(label("Line Separator", text(required))),
    "newFileName"   -> trim(label("Filename", text(required))),
    "oldFileName"   -> trim(label("Old filename", optional(text())))
  )(EditorForm.apply)

  val deleteForm = mapping(
    "branch"   -> trim(label("Branch", text(required))),
    "path"     -> trim(label("Path", text())),
    "message"  -> trim(label("Message", optional(text()))),
    "fileName" -> trim(label("Filename", text(required)))
  )(DeleteForm.apply)

  /**
   * Returns converted HTML from Markdown for preview.
   */
  post("/:owner/:repository/_preview")(referrersOnly { repository =>
    contentType = "text/html"
    view.helpers.markdown(params("content"), repository,
      params("enableWikiLink").toBoolean,
      params("enableRefsLink").toBoolean)
  })

  /**
   * Displays the file list of the repository root and the default branch.
   */
  get("/:owner/:repository")(referrersOnly {
    fileList(_)
  })

  /**
   * Displays the file list of the specified path and branch.
   */
  get("/:owner/:repository/tree/*")(referrersOnly { repository =>
    val (id, path) = splitPath(repository, multiParams("splat").head)
    if(path.isEmpty){
      fileList(repository, id)
    } else {
      fileList(repository, id, path)
    }
  })

  /**
   * Displays the commit list of the specified resource.
   */
  get("/:owner/:repository/commits/*")(referrersOnly { repository =>
    val (branchName, path) = splitPath(repository, multiParams("splat").head)
    val page = params.get("page").flatMap(_.toIntOpt).getOrElse(1)

    using(Git.open(getRepositoryDir(repository.owner, repository.name))){ git =>
      JGitUtil.getCommitLog(git, branchName, page, 30, path) match {
        case Right((logs, hasNext)) =>
          repo.html.commits(if(path.isEmpty) Nil else path.split("/").toList, branchName, repository,
            logs.splitWith{ (commit1, commit2) =>
              view.helpers.date(commit1.commitTime) == view.helpers.date(commit2.commitTime)
            }, page, hasNext)
        case Left(_) => NotFound
      }
    }
  })

  get("/:owner/:repository/new/*")(collaboratorsOnly { repository =>
    val (branch, path) = splitPath(repository, multiParams("splat").head)
    repo.html.editor(branch, repository, if(path.length == 0) Nil else path.split("/").toList,
      None, JGitUtil.ContentInfo("text", None, Some("UTF-8")))
  })

  get("/:owner/:repository/edit/*")(collaboratorsOnly { repository =>
    val (branch, path) = splitPath(repository, multiParams("splat").head)

    using(Git.open(getRepositoryDir(repository.owner, repository.name))){ git =>
      val revCommit = JGitUtil.getRevCommitFromId(git, git.getRepository.resolve(branch))

      getPathObjectId(git, path, revCommit).map { objectId =>
        val paths = path.split("/")
        repo.html.editor(branch, repository, paths.take(paths.size - 1).toList, Some(paths.last),
          JGitUtil.getContentInfo(git, path, objectId))
      } getOrElse NotFound
    }
  })

  get("/:owner/:repository/remove/*")(collaboratorsOnly { repository =>
    val (branch, path) = splitPath(repository, multiParams("splat").head)
    using(Git.open(getRepositoryDir(repository.owner, repository.name))){ git =>
      val revCommit = JGitUtil.getRevCommitFromId(git, git.getRepository.resolve(branch))

      getPathObjectId(git, path, revCommit).map { objectId =>
        val paths = path.split("/")
        repo.html.delete(branch, repository, paths.take(paths.size - 1).toList, paths.last,
          JGitUtil.getContentInfo(git, path, objectId))
      } getOrElse NotFound
    }
  })

  post("/:owner/:repository/create", editorForm)(collaboratorsOnly { (form, repository) =>
    commitFile(repository, form.branch, form.path, Some(form.newFileName), None,
      StringUtil.convertLineSeparator(form.content, form.lineSeparator), form.charset,
      form.message.getOrElse(s"Create ${form.newFileName}"))

    redirect(s"/${repository.owner}/${repository.name}/blob/${form.branch}/${
      if(form.path.length == 0) form.newFileName else s"${form.path}/${form.newFileName}"
    }")
  })

  post("/:owner/:repository/update", editorForm)(collaboratorsOnly { (form, repository) =>
    commitFile(repository, form.branch, form.path, Some(form.newFileName), form.oldFileName,
      StringUtil.convertLineSeparator(form.content, form.lineSeparator), form.charset,
      if(form.oldFileName.exists(_ == form.newFileName)){
        form.message.getOrElse(s"Update ${form.newFileName}")
      } else {
        form.message.getOrElse(s"Rename ${form.oldFileName.get} to ${form.newFileName}")
      })

    redirect(s"/${repository.owner}/${repository.name}/blob/${form.branch}/${
      if(form.path.length == 0) form.newFileName else s"${form.path}/${form.newFileName}"
    }")
  })

  post("/:owner/:repository/remove", deleteForm)(collaboratorsOnly { (form, repository) =>
    commitFile(repository, form.branch, form.path, None, Some(form.fileName), "", "",
      form.message.getOrElse(s"Delete ${form.fileName}"))

    redirect(s"/${repository.owner}/${repository.name}/tree/${form.branch}${if(form.path.length == 0) "" else form.path}")
  })

  /**
   * Displays the file content of the specified branch or commit.
   */
  get("/:owner/:repository/blob/*")(referrersOnly { repository =>
    val (id, path) = splitPath(repository, multiParams("splat").head)
    val raw = params.get("raw").getOrElse("false").toBoolean

    using(Git.open(getRepositoryDir(repository.owner, repository.name))){ git =>
      val revCommit = JGitUtil.getRevCommitFromId(git, git.getRepository.resolve(id))
      getPathObjectId(git, path, revCommit).map { objectId =>
        if(raw){
          // Download
          defining(JGitUtil.getContentFromId(git, objectId, false).get){ bytes =>
            contentType = FileUtil.getContentType(path, bytes)
            bytes
          }
        } else {
          repo.html.blob(id, repository, path.split("/").toList, JGitUtil.getContentInfo(git, path, objectId),
            new JGitUtil.CommitInfo(revCommit), hasWritePermission(repository.owner, repository.name, context.loginAccount))
        }
      } getOrElse NotFound
    }
  })

  /**
   * Displays details of the specified commit.
   */
  get("/:owner/:repository/commit/:id")(referrersOnly { repository =>
    val id = params("id")

    using(Git.open(getRepositoryDir(repository.owner, repository.name))){ git =>
      defining(JGitUtil.getRevCommitFromId(git, git.getRepository.resolve(id))){ revCommit =>
        JGitUtil.getDiffs(git, id) match { case (diffs, oldCommitId) =>
          repo.html.commit(id, new JGitUtil.CommitInfo(revCommit),
            JGitUtil.getBranchesOfCommit(git, revCommit.getName),
            JGitUtil.getTagsOfCommit(git, revCommit.getName),
            repository, diffs, oldCommitId)
        }
      }
    }
  })

  /**
   * Displays branches.
   */
  get("/:owner/:repository/branches")(referrersOnly { repository =>
    using(Git.open(getRepositoryDir(repository.owner, repository.name))){ git =>
      // retrieve latest update date of each branch
      val branchInfo = repository.branchList.map { branchName =>
        val revCommit = git.log.add(git.getRepository.resolve(branchName)).setMaxCount(1).call.iterator.next
        (branchName, revCommit.getCommitterIdent.getWhen)
      }
      repo.html.branches(branchInfo, hasWritePermission(repository.owner, repository.name, context.loginAccount), repository)
    }
  })

  /**
   * Deletes branch.
   */
  get("/:owner/:repository/delete/*")(collaboratorsOnly { repository =>
    val branchName = multiParams("splat").head
    val userName   = context.loginAccount.get.userName
    if(repository.repository.defaultBranch != branchName){
      using(Git.open(getRepositoryDir(repository.owner, repository.name))){ git =>
        git.branchDelete().setForce(true).setBranchNames(branchName).call()
        recordDeleteBranchActivity(repository.owner, repository.name, userName, branchName)
      }
    }
    redirect(s"/${repository.owner}/${repository.name}/branches")
  })

  /**
   * Displays tags.
   */
  get("/:owner/:repository/tags")(referrersOnly {
    repo.html.tags(_)
  })

  /**
   * Download repository contents as an archive.
   */
  get("/:owner/:repository/archive/*")(referrersOnly { repository =>
    val name = multiParams("splat").head

    if(name.endsWith(".zip")){
      val revision = name.stripSuffix(".zip")
      val workDir = getDownloadWorkDir(repository.owner, repository.name, session.getId)
      if(workDir.exists){
        FileUtils.deleteDirectory(workDir)
      }
      workDir.mkdirs

      val zipFile = new File(workDir, repository.name + "-" +
        (if(revision.length == 40) revision.substring(0, 10) else revision).replace('/', '_') + ".zip")

      using(Git.open(getRepositoryDir(repository.owner, repository.name))){ git =>
        val revCommit = JGitUtil.getRevCommitFromId(git, git.getRepository.resolve(revision))
        using(new TreeWalk(git.getRepository)){ walk =>
          val reader   = walk.getObjectReader
          val objectId = new MutableObjectId

          using(new ZipOutputStream(new java.io.FileOutputStream(zipFile))){ out =>
            walk.addTree(revCommit.getTree)
            walk.setRecursive(true)

            while(walk.next){
              val name = walk.getPathString
              val mode = walk.getFileMode(0)
              if(mode == FileMode.REGULAR_FILE || mode == FileMode.EXECUTABLE_FILE){
                walk.getObjectId(objectId, 0)
                val entry = new ZipEntry(name)
                val loader = reader.open(objectId)
                entry.setSize(loader.getSize)
                out.putNextEntry(entry)
                loader.copyTo(out)
              }
            }
          }
        }
      }

      contentType = "application/octet-stream"
      response.setHeader("Content-Disposition", s"attachment; filename=${zipFile.getName}")
      zipFile
    } else {
      BadRequest
    }
  })

  get("/:owner/:repository/network/members")(referrersOnly { repository =>
    repo.html.forked(
      getRepository(
        repository.repository.originUserName.getOrElse(repository.owner),
        repository.repository.originRepositoryName.getOrElse(repository.name),
        context.baseUrl),
      getForkedRepositories(
        repository.repository.originUserName.getOrElse(repository.owner),
        repository.repository.originRepositoryName.getOrElse(repository.name)),
      repository)
  })

  private def splitPath(repository: service.RepositoryService.RepositoryInfo, path: String): (String, String) = {
    val id = repository.branchList.collectFirst {
      case branch if(path == branch || path.startsWith(branch + "/")) => branch
    } orElse repository.tags.collectFirst {
      case tag if(path == tag.name || path.startsWith(tag.name + "/")) => tag.name
    } getOrElse path.split("/")(0)

    (id, path.substring(id.length).stripPrefix("/"))
  }


  private val readmeFiles = view.helpers.renderableSuffixes.map(suffix => s"readme${suffix}") ++ Seq("readme.txt", "readme")

  /**
   * Provides HTML of the file list.
   *
   * @param repository the repository information
   * @param revstr the branch name or commit id(optional)
   * @param path the directory path (optional)
   * @return HTML of the file list
   */
  private def fileList(repository: RepositoryService.RepositoryInfo, revstr: String = "", path: String = ".") = {
    if(repository.commitCount == 0){
      repo.html.guide(repository, hasWritePermission(repository.owner, repository.name, context.loginAccount))
    } else {
      using(Git.open(getRepositoryDir(repository.owner, repository.name))){ git =>
        //val revisions = Seq(if(revstr.isEmpty) repository.repository.defaultBranch else revstr, repository.branchList.head)
        // get specified commit
        JGitUtil.getDefaultBranch(git, repository, revstr).map { case (objectId, revision) =>
          defining(JGitUtil.getRevCommitFromId(git, objectId)) { revCommit =>
            // get files
            val files = JGitUtil.getFileList(git, revision, path)
            val parentPath = if (path == ".") Nil else path.split("/").toList
            // process README.md or README.markdown
            val readme = files.find { file =>
              readmeFiles.contains(file.name.toLowerCase)
            }.map { file =>
              val path = (file.name :: parentPath.reverse).reverse
              path -> StringUtil.convertFromByteArray(JGitUtil.getContentFromId(
                Git.open(getRepositoryDir(repository.owner, repository.name)), file.id, true).get)
            }

            repo.html.files(revision, repository,
              if(path == ".") Nil else path.split("/").toList, // current path
              new JGitUtil.CommitInfo(revCommit), // latest commit
              files, readme, hasWritePermission(repository.owner, repository.name, context.loginAccount))
          }
        } getOrElse NotFound
      }
    }
  }

  private def commitFile(repository: service.RepositoryService.RepositoryInfo,
                         branch: String, path: String, newFileName: Option[String], oldFileName: Option[String],
                         content: String, charset: String, message: String) = {

    val newPath = newFileName.map { newFileName => if(path.length == 0) newFileName else s"${path}/${newFileName}" }
    val oldPath = oldFileName.map { oldFileName => if(path.length == 0) oldFileName else s"${path}/${oldFileName}" }

    LockUtil.lock(s"${repository.owner}/${repository.name}"){
      using(Git.open(getRepositoryDir(repository.owner, repository.name))){ git =>
        val loginAccount = context.loginAccount.get
        val builder  = DirCache.newInCore.builder()
        val inserter = git.getRepository.newObjectInserter()
        val headName = s"refs/heads/${branch}"
        val headTip  = git.getRepository.resolve(s"refs/heads/${branch}")

        JGitUtil.processTree(git, headTip){ (path, tree) =>
          if(!newPath.exists(_ == path) && !oldPath.exists(_ == path)){
            builder.add(JGitUtil.createDirCacheEntry(path, tree.getEntryFileMode, tree.getEntryObjectId))
          }
        }

        newPath.foreach { newPath =>
          builder.add(JGitUtil.createDirCacheEntry(newPath, FileMode.REGULAR_FILE,
            inserter.insert(Constants.OBJ_BLOB, content.getBytes(charset))))
        }
        builder.finish()

        val commitId = JGitUtil.createNewCommit(git, inserter, headTip, builder.getDirCache.writeTree(inserter),
          loginAccount.fullName, loginAccount.mailAddress, message)

        inserter.flush()
        inserter.release()

        // update refs
        val refUpdate = git.getRepository.updateRef(headName)
        refUpdate.setNewObjectId(commitId)
        refUpdate.setForceUpdate(false)
        refUpdate.setRefLogIdent(new PersonIdent(loginAccount.fullName, loginAccount.mailAddress))
        //refUpdate.setRefLogMessage("merged", true)
        refUpdate.update()

        // record activity
        recordPushActivity(repository.owner, repository.name, loginAccount.userName, branch,
          List(new CommitInfo(JGitUtil.getRevCommitFromId(git, commitId))))

        // close issue by commit message
        closeIssuesFromMessage(message, loginAccount.userName, repository.owner, repository.name)

        // call web hook
        val commit = new JGitUtil.CommitInfo(JGitUtil.getRevCommitFromId(git, commitId))
        getWebHookURLs(repository.owner, repository.name) match {
          case webHookURLs if(webHookURLs.nonEmpty) =>
            for(ownerAccount <- getAccountByUserName(repository.owner)){
              callWebHook(repository.owner, repository.name, webHookURLs,
                WebHookPayload(git, loginAccount, headName, repository, List(commit), ownerAccount))
            }
          case _ =>
        }
      }
    }
  }

  private def getPathObjectId(git: Git, path: String, revCommit: RevCommit): Option[ObjectId] = {
    @scala.annotation.tailrec
    def _getPathObjectId(path: String, walk: TreeWalk): Option[ObjectId] = walk.next match {
      case true if(walk.getPathString == path) => Some(walk.getObjectId(0))
      case true  => _getPathObjectId(path, walk)
      case false => None
    }

    using(new TreeWalk(git.getRepository)){ treeWalk =>
      treeWalk.addTree(revCommit.getTree)
      treeWalk.setRecursive(true)
      _getPathObjectId(path, treeWalk)
    }
  }

}