(.module:
  [library
   [lux "*"
    [program {"+" [program:]}]
    ["." type ("#\." equivalence)]
    ["." debug]
    [abstract
     ["." monad {"+" [do]}]
     ["." enum]]
    [control
     [pipe {"+" [when> new>]}]
     ["." maybe]
     ["." try {"+" [Try]}]
     ["." exception {"+" [exception:]}]
     ["." io {"+" [IO io]}]
     ["." function]]
    [data
     ["." product]
     [format
      ["md" markdown {"+" [Markdown Span Block]}]]
     ["." text ("#\." equivalence)
      ["%" format {"+" [format]}]
      [encoding
       ["." utf8]]]
     [collection
      ["." sequence {"+" [Sequence]} ("#\." functor)]
      ["." list ("#\." functor mix)]]]
    [math
     [number
      ["n" nat]]]
    ["." meta
     ["." annotation]]
    [world
     ["." file]]]]
  ... This was added to make sure that all tested modules are picked up
  ... and their documentation is generated.
  [test/lux {"+" []}])

... (def: parameter_name_options "abcdefghijklmnopqrstuvwxyz")
... (def: parameter_name_options_count (text.size parameter_name_options))

... (def: (parameter_type_name id)
...   (-> Nat Text)
...   (case (text.char id ..parameter_name_options)
...     (#.Some char)
...     (text.of_char char)

...     #.None
...     (format (parameter_type_name (n./ parameter_name_options_count id))
...             (parameter_type_name (n.% parameter_name_options_count id)))))

... (def: type_variable_names
...   (Sequence Text)
...   (|> 0 (sequence.iterations ++) (sequence\each parameter_type_name)))

... (template [<name> <partition>]
...   [(def: (<name> id)
...      (-> Nat Bit)
...      (<partition> id))]

...   [type_function? n.even?]
...   [type_parameter? n.odd?]
...   )

... (def: (parameter_id level id)
...   (-> Nat Nat Nat)
...   (n.- (n./ 2 id) level))

... (def: (parameter_name [type_function_name type_function_arguments] level id)
...   (-> [Text (List Text)] Nat Nat Text)
...   (if (type_parameter? id)
...     (let [parameter_id (..parameter_id level id)]
...       (case (list.item parameter_id type_function_arguments)
...         (#.Some found)
...         found

...         _
...         (|> type_variable_names
...             (sequence.only (function (_ var_name)
...                              (not (list.member? text.equivalence type_function_arguments var_name))))
...             (sequence.item parameter_id))))      
...     type_function_name))

... (def: (level_parameters offset level)
...   (-> Nat Nat (List Text))
...   (if (n.= 0 level)
...     (list)
...     (|> level
...         --
...         (enum.range n.enum 0)
...         (list\each (|>> (n.+ (++ offset)) parameter_type_name)))))

... (def: (prefix_lines prefix lines)
...   (-> Text Text Text)
...   (|> lines
...       (text.all_split_by text.new_line)
...       (list\each (|>> (format prefix)))
...       (text.interposed text.new_line)))

... (def: (pprint_type_definition level type_function_info tags module interface? recursive_type? type)
...   (-> Nat [Text (List Text)] (List Name) Text Bit Bit Type Text)
...   (case tags
...     (^ (list [_ single_tag]))
...     (if interface?
...       (format "(: " (pprint_type_definition level type_function_info #.None module interface? recursive_type? type) text.new_line "   " single_tag ")")
...       (format "(Record [#" single_tag " " (pprint_type_definition level type_function_info #.None module interface? recursive_type? type) "])"))

...     _
...     (case [recursive_type? type]
...       [_ (#.Primitive name params)]
...       (case params
...         #.End
...         (format "(primitive " (%.text name) ")")

...         _
...         (format "(primitive " (%.text name) " " (|> params (list\each (pprint_type_definition level type_function_info #.None module interface? recursive_type?)) (text.interposed " ")) ")"))

...       [_ (#.Sum _)]
...       (let [members (type.flat_variant type)]
...         (case tags
...           #.End
...           (format "(Or "
...                   (|> members
...                       (list\each (pprint_type_definition level type_function_info #.None module interface? recursive_type?))
...                       (text.interposed " "))
...                   ")")

...           _
...           (|> members
...               (list.zipped/2 tags)
...               (list\each (function (_ [[_ t_name] type])
...                            (case type
...                              (#.Product _)
...                              (let [types (type.flat_tuple type)]
...                                (format "(#" t_name " "
...                                        (|> types
...                                            (list\each (pprint_type_definition level type_function_info #.None module interface? recursive_type?))
...                                            (text.interposed " "))
...                                        ")"))

...                              _
...                              (format "(#" t_name " " (pprint_type_definition level type_function_info #.None module interface? recursive_type? type) ")"))))
...               (text.interposed text.new_line))))

...       [_ (#.Product _)]
...       (let [members (type.flat_tuple type)]
...         (case tags
...           #.End
...           (format "[" (|> members (list\each (pprint_type_definition level type_function_info #.None module interface? recursive_type?)) (text.interposed " ")) "]")

...           _
...           (let [member_docs (|> members
...                                 (list.zipped/2 tags)
...                                 (list\each (function (_ [[_ t_name] type])
...                                              (if interface?
...                                                (format "(: " (pprint_type_definition level type_function_info #.None module interface? recursive_type? type) text.new_line "   "  t_name ")")
...                                                (format "#" t_name " " (pprint_type_definition level type_function_info #.None module interface? recursive_type? type)))))
...                                 (text.interposed (format text.new_line " ")))]
...             (if interface?
...               member_docs
...               (format "(Record [" member_docs "])")))))

...       [_ (#.Function input output)]
...       (let [[ins out] (type.flat_function type)]
...         (format  "(-> " (|> ins (list\each (pprint_type_definition level type_function_info #.None module interface? recursive_type?)) (text.interposed " "))
...                  " "
...                  (pprint_type_definition level type_function_info #.None module interface? recursive_type? out)
...                  ")"))

...       [_ (#.Parameter idx)]
...       (parameter_name type_function_info level idx)

...       (^template [<tag> <pre> <post>]
...         [[_ (<tag> id)]
...          (format <pre> (%.nat id) <post>)])
...       ([#.Var "⌈v:" "⌋"]
...        [#.Ex  "⟨e:" "⟩"])

...       (^template [<tag> <name> <flat>]
...         [[_ (<tag> _)]
...          (let [[level' body] (<flat> type)
...                args (level_parameters level level')
...                body_doc (pprint_type_definition (n.+ level level') type_function_info tags module interface? recursive_type? body)]
...            (format "(" <name> " " "[" (text.interposed " " args) "]"
...                    (case tags
...                      #.End
...                      (format " " body_doc)

...                      _
...                      (format text.new_line (prefix_lines "  " body_doc)))
...                    ")"))])
...       ([#.UnivQ "All" type.flat_univ_q]
...        [#.ExQ   "Ex"  type.flat_ex_q])

...       [true (#.Apply (#.Parameter 1) (#.Parameter 0))]
...       (product.left type_function_info)

...       [_ (#.Apply param fun)]
...       (let [[type_func type_arguments] (type.flat_application type)]
...         (format  "(" (pprint_type_definition level type_function_info tags module interface? recursive_type? type_func) " " (|> type_arguments (list\each (pprint_type_definition level type_function_info #.None module interface? recursive_type?)) (text.interposed " ")) ")"))

...       [_ (#.Named [_module _name] type)]
...       (if (text\= module _module)
...         _name
...         (%.name [_module _name]))
...       )))

... (def: (pprint_type level type_function_name module type)
...   (-> Nat Text Text Type Text)
...   (case type
...     (#.Primitive name params)
...     (case params
...       #.End
...       (format "(primitive " (%.text name) ")")

...       _
...       (format "(primitive " (%.text name) " " (|> params (list\each (pprint_type level type_function_name module)) (text.interposed " ")) ")"))

...     (#.Sum _)
...     (let [members (type.flat_variant type)]
...       (format "(Or " (|> members (list\each (pprint_type level type_function_name module)) (text.interposed " ")) ")"))

...     (#.Product _)
...     (let [members (type.flat_tuple type)]
...       (format "[" (|> members (list\each (pprint_type level type_function_name module)) (text.interposed " ")) "]"))

...     (#.Function input output)
...     (let [[ins out] (type.flat_function type)]
...       (format  "(-> "
...                (|> ins (list\each (pprint_type level type_function_name module)) (text.interposed " "))
...                " "
...                (pprint_type level type_function_name module out)
...                ")"))

...     (#.Parameter idx)
...     (parameter_name [type_function_name (list)] level idx)

...     (^template [<tag> <pre> <post>]
...       [(<tag> id)
...        (format <pre> (%.nat id) <post>)])
...     ([#.Var "⌈" "⌋"]
...      [#.Ex  "⟨" "⟩"])

...     (^template [<tag> <name> <flat>]
...       [(<tag> _)
...        (let [[level' body] (<flat> type)
...              args (level_parameters level level')
...              body_doc (pprint_type (n.+ level level') type_function_name module body)]
...          (format "(" <name> " " "[" (|> args (text.interposed " ")) "]"
...                  (format " " body_doc)
...                  ")"))])
...     ([#.UnivQ "All" type.flat_univ_q]
...      [#.ExQ   "Ex"  type.flat_ex_q])

...     (#.Apply param fun)
...     (let [[type_func type_arguments] (type.flat_application type)]
...       (format  "(" (pprint_type level type_function_name module type_func) " " (|> type_arguments (list\each (pprint_type level type_function_name module)) (text.interposed " ")) ")"))

...     (#.Named [_module _name] type)
...     (if (text\= module _module)
...       _name
...       (%.name [_module _name]))
...     ))

... (type: (Mutation a)
...   (-> a a))

... (type: Value
...   [Text Code Type])

... (type: Organization
...   (Record
...    [#types (List Value)
...     #macros (List [Text Code])
...     #implementations (List Value)
...     #values (List Value)]))

... (def: (lux_module? module_name)
...   (-> Text Bit)
...   (let [prefix (format .prelude_module "/")]
...     (or (text\= .prelude_module module_name)
...         (text.starts_with? prefix module_name))))

... (def: (add_definition [name [exported? def_type def_annotations def_value]] organization)
...   (-> [Text Definition] Organization Organization)
...   (cond (type\= .Type def_type)
...         (revised@ #types
...                   (: (Mutation (List Value))
...                      (|>> (#.Item [name def_annotations (:as Type def_value)])))
...                   organization)

...         (type\= .Macro def_type)
...         (revised@ #macros
...                   (: (Mutation (List [Text Code]))
...                      (|>> (#.Item [name def_annotations])))
...                   organization)

...         (annotation.implementation? def_annotations)
...         (revised@ #implementations
...                   (: (Mutation (List Value))
...                      (|>> (#.Item [name def_annotations def_type])))
...                   organization)

...         ... else
...         (revised@ #values
...                   (: (Mutation (List Value))
...                      (|>> (#.Item [name def_annotations def_type])))
...                   organization)))

... (def: name_sort
...   (All (_ r) (-> [Text r] [Text r] Bit))
...   (let [text\< (\ text.order <)]
...     (function (_ [n1 _] [n2 _])
...       (text\< n1 n2))))

... (def: (organize_definitions defs)
...   (-> (List [Text Definition]) Organization)
...   (let [init [#types (list)
...               #macros (list)
...               #implementations (list)
...               #values (list)]]
...     (|> (list\mix add_definition init defs)
...         (revised@ #types (list.sorted name_sort))
...         (revised@ #macros (list.sorted name_sort))
...         (revised@ #implementations (list.sorted name_sort))
...         (revised@ #values (list.sorted name_sort)))))

(def: (unravel_type_func level type)
  (-> Nat Type Type)
  (if (n.> 0 level)
    (case type
      (#.UnivQ _env _type)
      (unravel_type_func (-- level) _type)

      _
      type)
    type))

(def: (unrecurse_type type)
  (-> Type Type)
  (case type
    (#.Apply _ (#.UnivQ _env _type))
    _type

    _
    type))

(exception: .public (anonymous_type_definition {type Type})
  (exception.report
   ["Type" (%.type type)]))

(def: (document_type module type def_annotations)
  (-> Text Type Code (Meta (Markdown Block)))
  (case type
    (#.Named type_name type)
    (do meta.monad
      [tags (meta.tags_of type_name)
       .let [[_ _name] type_name
             recursive_type? (annotation.recursive_type? def_annotations)
             type_arguments (annotation.type_arguments def_annotations)
             interface? (annotation.interface? def_annotations)
             usage (case type_arguments
                     #.End
                     _name

                     _
                     (format "(" (text.interposed " " (list& _name type_arguments)) ")"))
             nesting (list.size type_arguments)]]
      (in (md.code (format (if interface? "(interface: " "(type: ")
                           (if recursive_type? "#rec " "")
                           usage text.new_line
                           (|> type
                               (unravel_type_func nesting)
                               (when> [(new> recursive_type? [])] [unrecurse_type])
                               (pprint_type_definition (-- nesting) [_name type_arguments] (maybe.else (list) tags) module interface? recursive_type?)
                               (text.all_split_by text.new_line)
                               (list\each (|>> (format "  ")))
                               (text.interposed text.new_line))
                           ")"))))

    _
    (meta.failure (exception.error anonymous_type_definition type))))

(def: (document_types module types)
  (-> Text (List Value) (Meta (Markdown Block)))
  (do {! meta.monad}
    [type_docs (monad.each !
                           (: (-> Value (Meta (Markdown Block)))
                              (function (_ [name def_annotations type])
                                (do meta.monad
                                  [.let [?doc (annotation.documentation def_annotations)]
                                   type_code (document_type module type def_annotations)]
                                  (in ($_ md.then
                                          (md.heading/3 name)
                                          (case ?doc
                                            (#.Some doc)
                                            (md.paragraph (md.text doc))

                                            _
                                            md.empty)
                                          type_code)))))
                           types)]
    (in (list\mix (function.flipped md.then)
                  (md.heading/2 "Types")
                  type_docs))))

... (def: (document_macros module_name names)
...   (-> Text (List [Text Code]) (Markdown Block))
...   (|> names
...       (list\each (: (-> [Text Code] (Markdown Block))
...                     (function (_ [name def_annotations])
...                       ($_ md.then
...                           (md.heading/3 name)
...                           (<| (: (Markdown Block))
...                               (maybe.else md.empty)
...                               (do maybe.monad
...                                 [documentation (annotation.documentation def_annotations)]
...                                 (in (md.code documentation))))))))
...       (list\mix (function.flipped md.then)
...                 (md.heading/2 "Macros"))))

... (template [<singular> <plural> <header>]
...   [(def: (<singular> module type)
...      (-> Text Type (Markdown Block))
...      (md.code (pprint_type (-- 0) "?" module type)))

...    (def: (<plural> module values)
...      (-> Text (List Value) (Markdown Block))
...      (|> values
...          (list\each (function (_ [name def_annotations value_type])
...                       (let [?doc (annotation.documentation def_annotations)
...                             usage (case (annotation.function_arguments def_annotations)
...                                     #.End
...                                     name

...                                     args
...                                     (format "(" (text.interposed " " (list& name args)) ")"))]
...                         ($_ md.then
...                             (md.heading/3 usage)
...                             (case ?doc
...                               (#.Some doc)
...                               (md.code doc)

...                               _
...                               md.empty)
...                             (<singular> module value_type)))))
...          (list\mix (function.flipped md.then)
...                    (md.heading/2 <header>))))]

...   [document_implementation document_implementations "Implementations"]
...   [document_value     document_values     "Values"]
...   )

... (def: (enclose_lines pre+post block)
...   (-> [Text Text] Text Text)
...   (|> block
...       (text.all_split_by text.new_line)
...       (list\each (text.enclosed pre+post))
...       (text.interposed text.new_line)))

... (def: (document_module [[module_name module] organization])
...   (-> [[Text Module] Organization] (Meta [Text (Markdown Block)]))
...   (do meta.monad
...     [.let [(^slots [#types #macros #implementations #values]) organization
...            annotations (|> module
...                            (value@ #.module_annotations)
...                            (maybe.else (' {}))
...                            annotation.documentation)
...            description (case annotations
...                          (#.Some doc_text)
...                          (md.quote (md.paragraph (md.text doc_text)))

...                          #.None
...                          md.empty)
...            empty_block (: (Markdown Block) md.empty)]
...      types_documentation (if (list.empty? types)
...                            (in empty_block)
...                            (document_types module_name types))
...      .let [documentation ($_ md.then
...                              types_documentation
...                              (if (list.empty? macros) empty_block (document_macros module_name macros))
...                              (if (list.empty? implementations) empty_block (document_implementations module_name implementations))
...                              (if (list.empty? values) empty_block (document_values module_name values)))]]
...     (in [module_name
...          ($_ md.then
...              (md.heading/1 module_name)
...              description
...              documentation)])))

... (exception: .public (io_error {error Text})
...   error)

... (def: (save_documentation! [module_name documentation])
...   (-> [Text (Markdown Block)] (IO Any))
...   (let [path (format (text.replaced "/" "_" module_name) ".md")]
...     (do io.monad
...       [outcome (\ file.default write (\ utf8.codec encoded (md.markdown documentation)) path)]
...       (in (case outcome
...             (#try.Failure error)
...             (debug.log! (exception.error io_error error))

...             (#try.Success _)
...             [])))))

... (macro: (gen_documentation! _)
...   (do {! meta.monad}
...     [all_modules meta.modules
...      .let [lux_modules (|> all_modules
...                            (list.only (function.composite lux_module? product.left))
...                            (list.sorted name_sort))]
...      lux_exports (monad.each ! (function.composite meta.exports product.left)
...                              lux_modules)
...      module_documentation (|> (list\each organize_definitions lux_exports)
...                               (list.zipped/2 lux_modules)
...                               (monad.each ! document_module))
...      .let [_ (io.run! (monad.each io.monad save_documentation! module_documentation))]]
...     (in (list))))

... (gen_documentation!)

... (program: args
...   (io (debug.log! "Done!")))