(***********************************************************************)
(*  v      *   The Coq Proof Assistant  /  The Coq Development Team    *)
(* <O___,, *        INRIA-Rocquencourt  &  LRI-CNRS-Orsay              *)
(*   \VV/  *************************************************************)
(*    //   *      This file is distributed under the terms of the      *)
(*         *       GNU Lesser General Public License Version 2.1       *)
(***********************************************************************)

(* $Id$ *)

open Pp
open Util
open Options
open Term
open Declarations
open Inductive
open Environ
open Reduction
open Tacred
open Declare
open Names
open Coqast
open Ast
open Library
open Libobject
open Astterm
open Proof_type
open Tacmach

let mkCastC(c,t) = ope("CAST",[c;t])
let mkLambdaC(x,a,b) = ope("LAMBDA",[a;slam(Some (string_of_id x),b)])
let mkLambdaCit = List.fold_right (fun (x,a) b -> mkLambdaC(x,a,b))
let mkProdC (x,a,b) = ope("PROD",[a;slam(Some (string_of_id x),b)])
let mkProdCit = List.fold_right (fun (x,a) b -> mkProdC(x,a,b))

(* Commands of the interface *)

(* 1| Constant definitions *)

let constant_entry_of_com (com,comtypopt) =
  let sigma = Evd.empty in
  let env = Global.env() in
  match comtypopt with
      None -> 
	{ const_entry_body = interp_constr sigma env com;
	  const_entry_type = None }
    | Some comtyp ->
	let typ = interp_type sigma env comtyp in
	{ const_entry_body = interp_casted_constr sigma env com typ;
	  const_entry_type = Some typ }

let red_constant_entry ce = function
  | None -> ce
  | Some red ->
      let body = ce.const_entry_body in
      { const_entry_body = 
	  reduction_of_redexp red (Global.env()) Evd.empty body; 
	const_entry_type = 
	  ce.const_entry_type }

let constr_of_constr_entry ce =
  match ce.const_entry_type with
    | None -> ce.const_entry_body 
    | Some t -> mkCast (ce.const_entry_body, t)

let declare_global_definition ident ce n local =
  let sp = declare_constant ident (ConstantEntry ce,n,false) in
  if local then
    wARNING [< pr_id ident; 'sTR" is declared as a global definition" >];
  if is_verbose() then
    message ((string_of_id ident) ^ " is defined");
  ConstRef sp

let definition_body_red red_option ident (local,n) com comtypeopt = 
  let ce = constant_entry_of_com (com,comtypeopt) in
  let ce' = red_constant_entry ce red_option in
  match n with
    | NeverDischarge -> declare_global_definition ident ce' n local
    | DischargeAt disch_sp ->
        if Lib.is_section_p disch_sp then begin
	  let c = constr_of_constr_entry ce' in
          let sp = declare_variable ident (SectionLocalDef c,n,false) in
	  if is_verbose() then message ((string_of_id ident) ^ " is defined");
          if Pfedit.refining () then 
            mSGERRNL [< 'sTR"Warning: Local definition "; pr_id ident; 
                        'sTR" is not visible from current goals" >];
	  VarRef sp
        end
	else
	  declare_global_definition ident ce' n true
    | NotDeclare ->
      anomalylabstrm "Command.definition_body_red"
        [<'sTR "Strength NotDeclare not for Definition, only for Let" >]

let definition_body = definition_body_red None

let syntax_definition ident com =
  let c = interp_rawconstr Evd.empty (Global.env()) com in 
  Syntax_def.declare_syntactic_definition ident c;
  if is_verbose() then 
    message ((string_of_id ident) ^ " is now a syntax macro")

(* 2| Variable definitions *)

let parameter_def_var ident c =
  let c = interp_type Evd.empty (Global.env()) c in
  let sp = declare_parameter (id_of_string ident) c in
  if is_verbose() then message (ident ^ " is assumed");
  sp

let declare_global_assumption ident c =
  let sp = parameter_def_var ident c in
  wARNING [< 'sTR ident; 'sTR" is declared as a parameter";
             'sTR" because it is at a global level" >];
  ConstRef sp

let hypothesis_def_var is_refining ident n c =
  match n with
    | NeverDischarge -> declare_global_assumption ident c
    | DischargeAt disch_sp ->
        if Lib.is_section_p disch_sp then begin
	  let t = interp_type Evd.empty (Global.env()) c in
          let sp = declare_variable (id_of_string ident)
		     (SectionLocalAssum t,n,false) in
	  if is_verbose() then message (ident ^ " is assumed");
          if is_refining then 
            mSGERRNL [< 'sTR"Warning: Variable "; 'sTR ident; 
                        'sTR" is not visible from current goals" >];
	  VarRef sp
        end
	else
	  declare_global_assumption ident c
    | NotDeclare ->
      anomalylabstrm "Command.hypothesis_def_var"
        [<'sTR "Strength NotDeclare not for Variable, only for Let" >]

(* 3| Mutual Inductive definitions *)

let minductive_message = function 
  | []  -> anomaly "no inductive definition"
  | [x] -> [< pr_id x; 'sTR " is defined">]
  | l   -> hOV 0  [< prlist_with_sep pr_coma pr_id l;
		     'sPC; 'sTR "are defined">]

let recursive_message = function 
  | []  -> anomaly "no recursive definition"
  | [sp] -> [< Printer.pr_global sp; 'sTR " is recursively defined">]
  | l   -> hOV 0 [< prlist_with_sep pr_coma Printer.pr_global l;
		    'sPC; 'sTR "are recursively defined">]

let corecursive_message = function 
  | []  -> anomaly "no corecursive definition"
  | [x] -> [< Printer.pr_global x; 'sTR " is corecursively defined">]
  | l   -> hOV 0 [< prlist_with_sep pr_coma Printer.pr_global l;
                    'sPC; 'sTR "are corecursively defined">]

let interp_mutual lparams lnamearconstrs finite = 
  let allnames = 
    List.fold_left 
      (fun acc (id,_,l) -> id::(List.map fst l)@acc) [] lnamearconstrs in
  if not (list_distinct allnames) then
    error "Two inductive objects have the same name";
  let nparams = List.length lparams
  and sigma = Evd.empty 
  and env0 = Global.env() in
  let env_params, params =
    List.fold_left
      (fun (env, params) (id,t) ->
	 let p = interp_type sigma env t in
	 (Environ.push_rel_assum (Name id,p) env, (Name id,p)::params))
      (env0,[]) lparams
  in
  (* Pour permettre à terme les let-in dans les params *)
  let params' =
    List.map (fun (na,p) ->
		let id = match na with
		  | Name id -> id
		  | Anonymous -> anomaly "Unnamed inductive variable"
		in (id, LocalAssum p)) params
  in
  let (ind_env,ind_impls,arityl) =
    List.fold_left
      (fun (env, ind_impls, arl) (recname, arityc,_) ->
         let arity = interp_type sigma env_params arityc in
	 let fullarity = prod_it arity params in
	 let env' = Environ.push_rel_assum (Name recname,fullarity) env in
	 let impls = 
	   if Impargs.is_implicit_args()
	   then Impargs.compute_implicits env_params sigma fullarity
	   else [] in
	 (env', (recname,impls)::ind_impls, (arity::arl)))
      (env0, [], []) lnamearconstrs
  in
  let ind_env_params = Environ.push_rels_assum params ind_env in
  let mispecvec = 
    List.map2
      (fun ar (name,_,lname_constr) ->
	 let constrnames, bodies = List.split lname_constr in
         let constrs =
	   List.map 
	     (interp_type_with_implicits sigma ind_env_params ind_impls) bodies
	 in
	 { mind_entry_nparams = nparams;
	   mind_entry_params = params';
	   mind_entry_typename = name;
	   mind_entry_arity = ar;
	   mind_entry_consnames = constrnames;
	   mind_entry_lc = constrs })
      (List.rev arityl) lnamearconstrs
  in
  { mind_entry_finite = finite; mind_entry_inds = mispecvec }

let declare_mutual_with_eliminations mie =
  let lrecnames =
    List.map (fun e -> e.mind_entry_typename) mie.mind_entry_inds in
  let sp = declare_mind mie in
  if is_verbose() then pPNL(minductive_message lrecnames);
  declare_eliminations sp;
  sp

let build_mutual lparams lnamearconstrs finite =
  let mie = interp_mutual lparams lnamearconstrs finite in
  let _ = declare_mutual_with_eliminations mie in ()

(* try to find non recursive definitions *)

let list_chop_hd i l = match list_chop i l with
  | (l1,x::l2) -> (l1,x,l2)
  | _ -> assert false

let collect_non_rec  = 
  let rec searchrec lnonrec lnamerec ldefrec larrec nrec = 
    try
      let i = 
        list_try_find_i
          (fun i f ->
             if List.for_all (fun def -> not (occur_var f def)) ldefrec
             then i else failwith "try_find_i")
          0 lnamerec 
      in
      let (lf1,f,lf2) = list_chop_hd i lnamerec in
      let (ldef1,def,ldef2) = list_chop_hd i ldefrec in
      let (lar1,ar,lar2) = list_chop_hd i larrec in
      let newlnv = 
	try 
	  match list_chop i nrec with 
            | (lnv1,_::lnv2) -> (lnv1@lnv2)
	    | _ -> [] (* nrec=[] for cofixpoints *)
        with Failure "list_chop" -> []
      in 
      searchrec ((f,mkCast (def,body_of_type ar))::lnonrec) 
        (lf1@lf2) (ldef1@ldef2) (lar1@lar2) newlnv
    with Failure "try_find_i" -> 
      (lnonrec, (lnamerec,ldefrec,larrec,nrec))
  in 
  searchrec [] 

let build_recursive lnameargsardef = 
  let lrecnames = List.map (fun (f,_,_,_) -> f) lnameargsardef
  and sigma = Evd.empty
  and env0 = Global.env()
  and nv = Array.of_list (List.map (fun (_,la,_,_) -> (List.length la) -1)
                            lnameargsardef) 
  in
  let fs = States.freeze() in
  let (rec_sign,arityl) = 
    try 
      List.fold_left 
        (fun (env,arl) (recname,lparams,arityc,_) -> 
           let raw_arity = mkProdCit lparams arityc in
           let arity = interp_type sigma env0 raw_arity in
           let _ = declare_variable recname
	     (SectionLocalAssum arity, NeverDischarge, false) in
           (Environ.push_named_assum (recname,arity) env, (arity::arl)))
        (env0,[]) lnameargsardef
    with e ->
      States.unfreeze fs; raise e
  in
  let arityl = List.rev arityl in
  let recdef =
    try 
      List.map2
	(fun (_,lparams,_,def) arity ->
           interp_casted_constr sigma rec_sign (mkLambdaCit lparams def) arity)
        lnameargsardef arityl
    with e ->
      States.unfreeze fs; raise e
  in
  States.unfreeze fs;
  let (lnonrec,(lnamerec,ldefrec,larrec,nvrec)) = 
    collect_non_rec lrecnames recdef arityl (Array.to_list nv) in
  let n = NeverDischarge in 
  if lnamerec <> [] then begin
    let recvec = 
      Array.map (subst_vars (List.rev lnamerec)) (Array.of_list ldefrec) in
    let varrec = Array.of_list larrec in
    let rec declare i = function 
      | fi::lf ->
	  let ce = 
	    { const_entry_body =
		mkFix ((Array.of_list nvrec,i),
		       (varrec,List.map (fun id -> Name id) lnamerec,
			recvec));
	      const_entry_type = None } 
	  in
	  let sp = declare_constant fi (ConstantEntry ce, n, false) in
          (ConstRef sp)::(declare (i+1) lf)
      | _ -> [] 
    in 
    (* declare the recursive definitions *)
    let lrefrec = declare 0 lnamerec in
    if is_verbose() then pPNL(recursive_message lrefrec)
  end;
  (* The others are declared as normal definitions *)
  let var_subst id = (id, global_reference CCI id) in
  let _ = 
    List.fold_left
      (fun subst (f,def) ->
	 let ce = { const_entry_body = replace_vars subst def;
		    const_entry_type = None } in
	 let _ = declare_constant f (ConstantEntry ce,n,false) in
      	 warning ((string_of_id f)^" is non-recursively defined");
      	 (var_subst f) :: subst)
      (List.map var_subst lnamerec)
      lnonrec 
  in
  ()

let build_corecursive lnameardef = 
  let lrecnames = List.map (fun (f,_,_) -> f) lnameardef
  and sigma = Evd.empty
  and env0 = Global.env() in
  let fs = States.freeze() in
  let (rec_sign,arityl) = 
    try 
      List.fold_left 
        (fun (env,arl) (recname,arityc,_) -> 
           let arj = type_judgment_of_rawconstr Evd.empty env0 arityc in
	   let arity = arj.utj_val in
           let _ = declare_variable recname
	     (SectionLocalAssum arj.utj_val,NeverDischarge,false) in
           (Environ.push_named_assum (recname,arity) env, (arity::arl)))
        (env0,[]) lnameardef
    with e -> 
      States.unfreeze fs; raise e
  in 
  let recdef =
    try 
      List.map (fun (_,arityc,def) -> 
                  interp_constr sigma rec_sign
                    (mkCastC(def,arityc)))
        lnameardef
    with e -> 
      States.unfreeze fs; raise e 
  in
  States.unfreeze fs;
  let (lnonrec,(lnamerec,ldefrec,larrec,_)) = 
    collect_non_rec lrecnames recdef (List.rev arityl) [] in
  let n = NeverDischarge in 
  if lnamerec <> [] then begin
    let recvec = 
      if lnamerec = [] then 
	[||] 
      else 
	Array.map (subst_vars (List.rev lnamerec)) (Array.of_list ldefrec) in
    let varrec = Array.of_list larrec in
    let rec declare i = function 
      | fi::lf ->
	  let ce = 
	    { const_entry_body =
		mkCoFix (i, (varrec,List.map (fun id -> Name id) lnamerec,
			     recvec));
	      const_entry_type = None } 
	  in
          let sp = declare_constant fi (ConstantEntry ce,n,false) in
          (ConstRef sp) :: declare (i+1) lf
      | _        -> [] 
    in 
    let lrefrec = declare 0 lnamerec in
    if is_verbose() then pPNL(corecursive_message lrefrec)
  end;
  let var_subst id = (id, global_reference CCI id) in
  let _ = 
    List.fold_left
      (fun subst (f,def) ->
	 let ce = { const_entry_body = replace_vars subst def;
		    const_entry_type = None } in
	 let _ = declare_constant f (ConstantEntry ce,n,false) in
      	 warning ((string_of_id f)^" is non-recursively defined");
      	 (var_subst f) :: subst)
      (List.map var_subst lnamerec)
      lnonrec 
  in
  ()

let inductive_of_ident id =
  let c =
    try global_reference CCI id
    with Not_found ->
      errorlabstrm "inductive_of_ident"
	[< 'sTR ((string_of_id id) ^ " not found") >]
  in
  match kind_of_term (global_reference CCI id) with
    | IsMutInd ind -> ind
    | _ -> errorlabstrm "inductive_of_ident"
	[< 'sTR (string_of_id id); 'sPC; 'sTR "is not an inductive type" >]

let build_scheme lnamedepindsort = 
  let lrecnames = List.map (fun (f,_,_,_) -> f) lnamedepindsort
  and sigma = Evd.empty
  and env0 = Global.env() in
  let lrecspec =
    List.map (fun (_,dep,indid,sort) -> 
                let s = destSort (interp_constr sigma env0 sort) in
                (inductive_of_ident indid,dep,s)) lnamedepindsort
  in
  let n = NeverDischarge in 
  let listdecl = Indrec.build_mutual_indrec env0 sigma lrecspec in 
  let rec declare decl fi lrecref =
    let ce = { const_entry_body = decl; const_entry_type = None } in
    let sp = declare_constant fi (ConstantEntry ce,n,false) in
    ConstRef sp :: lrecref
  in 
  let lrecref = List.fold_right2 declare listdecl lrecnames [] in
  if is_verbose() then pPNL(recursive_message lrecref)

let start_proof_com sopt stre com =
  let env = Global.env () in
  let sign = Global.named_context () in
  let id = match sopt with
    | Some id -> id
    | None ->
	next_ident_away (id_of_string "Unnamed_thm")
	  (Pfedit.get_all_proof_names ())
  in
  Pfedit.start_proof id stre sign (interp_type Evd.empty env com)

let apply_tac_not_declare id pft = function
  | None -> error "Type of Let missing"
  | Some typ ->
    let cutt = vernac_tactic ("Cut",[Constr typ])
    and exat = vernac_tactic ("Exact",[Constr pft]) in
    Pfedit.delete_current_proof ();
    Pfedit.by (tclTHENS cutt [introduction id;exat])

let save opacity id ({const_entry_body = pft; const_entry_type = tpo} as const)
  strength =
  begin match strength with
    | DischargeAt disch_sp when Lib.is_section_p disch_sp ->
	let c = constr_of_constr_entry const in
	let _ = declare_variable id (SectionLocalDef c,strength,opacity) in ()
    | NeverDischarge | DischargeAt _ ->
        let _ = declare_constant id (ConstantEntry const,strength,opacity)in ()
    | NotDeclare -> apply_tac_not_declare id pft tpo
  end;
  if not (strength = NotDeclare) then
  begin
    Pfedit.delete_current_proof ();
    if Options.is_verbose() then
      message ((string_of_id id) ^ " is defined")
  end

let save_named opacity =
  let id,(const,strength) = Pfedit.cook_proof () in
  save opacity id const strength

let save_anonymous_with_strength opacity save_ident id const strength =
  if atompart_of_id id <> "Unnamed_thm" then
    message("Overriding name "^(string_of_id id)^" and using "^save_ident);
  save opacity (id_of_string save_ident) const strength

let save_anonymous opacity save_ident =
  let id,(const,strength) = Pfedit.cook_proof () in
  save_anonymous_with_strength opacity save_ident id const strength

let save_anonymous_thm opacity save_ident =
  let id,(const,_) = Pfedit.cook_proof () in
  save_anonymous_with_strength opacity save_ident id const NeverDischarge

let save_anonymous_remark opacity save_ident =
  let id,(const,_) = Pfedit.cook_proof ()
  and path = try List.tl (List.tl (Lib.cwd())) with Failure _ -> [] in
  save_anonymous_with_strength opacity save_ident id const (make_strength path)

let get_current_context () =
  try Pfedit.get_current_goal_context ()
  with e when Logic.catchable_exception e -> 
    (Evd.empty, Global.env())