1 files changed, 107 insertions, 0 deletions
diff --git a/src/main/scala/completion/Bash.scala b/src/main/scala/completion/Bash.scala
new file mode 100644
index 0000000..0ba3440
--- /dev/null
+++ b/src/main/scala/completion/Bash.scala
@@ -0,0 +1,107 @@
+package cmd
+package completion
+
+object Bash {
+
+  private def addCommands(command: Command): String = {
+    command.commands.map(c => s"""commands+=("$c")\n""").mkString
+  }
+
+  private def addFlags(command: Command): String = {
+    command.options.map { opt =>
+      val extra = if (opt.argumentRequired) "=" else ""
+      val short = opt.short.map(c => s"""flags+=("-${c}")""").getOrElse("")
+      s"""|flags+=("--${opt.long}$extra")
+          |$short
+          |""".stripMargin
+    }.mkString
+  }
+
+  private def commandBlocks(previous: String,
+                            commands: Set[Command]): String = {
+    def block(previous: String, command: Command): String = {
+      s"""_${previous}_${command.name}() {
+         |    ${addCommands(command)}
+         |    ${addFlags(command)}
+         |    true
+         |}
+         |""".stripMargin
+    }
+
+    if (commands.isEmpty) {
+      ""
+    } else {
+      commands.map { cmd =>
+        block(previous, cmd) + commandBlocks(cmd.name, cmd.commands)
+      }.mkString
+    }
+  }
+
+  def completion(command: Command) = {
+    val name = command.name
+
+    s"""__${name}_contains_word() {
+       |    local word="$$1"; shift
+       |    for w in "$$@"; do
+       |        [[ $$w = "$$word" ]] && return 0
+       |    done
+       |    return 1
+       |}
+       |
+       |__${name}_handle_reply() {
+       |    case "$$cur" in
+       |        -*)
+       |            COMPREPLY=( $$(compgen -W "$${flags[*]}" -- "$$cur") )
+       |            if [[ $${#COMPREPLY[@]} -eq 1 ]] && [[ $${COMPREPLY[0]} == *= ]]; then
+       |                compopt -o nospace
+       |            else
+       |                compopt +o nospace
+       |            fi
+       |            ;;
+       |        *)
+       |            COMPREPLY=( $$(compgen -W "$${commands[*]}" -- "$$cur") )
+       |            ;;
+       |    esac
+       |}
+       |
+       |__${name}_handle_word() {
+       |    if [[ $$c -ge $$cword ]]; then
+       |        __${name}_handle_reply
+       |        return
+       |    fi
+       |    if __${name}_contains_word "$${words[c]}" "$${commands[@]}"; then
+       |        local next_command="$${last_command}_$${words[c]}"
+       |        last_command="$$next_command"
+       |        commands=()
+       |        flags=()
+       |        $$next_command
+       |    fi
+       |    c=$$((c+1))
+       |    __${name}_handle_word
+       |}
+       |
+       |${commandBlocks(name, command.commands)}
+       |
+       |__${name}_start() {
+       |    local words=("$${COMP_WORDS[@]}")
+       |    local cword="$$COMP_CWORD"
+       |    local cur="$${COMP_WORDS[COMP_CWORD]}"
+       |    local c=0
+       |    COMPREPLY=()
+       |
+       |    local last_command="_${name}"
+       |    local commands=()
+       |    local flags=()
+       |
+       |    ${addCommands(command)}
+       |    ${addFlags(command)}
+       |
+       |    __${name}_handle_word
+       |
+       |    return 0
+       |}
+       |complete -o default -F __${name}_start ${name}
+       |""".stripMargin
+  }
+
+}