open Printf

open MatitaTypes


(** create a ProofEngineTypes.mk_fresh_name_type function which uses given
  * names as long as they are available, then it fallbacks to name generation
  * using FreshNamesGenerator module *)
let namer_of names =
  let len = List.length names in
  let count = ref 0 in
  fun metasenv context name ~typ ->
    if !count < len then begin
      let name = Cic.Name (List.nth names !count) in
      incr count;
      name
    end else
      FreshNamesGenerator.mk_fresh_name ~subst:[] metasenv context name ~typ

let tactic_of_ast = function
  | TacticAst.Intros (_, _, names) ->
      (* TODO Zack implement intros length *)
      PrimitiveTactics.intros_tac ~mk_fresh_name_callback:(namer_of names) ()
  | TacticAst.Reflexivity _ -> Tactics.reflexivity
  | TacticAst.Assumption _ -> Tactics.assumption
  | TacticAst.Contradiction _ -> Tactics.contradiction
  | TacticAst.Exists _ -> Tactics.exists
  | TacticAst.Fourier _ -> Tactics.fourier
  | TacticAst.Goal (_, n) -> Tactics.set_goal n
  | TacticAst.Left _ -> Tactics.left
  | TacticAst.Right _ -> Tactics.right
  | TacticAst.Ring _ -> Tactics.ring
  | TacticAst.Split _ -> Tactics.split
  | TacticAst.Symmetry _ -> Tactics.symmetry
  | TacticAst.Transitivity (_, term) -> Tactics.transitivity term
  | TacticAst.Apply (_, term) -> Tactics.apply term
  | TacticAst.Absurd (_, term) -> Tactics.absurd term
  | TacticAst.Exact (_, term) -> Tactics.exact term
  | TacticAst.Cut (_, term) -> Tactics.cut term
  | TacticAst.Elim (_, term, _) ->
      (* TODO Zack implement "using" argument *)
      (* old: Tactics.elim_intros_simpl term *)
      Tactics.elim_intros term
  | TacticAst.ElimType (_, term) -> Tactics.elim_type term
  | TacticAst.Replace (_, what, with_what) -> Tactics.replace ~what ~with_what
  | TacticAst.Auto (_,num) -> 
      AutoTactic.auto_tac ~num ~dbd:(MatitaDb.instance ())
  | TacticAst.Change (_, what, with_what, _) -> Tactics.change ~what ~with_what
(*
  (* TODO Zack a lot more of tactics to be implemented here ... *)
  | TacticAst.Change_pattern of 'term pattern * 'term * 'ident option
  | TacticAst.Change of 'term * 'term * 'ident option
  | TacticAst.Decompose of 'ident * 'ident list
  | TacticAst.Discriminate of 'ident
  | TacticAst.Fold of reduction_kind * 'term
  | TacticAst.Injection of 'ident
  | TacticAst.LetIn of 'term * 'ident
  | TacticAst.Replace_pattern of 'term pattern * 'term
*)
  | TacticAst.Reduce (_,reduction_kind,opts) ->
      let terms, also_in_hypotheses = 
        match opts with
        | Some (l,`Goal) -> Some l, false
        | Some (l,`Everywhere) -> Some l, true
        | None -> None, false
      in
      (match reduction_kind with
      | `Reduce -> Tactics.reduce ~also_in_hypotheses ~terms
      | `Simpl -> Tactics.simpl ~also_in_hypotheses ~terms
      | `Whd -> Tactics.whd ~also_in_hypotheses ~terms) 
  | TacticAst.Rewrite (_,dir,t,ident) ->
      if dir = `Left then
        EqualityTactics.rewrite_tac ~term:t 
      else
        EqualityTactics.rewrite_back_tac ~term:t
  | _ -> assert false

let eval_tactical status tac =
  let apply_tactic tactic =
    let (proof, goals) =
      ProofEngineTypes.apply_tactic tactic (MatitaMisc.get_proof_status status)
    in
    let new_status =
      match goals with
      | [] -> 
          let (_,metasenv,_,_) = proof in
          (match metasenv with
          | [] -> Proof proof
          | (ng,_,_)::_ -> Incomplete_proof (proof,ng))
      | ng::_ -> Incomplete_proof (proof, ng)
    in
    { status with proof_status = new_status }
  in
  let rec tactical_of_ast = function
    | TacticAst.Tactic (loc, tactic) -> tactic_of_ast tactic
    | TacticAst.Fail loc -> Tacticals.fail
    | TacticAst.Do (loc, num, tactical) ->
        Tacticals.do_tactic num (tactical_of_ast tactical)
    | TacticAst.IdTac loc -> Tacticals.id_tac
    | TacticAst.Repeat (loc, tactical) ->
        Tacticals.repeat_tactic (tactical_of_ast tactical)
    | TacticAst.Seq (loc, tacticals) ->  (* tac1; tac2; ... *)
        Tacticals.seq (List.map tactical_of_ast tacticals)
    | TacticAst.Then (loc, tactical, tacticals) ->  (* tac; [ tac1 | ... ] *)
        Tacticals.thens (tactical_of_ast tactical)
          (List.map tactical_of_ast tacticals)
    | TacticAst.Tries (loc, tacticals) ->
        Tacticals.try_tactics
          (List.map (fun t -> "", tactical_of_ast t) tacticals)
    | TacticAst.Try (loc, tactical) ->
        Tacticals.try_tactic (tactical_of_ast tactical)
  in
  apply_tactic (tactical_of_ast tac)

let eval_command status cmd =
  match cmd with
  | TacticAst.Set (loc, name, value) -> set_option status name value
  | TacticAst.Qed loc ->
      let uri, metasenv, bo, ty = 
        match status.proof_status with
        | Proof (Some uri, metasenv, body, ty) ->
            uri, metasenv, body, ty
        | Proof (None, metasenv, body, ty) -> 
            command_error 
              ("Someone allows to start a thm without giving the "^
               "name/uri. This should be fixed!")
        | _-> command_error "You can't qed an uncomplete theorem"
      in
      let suri = UriManager.string_of_uri uri in
      if metasenv <> [] then 
        command_error "Proof not completed! metasenv is not empty!";
      let proved_ty,ugraph = 
        CicTypeChecker.type_of_aux' [] [] bo CicUniv.empty_ugraph
      in
      let b,ugraph = 
        CicReduction.are_convertible [] proved_ty ty ugraph 
      in
      if not b then 
        command_error 
          ("The type of your proof is not convertible with the "^
          "type you've declared!");
      MatitaLog.message (sprintf "%s defined" suri);
      let status = MatitaSync.add_constant ~uri ~body:bo ~ty ~ugraph status in
      {status with proof_status = No_proof }
  | TacticAst.Inductive (loc, dummy_params, types) ->
      (* dummy_params are not real params, it is a list of nothing, and the only
       * semantic content is the len, that is leftno (note: leftno and pamaters
       * have nothing in common).
       *)
      let suri =
        match types with
        | (name, _, _, _) :: tl -> MatitaMisc.qualify status name ^ ".ind"
        | _ -> assert false
      in
      let uri = UriManager.uri_of_string suri in
      let leftno = List.length dummy_params in
      let obj = Cic.InductiveDefinition (types, [], leftno, []) in
      let ugraph =
        CicTypeChecker.typecheck_mutual_inductive_defs uri
          (types, [], leftno) CicUniv.empty_ugraph
      in
      let status = 
        MatitaSync.add_inductive_def
          ~uri ~types ~params:[] ~leftno ~ugraph status
      in
	{status with proof_status = No_proof }
  | TacticAst.Theorem (loc, thm_flavour, Some name, ty, None) ->
      let uri = 
        UriManager.uri_of_string (MatitaMisc.qualify status name ^ ".con") 
      in
      let goalno = 1 in
      let metasenv, body = 
        match status.proof_status with
        | Intermediate metasenv -> 
            ((goalno, [], ty) :: metasenv) , Cic.Meta (goalno,[])
        | _-> assert false
      in
      let initial_proof = (Some uri, metasenv, body, ty) in
      { status with proof_status = Incomplete_proof (initial_proof,goalno)}
  | TacticAst.Theorem (loc, thm_flavour, Some name, ty, Some body) ->
      let uri = 
        UriManager.uri_of_string (MatitaMisc.qualify status name ^ ".con") 
      in
      let metasenv = MatitaMisc.get_proof_metasenv status in
      let (body_type, ugraph) =
        CicTypeChecker.type_of_aux' metasenv [] body CicUniv.empty_ugraph
      in
      let (subst, metasenv, ugraph) =
        CicUnification.fo_unif metasenv [] body_type ty ugraph
      in
      if metasenv <> [] then
        command_error
          "metasenv not empty while giving a definition with body";
      let body = CicMetaSubst.apply_subst subst body in
      let ty = CicMetaSubst.apply_subst subst ty in
      let status = MatitaSync.add_constant ~uri ~body ~ty ~ugraph status in
      {status with proof_status = No_proof}
  | TacticAst.Theorem (_, _, None, _, _) ->
      command_error "The grammas should avoid having unnamed theorems!"
  | TacticAst.Coercion (loc, term) -> assert false  (** TODO *)
  | TacticAst.Alias (loc, spec) -> 
      match spec with
      | TacticAst.Ident_alias (id,uri) -> 
          {status with aliases = 
            DisambiguateTypes.Environment.add 
              (DisambiguateTypes.Id id) 
              ("boh?",(fun _ _ _ -> CicUtil.term_of_uri uri)) 
              status.aliases }
      | TacticAst.Symbol_alias (symb, instance, desc) ->
          {status with aliases = 
            DisambiguateTypes.Environment.add 
              (DisambiguateTypes.Symbol (symb,instance))
              (DisambiguateChoices.lookup_symbol_by_dsc symb desc) 
              status.aliases }
      | TacticAst.Number_alias (instance,desc) ->
          {status with aliases = 
            DisambiguateTypes.Environment.add 
              (DisambiguateTypes.Num instance) 
              (DisambiguateChoices.lookup_num_by_dsc desc) status.aliases }

let eval_executable status ex =
  match ex with
  | TacticAst.Tactical (_, tac) -> eval_tactical status tac
  | TacticAst.Command (_, cmd) -> eval_command status cmd
  | TacticAst.Macro (_, mac) -> 
      command_error (sprintf "The macro %s can't be in a script" 
        (TacticAstPp.pp_macro_cic mac))

let eval_comment status c = status
            
let eval status st =
  match st with
  | TacticAst.Executable (_,ex) -> eval_executable status ex
  | TacticAst.Comment (_,c) -> eval_comment status c

let disambiguate_term status term =
  let (aliases, metasenv, cic, _) =
    match
      MatitaDisambiguator.disambiguate_term ~dbd:(MatitaDb.instance ())
        ~aliases:(status.aliases) ~context:(MatitaMisc.get_proof_context status)
        ~metasenv:(MatitaMisc.get_proof_metasenv status) term
    with
    | [x] -> x
    | _ -> assert false
  in
  let proof_status =
    match status.proof_status with
    | No_proof -> Intermediate metasenv
    | Incomplete_proof ((uri, _, proof, ty), goal) ->
        Incomplete_proof ((uri, metasenv, proof, ty), goal)
    | Intermediate _ -> Intermediate metasenv 
    | Proof _ -> assert false
  in
  let status =
    { status with
        aliases = aliases;
        proof_status = proof_status }
  in
  status, cic
  
let disambiguate_terms status terms =
  let term = CicAst.pack terms in
  let status, term = disambiguate_term status term in
  status, CicUtil.unpack term
  
let disambiguate_tactic status = function
  | TacticAst.Transitivity (loc, term) -> 
      let status, cic = disambiguate_term status term in
      status, TacticAst.Transitivity (loc, cic)
  | TacticAst.Apply (loc, term) ->
      let status, cic = disambiguate_term status term in
      status, TacticAst.Apply (loc, cic)
  | TacticAst.Absurd (loc, term) -> 
      let status, cic = disambiguate_term status term in
      status, TacticAst.Absurd (loc, cic)
  | TacticAst.Exact (loc, term) -> 
      let status, cic = disambiguate_term status term in
      status, TacticAst.Exact (loc, cic)
  | TacticAst.Cut (loc, term) -> 
      let status, cic = disambiguate_term status term in
      status, TacticAst.Cut (loc, cic)
  | TacticAst.Elim (loc, term, Some term') ->
      let status, cic1 = disambiguate_term status term in
      let status, cic2 = disambiguate_term status term' in
      status, TacticAst.Elim (loc, cic1, Some cic2)
  | TacticAst.Elim (loc, term, None) ->
      let status, cic = disambiguate_term status term in
      status, TacticAst.Elim (loc, cic, None)
  | TacticAst.ElimType (loc, term) -> 
      let status, cic = disambiguate_term status term in
      status, TacticAst.ElimType (loc, cic)
  | TacticAst.Replace (loc, what, with_what) -> 
      let status, cic1 = disambiguate_term status what in
      let status, cic2 = disambiguate_term status with_what in
      status, TacticAst.Replace (loc, cic1, cic2)
  | TacticAst.Change (loc, what, with_what, ident) -> 
      let status, cic1 = disambiguate_term status what in
      let status, cic2 = disambiguate_term status with_what in
      status, TacticAst.Change (loc, cic1, cic2, ident)
(*
  (* TODO Zack a lot more of tactics to be implemented here ... *)
  | TacticAst.Change_pattern of 'term pattern * 'term * 'ident option
  | TacticAst.Change of 'term * 'term * 'ident option
  | TacticAst.Decompose of 'ident * 'ident list
  | TacticAst.Discriminate of 'ident
  | TacticAst.Fold of reduction_kind * 'term
  | TacticAst.Injection of 'ident
  | TacticAst.LetIn of 'term * 'ident
  | TacticAst.Replace_pattern of 'term pattern * 'term
*)
  | TacticAst.Reduce (loc, reduction_kind, opts) ->
      let status, opts = 
        match opts with
        | None -> status, None
        | Some (l,pat) -> 
            let status, l = 
              List.fold_right (fun t (status,acc) ->
                let status',t' = disambiguate_term status t in
                status', t'::acc) 
              l (status,[]) 
            in
            status, Some (l, pat)
      in
      status, TacticAst.Reduce (loc, reduction_kind, opts)
  | TacticAst.Rewrite (loc,dir,t,ident) ->
      let status, term = disambiguate_term status t in
      status, TacticAst.Rewrite (loc,dir,term,ident)
  | TacticAst.Intros (loc, num, names) ->
      status, TacticAst.Intros (loc, num, names)
  | TacticAst.Auto (loc,num) -> status, TacticAst.Auto (loc,num)
  | TacticAst.Reflexivity loc -> status, TacticAst.Reflexivity loc
  | TacticAst.Assumption loc -> status, TacticAst.Assumption loc
  | TacticAst.Contradiction loc -> status, TacticAst.Contradiction loc
  | TacticAst.Exists loc -> status, TacticAst.Exists loc 
  | TacticAst.Fourier loc -> status, TacticAst.Fourier loc
  | TacticAst.Left loc -> status, TacticAst.Left loc
  | TacticAst.Right loc -> status, TacticAst.Right loc
  | TacticAst.Ring loc -> status, TacticAst.Ring loc
  | TacticAst.Split loc -> status, TacticAst.Split loc
  | TacticAst.Symmetry loc -> status, TacticAst.Symmetry loc
  | TacticAst.Goal (loc, g) -> status, TacticAst.Goal (loc, g)
  | x -> 
      print_endline ("Not yet implemented:" ^ TacticAstPp.pp_tactic x);
      assert false

let rec disambiguate_tactical status = function 
  | TacticAst.Tactic (loc, tactic) -> 
      let status, tac = disambiguate_tactic status tactic in
      status, TacticAst.Tactic (loc, tac)
  | TacticAst.Do (loc, num, tactical) ->
      let status, tac = disambiguate_tactical status tactical in
      status, TacticAst.Do (loc, num, tac)
  | TacticAst.Repeat (loc, tactical) -> 
      let status, tac = disambiguate_tactical status tactical in
      status, TacticAst.Repeat (loc, tac)
  | TacticAst.Seq (loc, tacticals) ->  (* tac1; tac2; ... *)
      let status, tacticals = disambiguate_tacticals status tacticals in
      let tacticals = List.rev tacticals in
      status, TacticAst.Seq (loc, tacticals)
  | TacticAst.Then (loc, tactical, tacticals) ->  (* tac; [ tac1 | ... ] *)
      let status, tactical = disambiguate_tactical status tactical in
      let status, tacticals = disambiguate_tacticals status tacticals in
      status, TacticAst.Then (loc, tactical, tacticals)
  | TacticAst.Tries (loc, tacticals) ->
      let status, tacticals = disambiguate_tacticals status tacticals in
      status, TacticAst.Tries (loc, tacticals)
  | TacticAst.Try (loc, tactical) ->
      let status, tactical = disambiguate_tactical status tactical in
      status, TacticAst.Try (loc, tactical)
  | (TacticAst.IdTac _ | TacticAst.Fail _) as tac ->
      status, tac

and disambiguate_tacticals status tacticals =
  let status, tacticals =
    List.fold_left
      (fun (status, tacticals) tactical ->
        let status, tac = disambiguate_tactical status tactical in
        status, tac :: tacticals)
      (status, [])
      tacticals
  in
  let tacticals = List.rev tacticals in
  status, tacticals
  
let disambiguate_inddef status params indTypes =
  let add_pi binders t =
    List.fold_right
      (fun (name, ast) acc ->
        CicAst.Binder (`Forall, (Cic.Name name, Some ast), acc))
      binders t
  in
  let ind_binders =
    List.map (fun (name, _, typ, _) -> (name, add_pi params typ)) indTypes
  in
  let binders = ind_binders @ params in
  let asts = ref [] in
  let add_ast ast = asts := ast :: !asts in
  let paramsno = List.length params in
  let indbindersno = List.length ind_binders in
  List.iter
    (fun (name, _, typ, constructors) ->
      add_ast (add_pi params typ);
      List.iter (fun (_, ast) -> add_ast (add_pi binders ast)) constructors)
    indTypes;
  let status, terms = disambiguate_terms status !asts in
  let terms = ref (List.rev terms) in
  let get_term () =
    match !terms with [] -> assert false | hd :: tl -> terms := tl; hd
  in
  let uri =
    match indTypes with
    | (name, _, _, _) :: _ -> MatitaMisc.qualify status name ^ ".ind"
    | _ -> assert false
  in
  let mutinds =
    let counter = ref 0 in
    List.map
      (fun _ ->
        incr counter;
        CicUtil.term_of_uri (sprintf "%s#xpointer(1/%d)" uri !counter))
      indTypes
  in
  let subst_mutinds = List.fold_right CicSubstitution.subst mutinds in
  let cicIndTypes =
    List.fold_left
      (fun acc (name, inductive, typ, constructors) ->
        let cicTyp = get_term () in
        let cicConstructors =
          List.fold_left
            (fun acc (name, _) ->
              let typ =
                subst_mutinds (CicUtil.strip_prods indbindersno (get_term ()))
              in
              (name, typ) :: acc)
            [] constructors
        in
        (name, inductive, cicTyp, List.rev cicConstructors) :: acc)
      [] indTypes
  in
  let cicIndTypes = List.rev cicIndTypes in
  status, (UriManager.uri_of_string uri, (cicIndTypes, [], paramsno))

let disambiguate_command status = function
  | TacticAst.Inductive (loc, params, types) ->
      let (status, (uri, (ind_types, vars, paramsno))) =
        disambiguate_inddef status params types
      in
      let rec mk_list = function
        | 0 -> []
        | n -> ("", Cic.Rel ~-117) :: mk_list (n-1)
      in  
      (* once we've built the cic inductive types we no longer need terms
         corresponding to parameters, but we need the leftno, and we encode
         it as the length of dummy_params
      *)
      let dummy_params = mk_list paramsno in
      status, TacticAst.Inductive (loc, dummy_params, ind_types)
  | TacticAst.Theorem (loc, thm_flavour, name, ty, body) ->
      let status, ty = disambiguate_term status ty in
      let status, body =
        match body with
        | None -> status, None
        | Some body ->
            let status, body = disambiguate_term status body in
            status, Some body
      in
      status, TacticAst.Theorem (loc, thm_flavour, name, ty, body)
  | TacticAst.Coercion (loc, term) -> assert false  (** TODO *)
  | (TacticAst.Set _ | TacticAst.Qed _) as cmd ->
      status, cmd
  | TacticAst.Alias _ as x -> status, x

let disambiguate_executable status ex =
  match ex with
  | TacticAst.Tactical (loc, tac) ->
      let status, tac = disambiguate_tactical status tac in
      status, (TacticAst.Tactical (loc, tac))
  | TacticAst.Command (loc, cmd) ->
      let status, cmd = disambiguate_command status cmd in
      status, (TacticAst.Command (loc, cmd))
  | TacticAst.Macro (_, mac) -> 
      command_error 
        (sprintf ("The engine is not allowed to disambiguate any macro, "^^
                 "in particular %s") (TacticAstPp.pp_macro_ast mac))

let disambiguate_comment status c = 
  match c with
  | TacticAst.Note (loc,n) -> status, TacticAst.Note (loc,n)
  | TacticAst.Code (loc,ex) -> 
        let status, ex = disambiguate_executable status ex in
        status, TacticAst.Code (loc,ex)
        
let disambiguate_statement status statement =
  match statement with
  | TacticAst.Comment (loc,c) -> 
        let status, c = disambiguate_comment status c in
        status, TacticAst.Comment (loc,c)
  | TacticAst.Executable (loc,ex) -> 
        let status, ex = disambiguate_executable status ex in
        status, TacticAst.Executable (loc,ex)
  
let eval_ast status ast =
  let status,st = disambiguate_statement status ast in
  (* this disambiguation step should be deferred to support tacticals *)
  eval status st

let eval_from_stream status str =
  let st = CicTextualParser2.parse_statement str in
  eval_ast status st
  
let eval_string status str =
  eval_from_stream status (Stream.of_string str) 

let default_options () =
  let options =
    StringMap.add "baseuri"
      (String
        (Helm_registry.get "matita.baseuri" ^ Helm_registry.get "matita.owner"))
      no_options
  in
  let options =
    StringMap.add "basedir"
      (String (Helm_registry.get "matita.basedir" ))
      options
  in
  options

let initial_status =
  lazy {
    aliases = DisambiguateTypes.empty_environment;
    proof_status = No_proof;
    options = default_options ();
    coercions = [];
    objects = [];
  }