package gitbucket.core.plugin

import gitbucket.core.controller.Context
import gitbucket.core.service.RepositoryService.RepositoryInfo

/**
 * The base trait of suggestion providers which supplies completion proposals in some text areas.
 */
trait SuggestionProvider {

  /**
   * The identifier of this suggestion provider.
   * You must specify the unique identifier in the all suggestion providers.
   */
  val id: String

  /**
   * The trigger of this suggestion provider. When user types this character, the proposal list would be displayed.
   * Also this is used as the prefix of the replaced string.
   */
  val prefix: String

  /**
   * The suffix of the replaced string. The default is `" "`.
   */
  val suffix: String = " "

  /**
   * Which contexts is this suggestion provider enabled. Currently, available contexts are `"issues"` and `"wiki"`.
   */
  val context: Seq[String]

  /**
   * If this suggestion provider has static proposal list, override this method to return it.
   *
   * The returned sequence is rendered as follows:
   * <pre>
   * [
   *   {
   *     "label" -> "value1",
   *     "value" -> "value1"
   *   },
   *   {
   *     "label" -> "value2",
   *     "value" -> "value2"
   *   },
   * ]
   * </pre>
   *
   * Each element can be accessed as `option` in `template()` or `replace()` method.
   */
  def values(repository: RepositoryInfo): Seq[String] = Nil

  /**
   * If this suggestion provider has static proposal list, override this method to return it.
   *
   * If your proposals have label and value, use this method instead of `values()`.
   * The first element of tuple is used as a value, and the second element is used as a label.
   *
   * The returned sequence is rendered as follows:
   * <pre>
   * [
   *   {
   *     "label" -> "label1",
   *     "value" -> "value1"
   *   },
   *   {
   *     "label" -> "label2",
   *     "value" -> "value2"
   *   },
   * ]
   * </pre>
   *
   * Each element can be accessed as `option` in `template()` or `replace()` method.
   */
  def options(repository: RepositoryInfo): Seq[(String, String)] = values(repository).map { value =>
    (value, value)
  }

  /**
   * JavaScript fragment to generate a label of completion proposal. The default is: `option.label`.
   */
  def template(implicit context: Context): String = "option.label"

  /**
   * JavaScript fragment to generate a replaced value of completion proposal. The default is: `option.value`
   */
  def replace(implicit context: Context): String = "option.value"

  /**
   * If this suggestion provider needs some additional process to assemble the proposal list (e.g. It need to use Ajax
   * to get a proposal list from the server), then override this method and return any JavaScript code.
   */
  def additionalScript(implicit context: Context): String = ""

}

class UserNameSuggestionProvider extends SuggestionProvider {
  override val id: String = "user"
  override val prefix: String = "@"
  override val context: Seq[String] = Seq("issues")
  override def additionalScript(implicit context: Context): String =
    s"""$$.get('${context.path}/_user/proposals', { query: '', user: true, group: false }, function (data) { user = data.options; });"""
}