#!/usr/bin/env bash

source $[dirname $0]/reader.sh
source $[dirname $0]/printer.sh

# read
proc READ {
    test $(1) && setglobal r = $(1) || READLINE
    READ_STR $(r)
}

# eval
proc EVAL_AST {
    var ast = $(1), env = $(2)
    #_pr_str "${ast}"; echo "EVAL_AST '${ast}:${r} / ${env}'"
    _obj_type $(ast); var ot = $(r)
    match $(ot) {
    with symbol
        var val = $(ANON["${ast}"])
        eval r="\${$(env)["$(val)"]}"
        test $(r) || _error "'$(val)' not found" 
    with list
        _map_with_type _list EVAL $(ast) $(env) 
    with vector
        _map_with_type _vector EVAL $(ast) $(env) 
    with hash_map
        var res = '',"" key = '', val = '',"" hm = $(ANON["${ast}"])
        _hash_map; var new_hm = $(r)
        eval local keys="\${!$(hm)[@]}"
        for key in [$(keys)] {
            eval val="\${$(hm)[\"$(key)\"]}"
            EVAL $(val) $(env)
            _assoc! $(new_hm) $(key) $(r)
        }
        setglobal r = $(new_hm) 
    with *
        setglobal r = $(ast) 
    }
}

proc EVAL {
    var ast = $(1), env = $(2)
    setglobal r = ''
    [[ "${__ERROR}" ]] && return 1
    #_pr_str "${ast}"; echo "EVAL '${r} / ${env}'"
    _obj_type $(ast); var ot = $(r)
    if [[ "${ot}" != "list" ]] {
        EVAL_AST $(ast) $(env)
        return
    }
    _empty? $(ast) && setglobal r = $(ast) && return

    # apply list
    EVAL_AST $(ast) $(env)
    [[ "${__ERROR}" ]] && return 1
    var el = $(r)
    _first $(el); var f = $(r)
    _rest $(el); var args = $(ANON["${r}"])
    #echo "invoke: ${f} ${args}"
    eval $(f) $(args)
}

# print
proc PRINT {
    if [[ "${__ERROR}" ]] {
        _pr_str $(__ERROR) yes
        setglobal r = ""Error: $(r)""
        setglobal __ERROR = ''
    } else {
        _pr_str $(1) yes
    }TODO 
}

# repl
declare -A REPL_ENV = ''
proc REP {
    setglobal r = ''
    READ $(1)
    EVAL $(r) REPL_ENV
    PRINT $(r)
}

proc plus { setglobal r = $shExpr(' ${ANON["${1}"]} + ${ANON["${2}"]} '); _number $(r); }
proc minus { setglobal r = $shExpr(' ${ANON["${1}"]} - ${ANON["${2}"]} '); _number $(r); }
proc multiply { setglobal r = $shExpr(' ${ANON["${1}"]} * ${ANON["${2}"]} '); _number $(r); }
proc divide { setglobal r = $shExpr(' ${ANON["${1}"]} / ${ANON["${2}"]} '); _number $(r); }

setglobal REPL_ENV["+"]=plus
setglobal REPL_ENV["-"]=minus
setglobal REPL_ENV["__STAR__"]=multiply
setglobal REPL_ENV["/"]=divide

# repl loop
while true {
    READLINE "user> " || exit "$?"
    [[ "${r}" ]] && REP $(r) && echo $(r)
}