(* {{{ COPYING *(

     This file is part of Merlin, an helper for ocaml editors

     Copyright (C) 2013 - 2015  Frédéric Bour  <frederic.bour(_)lakaban.net>
                                Thomas Refis  <refis.thomas(_)gmail.com>
                                Simon Castellan  <simon.castellan(_)iuwt.fr>

     Permission is hereby granted, free of charge, to any person obtaining a
     copy of this software and associated documentation files (the "Software"),
     to deal in the Software without restriction, including without limitation the
     rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
     sell copies of the Software, and to permit persons to whom the Software is
     furnished to do so, subject to the following conditions:

     The above copyright notice and this permission notice shall be included in
     all copies or substantial portions of the Software.

     The Software is provided "as is", without warranty of any kind, express or
     implied, including but not limited to the warranties of merchantability,
     fitness for a particular purpose and noninfringement. In no event shall
     the authors or copyright holders be liable for any claim, damages or other
     liability, whether in an action of contract, tort or otherwise, arising
     from, out of or in connection with the software or the use or other dealings
     in the Software.

   )* }}} *)

open Std
open Query_protocol

let dump (type a) : a t -> json =
  let mk command args = `Assoc (("command", `String command) :: args) in
  let mk_position = function
    | `Start -> `String "start"
    | `End -> `String "end"
    | `Offset n -> `Assoc [ ("offset", `Int n) ]
    | `Logical (line, col) ->
      `Assoc [ ("line", `Int line); ("column", `Int col) ]
  in
  let kinds_to_json kind =
    `List
      (List.map
         ~f:(function
           | `Constructor -> `String "constructor"
           | `Keywords -> `String "keywords"
           | `Labels -> `String "label"
           | `Modules -> `String "module"
           | `Modules_type -> `String "module-type"
           | `Types -> `String "type"
           | `Values -> `String "value"
           | `Variants -> `String "variant")
         kind)
  in
  function
  | Type_expr (expr, pos) ->
    mk "type-expression"
      [ ("expression", `String expr); ("position", mk_position pos) ]
  | Type_enclosing (opt_cursor, pos, index) ->
    mk "type-enclosing"
      [ ( "cursor",
          match opt_cursor with
          | None -> `Null
          | Some (text, offset) ->
            `Assoc [ ("text", `String text); ("offset", `Int offset) ] );
        ( "index",
          match index with
          | None -> `String "all"
          | Some n -> `Int n );
        ("position", mk_position pos)
      ]
  | Locate_type pos -> mk "locate-type" [ ("position", mk_position pos) ]
  | Locate_types pos -> mk "locate-types" [ ("position", mk_position pos) ]
  | Enclosing (start, stop) ->
    mk "enclosing"
      [ ("position", mk_position start);
        ( "end-position",
          match stop with
          | None -> `Null
          | Some stop -> mk_position stop )
      ]
  | Complete_prefix (prefix, pos, kind, doc, typ) ->
    mk "complete-prefix"
      [ ("prefix", `String prefix);
        ("position", mk_position pos);
        ("with-doc", `Bool doc);
        ("with-types", `Bool typ);
        ("kind", kinds_to_json kind)
      ]
  | Expand_prefix (prefix, pos, kind, typ) ->
    mk "expand-prefix"
      [ ("prefix", `String prefix);
        ("position", mk_position pos);
        ("with-types", `Bool typ);
        ("kind", kinds_to_json kind)
      ]
  | Document (identifier, pos) ->
    mk "document"
      [ ( "identifier",
          match identifier with
          | None -> `Null
          | Some ident -> `String ident );
        ("position", mk_position pos)
      ]
  | Syntax_document pos ->
    mk "syntax-document" [ ("position", mk_position pos) ]
  | Expand_ppx pos -> mk "ppx-expand" [ ("position", mk_position pos) ]
  | Locate (prefix, look_for, pos) ->
    mk "locate"
      [ ( "prefix",
          match prefix with
          | None -> `Null
          | Some prefix -> `String prefix );
        ( "look-for",
          match look_for with
          | `ML -> `String "implementation"
          | `MLI -> `String "interface" );
        ("position", mk_position pos)
      ]
  | Jump (target, pos) ->
    mk "jump" [ ("target", `String target); ("position", mk_position pos) ]
  | Phrase (target, pos) ->
    mk "phrase"
      [ ( "target",
          `String
            (match target with
            | `Next -> "next"
            | `Prev -> "prev") );
        ("position", mk_position pos)
      ]
  | Case_analysis (pos_start, pos_end) ->
    mk "case-analysis"
      [ ("start", mk_position pos_start); ("end", mk_position pos_end) ]
  | Holes -> mk "holes" []
  | Construct (pos, with_values, depth) ->
    let depth = Option.value ~default:1 depth in
    mk "construct"
      [ ("position", mk_position pos);
        ( "with_values",
          match with_values with
          | Some `None | None -> `String "none"
          | Some `Local -> `String "local" );
        ("depth", `Int depth)
      ]
  | Inlay_hints
      ( start,
        stop,
        hint_let_binding,
        hint_pattern_var,
        hint_function_params,
        ghost ) ->
    mk "inlay-hints"
      [ ("start", mk_position start);
        ("stop", mk_position stop);
        ("hint-let-binding", `Bool hint_let_binding);
        ("hint-pattern-variable", `Bool hint_pattern_var);
        ("hint-function-params", `Bool hint_function_params);
        ("avoid-ghost-location", `Bool ghost)
      ]
  | Outline -> mk "outline" []
  | Errors { lexing; parsing; typing } ->
    let args =
      if lexing && parsing && typing then []
      else
        [ ("lexing", `Bool lexing);
          ("parsing", `Bool parsing);
          ("typing", `Bool typing)
        ]
    in
    mk "errors" args
  | Shape pos -> mk "shape" [ ("position", mk_position pos) ]
  | Dump args -> mk "dump" [ ("args", `List args) ]
  | Path_of_source paths ->
    mk "path-of-source" [ ("paths", `List (List.map ~f:Json.string paths)) ]
  | List_modules exts ->
    mk "list-modules" [ ("extensions", `List (List.map ~f:Json.string exts)) ]
  | Findlib_list -> mk "findlib-list" []
  | Extension_list status ->
    mk "extension-list"
      [ ( "filter",
          match status with
          | `All -> `String "all"
          | `Enabled -> `String "enabled"
          | `Disabled -> `String "disabled" )
      ]
  | Path_list var ->
    mk "path-list"
      [ ( "variable",
          match var with
          | `Build -> `String "build"
          | `Source -> `String "source" )
      ]
  | Polarity_search (query, pos) ->
    mk "polarity-search"
      [ ("query", `String query); ("position", mk_position pos) ]
  | Type_search (query, pos, limit, with_doc) ->
    mk "type-search"
      [ ("query", `String query);
        ("position", mk_position pos);
        ("limit", `Int limit);
        ("with-doc", `Bool with_doc)
      ]
  | Occurrences (`Ident_at pos, scope) ->
    mk "occurrences"
      [ ("kind", `String "identifiers");
        ("position", mk_position pos);
        ( "scope",
          match scope with
          | `Buffer -> `String "local"
          | `Project -> `String "project"
          | `Renaming -> `String "renaming" )
      ]
  | Refactor_open (action, pos) ->
    mk "refactor-open"
      [ ( "action",
          `String
            (match action with
            | `Qualify -> "qualify"
            | `Unqualify -> "unqualify") );
        ("position", mk_position pos)
      ]
  | Refactor_extract_region (start, stop, _) ->
    mk "refactoring-extract-region"
      [ ("start", mk_position start); ("stop", mk_position stop) ]
  | Signature_help { position; _ } ->
    mk "signature-help" [ ("position", mk_position position) ]
  | Version -> mk "version" []

let string_of_completion_kind = function
  | `Value -> "Value"
  | `Variant -> "Variant"
  | `Constructor -> "Constructor"
  | `Label -> "Label"
  | `Module -> "Module"
  | `Modtype -> "Signature"
  | `Type -> "Type"
  | `Method -> "Method"
  | `MethodCall -> "#"
  | `Exn -> "Exn"
  | `Class -> "Class"
  | `ClassType -> "ClassType"
  | `Keyword -> "Keyword"

let with_location ?(with_file = false) ?(skip_none = false) loc assoc =
  let with_file l =
    if not with_file then l
    else ("file", `String loc.Location.loc_start.pos_fname) :: l
  in
  if skip_none && loc = Location.none then `Assoc assoc
  else
    `Assoc
      (with_file
      @@ ("start", Lexing.json_of_position loc.Location.loc_start)
         :: ("end", Lexing.json_of_position loc.Location.loc_end)
         :: assoc)

let json_of_type_loc (loc, desc, tail) =
  with_location loc
    [ ( "type",
        match desc with
        | `String _ as str -> str
        | `Index n -> `Int n );
      ( "tail",
        `String
          (match tail with
          | `No -> "no"
          | `Tail_position -> "position"
          | `Tail_call -> "call") )
    ]

let json_of_error (error : Location.error) =
  let of_sub loc sub =
    let msg =
      Location.print_sub_msg Format.str_formatter sub;
      String.trim (Format.flush_str_formatter ())
    in
    with_location ~skip_none:true loc [ ("message", `String msg) ]
  in
  let loc = Location.loc_of_report error in
  let msg = Format.asprintf "@[%a@]" Location.print_main error |> String.trim in
  let typ =
    match error.source with
    | Location.Lexer -> "lexer"
    | Location.Parser -> "parser"
    | Location.Typer -> "typer"
    | Location.Warning ->
      if String.is_prefixed ~by:"Error" msg then "typer"
        (* Handle warn-error (since 4.08) *)
      else "warning"
    | Location.Unknown -> "unknown"
    | Location.Env -> "env"
    | Location.Config -> "config"
  in
  let content =
    [ ("type", `String typ);
      ("sub", `List (List.map ~f:(of_sub loc) error.sub));
      ("valid", `Bool true);
      ("message", `String msg)
    ]
  in
  with_location ~skip_none:true loc content

let json_of_completion { Compl.name; kind; desc; info; deprecated } =
  `Assoc
    [ ("name", `String name);
      ("kind", `String (string_of_completion_kind kind));
      ("desc", `String desc);
      ("info", `String info);
      ("deprecated", `Bool deprecated)
    ]

let json_of_completions { Compl.entries; context } =
  `Assoc
    [ ("entries", `List (List.map ~f:json_of_completion entries));
      ( "context",
        match context with
        | `Unknown -> `Null
        | `Application { Compl.argument_type; labels } ->
          let label (name, ty) =
            `Assoc [ ("name", `String name); ("type", `String ty) ]
          in
          let a =
            `Assoc
              [ ("argument_type", `String argument_type);
                ("labels", `List (List.map ~f:label labels))
              ]
          in
          `List [ `String "application"; a ] )
    ]

let rec json_of_outline outline =
  let json_of_item
      { outline_name;
        outline_kind;
        outline_type;
        location;
        selection;
        children;
        deprecated
      } =
    with_location location
      [ ("name", `String outline_name);
        ("kind", `String (string_of_completion_kind outline_kind));
        ( "type",
          match outline_type with
          | None -> `Null
          | Some typ -> `String typ );
        ("children", `List (json_of_outline children));
        ("deprecated", `Bool deprecated);
        ("selection", with_location selection [])
      ]
  in
  List.map ~f:json_of_item outline

let rec json_of_shape { shape_loc; shape_sub } =
  with_location shape_loc
    [ ("children", `List (List.map ~f:json_of_shape shape_sub)) ]

let json_of_locate resp =
  match resp with
  | `At_origin -> `String "Already at definition point"
  | `Builtin s ->
    `String
      (sprintf
         "%S is a builtin, and it is therefore impossible to jump to its \
          definition"
         s)
  | `Invalid_context -> `String "Not a valid identifier"
  | `Not_found (id, None) -> `String ("didn't manage to find " ^ id)
  | `Not_found (i, Some f) ->
    `String (sprintf "%s was supposed to be in %s but could not be found" i f)
  | `Not_in_env str -> `String (Printf.sprintf "Not in environment '%s'" str)
  | `File_not_found msg -> `String msg
  | `Found (None, pos) -> `Assoc [ ("pos", Lexing.json_of_position pos) ]
  | `Found (Some file, pos) ->
    `Assoc [ ("file", `String file); ("pos", Lexing.json_of_position pos) ]

let json_of_locate_types (resp : Locate_types_result.t) =
  (* This function serializes to json differently than json_of_locate to make it easier
     to deserialize. *)
  let json_of_position
      ({ pos_fname; pos_lnum; pos_bol; pos_cnum } : Lexing.position) =
    `Assoc
      [ ("pos_fname", `String pos_fname);
        ("pos_lnum", `Int pos_lnum);
        ("pos_bol", `Int pos_bol);
        ("pos_cnum", `Int pos_cnum)
      ]
  in
  let json_of_option opt ~f =
    match opt with
    | None -> `Null
    | Some x -> f x
  in
  let json_of_locate_result result =
    let variant_name, payload =
      match result with
      | `Found (file, pos) ->
        let file = json_of_option file ~f:(fun file -> `String file) in
        ("Found", [ file; json_of_position pos ])
      | `File_not_found msg -> ("File_not_found", [ `String msg ])
      | `Builtin id -> ("Builtin", [ `String id ])
      | `Not_found (id, file) ->
        let file = json_of_option file ~f:(fun file -> `String file) in
        ("Not_found", [ `String id; file ])
      | `Not_in_env id -> ("Not_in_env", [ `String id ])
    in
    `List (`String variant_name :: payload)
  in
  let json_of_node_data : Locate_types_result.Tree.node_data -> _ = function
    | Arrow -> `List [ `String "Arrow" ]
    | Tuple -> `List [ `String "Tuple" ]
    | Object -> `List [ `String "Object" ]
    | Poly_variant -> `List [ `String "Poly_variant" ]
    | Type_ref { type_; result } ->
      `List
        [ `String "Type_ref";
          `Assoc
            [ ("type", `String type_);
              ("result", json_of_locate_result result)
            ]
        ]
    | Other type_ -> `List [ `String "Other"; `String type_ ]
  in
  let rec json_of_type_tree { Locate_types_result.Tree.data; children } =
    `Assoc
      [ ("data", json_of_node_data data);
        ("children", `List (List.map ~f:json_of_type_tree children))
      ]
  in
  match resp with
  | Success tree -> json_of_type_tree tree
  | Invalid_context -> `String "Invalid context"

let json_of_inlay_hints hints =
  let json_of_hint (position, label) =
    `Assoc
      [ ("pos", Lexing.json_of_position position); ("label", `String label) ]
  in
  `List (List.map ~f:json_of_hint hints)

let json_of_signature_help resp =
  let param { label_start; label_end } =
    `Assoc [ ("label", `List [ `Int label_start; `Int label_end ]) ]
  in
  match resp with
  | None -> `Assoc []
  | Some { label; parameters; active_param; active_signature } ->
    let signature =
      `Assoc
        [ ("label", `String label);
          ("parameters", `List (List.map ~f:param parameters))
        ]
    in
    `Assoc
      [ ("signatures", `List [ signature ]);
        ("activeParameter", `Int active_param);
        ("activeSignature", `Int active_signature)
      ]

let json_of_search_result list =
  let list =
    List.map
      ~f:(fun { name; typ; loc; cost; doc; constructible } ->
        with_location ~with_file:true loc
          [ ("name", `String name);
            ("type", `String typ);
            ("cost", `Int cost);
            ( "doc",
              match doc with
              | Some x -> `String x
              | None -> `Null );
            ("constructible", `String constructible)
          ])
      list
  in
  `List list

let json_of_substitution_result { loc; content; selection_range } =
  with_location loc
    [ ("content", `String content);
      ( "selection-range",
        `Assoc
          [ ("start", Lexing.json_of_position selection_range.Location.loc_start);
            ("end", Lexing.json_of_position selection_range.loc_end)
          ] )
    ]

let json_of_response (type a) (query : a t) (response : a) : json =
  match (query, response) with
  | Type_expr _, str -> `String str
  | Type_enclosing _, results -> `List (List.map ~f:json_of_type_loc results)
  | Enclosing _, results ->
    `List (List.map ~f:(fun loc -> with_location loc []) results)
  | Complete_prefix _, compl -> json_of_completions compl
  | Expand_prefix _, compl -> json_of_completions compl
  | Polarity_search _, compl -> json_of_completions compl
  | Type_search _, result -> json_of_search_result result
  | Refactor_open _, locations ->
    `List
      (List.map locations ~f:(fun (name, loc) ->
           with_location loc [ ("content", `String name) ]))
  | Refactor_extract_region _, subst_res ->
    json_of_substitution_result subst_res
  | Document _, resp ->
    begin match resp with
    | `No_documentation -> `String "No documentation available"
    | `Invalid_context -> `String "Not a valid identifier"
    | `Builtin s ->
      `String (sprintf "%S is a builtin, no documentation is available" s)
    | `Not_found (id, None) -> `String ("didn't manage to find " ^ id)
    | `Not_found (i, Some f) ->
      `String (sprintf "%s was supposed to be in %s but could not be found" i f)
    | `Not_in_env str -> `String (Printf.sprintf "Not in environment '%s'" str)
    | `File_not_found msg -> `String msg
    | `Found doc -> `String doc
    end
  | Syntax_document _, resp -> (
    match resp with
    | `Found info ->
      `Assoc
        [ ("name", `String info.name);
          ("description", `String info.description);
          ("url", `String info.documentation)
        ]
    | `No_documentation -> `String "No documentation found")
  | Expand_ppx _, resp ->
    let str =
      match resp with
      | `Found ppx_info ->
        `Assoc
          [ ("code", `String ppx_info.code);
            ( "deriver",
              `Assoc
                [ ("start", Lexing.json_of_position ppx_info.attr_start);
                  ("end", Lexing.json_of_position ppx_info.attr_end)
                ] )
          ]
      | `No_ppx ->
        `String "No PPX deriver/extension node found on this position"
    in
    str
  | Locate_type _, resp -> json_of_locate resp
  | Locate_types _, resp -> json_of_locate_types resp
  | Locate _, resp -> json_of_locate resp
  | Jump _, resp ->
    begin match resp with
    | `Error str -> `String str
    | `Found pos -> `Assoc [ ("pos", Lexing.json_of_position pos) ]
    end
  | Phrase _, pos -> `Assoc [ ("pos", Lexing.json_of_position pos) ]
  | Case_analysis _, ({ Location.loc_start; loc_end; _ }, str) ->
    let assoc =
      `Assoc
        [ ("start", Lexing.json_of_position loc_start);
          ("end", Lexing.json_of_position loc_end)
        ]
    in
    `List [ assoc; `String str ]
  | Holes, locations ->
    `List
      (List.map locations ~f:(fun (loc, typ) ->
           with_location loc [ ("type", `String typ) ]))
  | Construct _, ({ Location.loc_start; loc_end; _ }, strs) ->
    let assoc =
      `Assoc
        [ ("start", Lexing.json_of_position loc_start);
          ("end", Lexing.json_of_position loc_end)
        ]
    in
    `List [ assoc; `List (List.map ~f:Json.string strs) ]
  | Outline, outlines -> `List (json_of_outline outlines)
  | Shape _, shapes -> `List (List.map ~f:json_of_shape shapes)
  | Inlay_hints _, result -> json_of_inlay_hints result
  | Errors _, errors -> `List (List.map ~f:json_of_error errors)
  | Dump _, json -> json
  | Path_of_source _, str -> `String str
  | List_modules _, strs -> `List (List.map ~f:Json.string strs)
  | Findlib_list, strs -> `List (List.map ~f:Json.string strs)
  | Extension_list _, strs -> `List (List.map ~f:Json.string strs)
  | Path_list _, strs -> `List (List.map ~f:Json.string strs)
  | Occurrences (_, scope), (occurrences, _project) ->
    let with_file = scope = `Project || scope = `Renaming in
    `List
      (List.map occurrences ~f:(fun (occurrence : Query_protocol.occurrence) ->
           with_location ~with_file occurrence.loc
             [ ("stale", Json.bool occurrence.is_stale) ]))
  | Signature_help _, s -> json_of_signature_help s
  | Version, version -> `String version
