Add interactive Template constructor, but not interactive Plugins

src/interactive.jl

@@ -1,8 +1,3 @@
-# const PLUGIN_TYPES = let
-#     leaves(T::Type) = isconcretetype(T) ? [T] : vcat(map(leaves, subtypes(T))...)
-#     leaves(Plugin)
-# end
-
 function Base.show(io::IO, ::MIME"text/plain", p::T) where T <: Plugin
     indent = get(io, :indent, 0)
     print(io, repeat(' ', indent), T)
@@ -21,6 +16,15 @@ else
     show_field(x::AbstractString) = repr(contractuser(x))
 end
 
+"""
+    interactive(::Type{T<:Plugin}) -> T
+
+Create a [`Plugin`](@ref) of type `T` interactively from user input.
+"""
+function interactive(::Type{T}) where T <: Plugin
+    return T()  # TODO
+end
+
 function Base.show(io::IO, m::MIME"text/plain", t::Template)
     println(io, "Template:")
     foreach(fieldnames(Template)) do n
@@ -36,3 +40,112 @@ function Base.show(io::IO, m::MIME"text/plain", t::Template)
         end
     end
 end
+
+leaves(T::Type) = isconcretetype(T) ? [T] : vcat(map(leaves, subtypes(T))...)
+
+function plugin_types()
+    Ts = leaves(Plugin)
+    # Hack both Documenter types into the list.
+    # Unfortunately there's no way to do this automatically,
+    # but it's unlikely for more parametric plugin types to exist.
+    push!(Ts, Documenter{TravisCI}, Documenter{GitLabCI})
+    return Ts
+end
+
+function Template(::Val{true}; kwargs...)
+    opts = Dict{Symbol, Any}(kwargs)
+
+    if !haskey(opts, :user)
+        opts[:user] = prompt(String, "Git hosting service username", defaultkw(:user))
+    end
+
+    if !haskey(opts, :host)
+        opts[:host] = prompt(String, "Git hosting service URL", defaultkw(:host))
+    end
+
+    if !haskey(opts, :authors)
+        opts[:authors] = prompt(String, "Package author(s)", defaultkw(:authors))
+    end
+
+    if !haskey(opts, :dir)
+        opts[:dir] = prompt(String, "Path to package parent directory", defaultkw(:dir))
+    end
+
+    if !haskey(opts, :julia)
+        opts[:julia] = prompt(VersionNumber, "Supported Julia version", defaultkw(:julia))
+    end
+
+    if !haskey(opts, :disable_defaults)
+        available = map(typeof, default_plugins())
+        opts[:disable_defaults] = select("Select defaults to disable:", available, [])
+    end
+
+    if !haskey(opts, :plugins)
+        # Don't offer any disabled plugins as options.
+        available = setdiff(sort(plugin_types(); by=string), opts[:disable_defaults])
+        initial = setdiff(map(typeof, default_plugins()), opts[:disable_defaults])
+        chosen = select("Select plugins", available, initial)
+        opts[:plugins] = map(interactive, chosen)
+    end
+
+    return Template(Val(false); opts...)
+end
+
+function prompt(::Type{String}, s::AbstractString, default; required::Bool=false)
+    default isa AbstractString && (default = contractuser(default))
+    default_display = required ? "REQUIRED" : repr(default)
+    print("$s [$default_display]: ")
+    input = strip(readline())
+    return if isempty(input) && required
+        println("This  option is required")
+        prompt(String, s, default; required=required)
+    elseif isempty(input)
+        default
+    else
+        input
+    end
+
+end
+
+function prompt(
+    ::Type{VersionNumber}, s::AbstractString, default::VersionNumber;
+    required::Bool=false,
+)
+    v = prompt(String, s, default; required=required)
+    return if v isa VersionNumber
+        v
+    else
+        startswith(v, "v") && (v = v[2:end])
+        v = replace(v, "\"" => "")
+        VersionNumber(v)
+    end
+end
+
+function prompt(::Type{Bool}, s::AbstractString, default::Bool; required::Bool=false)
+    b = prompt(String, s, default; required=required)
+    return uppercase(b) in ("Y", "YES", "T", "TRUE")
+end
+
+function prompt(::Type{Vector{String}}, s::AbstractString, default::Vector{<:AbstractString})
+    # TODO
+end
+
+# TODO: These can be made simpler when this is merged:
+# https://github.com/JuliaLang/julia/pull/30043
+
+select(s::AbstractString, xs::Vector, initial) = select(string, s, xs, initial)
+
+# Select any number of elements from a collection.
+function select(f::Function, s::AbstractString, xs::Vector, initial::Vector)
+    m = MultiSelectMenu(map(f, xs); pagesize=length(xs))
+    foreach(x -> push!(m.selected, findfirst(==(x), xs)), initial)
+    selection = request(s, m)
+    return map(i -> xs[i], collect(selection))
+end
+
+# Select one item frm oa collection.
+function select(f::Function, s::AbstractString, xs::Vector, _initial)
+    # Can't use the initial value yet.
+    selection = request(s, RadioMenu(map(f, xs)))
+    return xs[selection]
+end