import critbits, strutils, os
import 
  ../core/types,
  ../core/parser, 
  ../core/interpreter, 
  ../core/utils,
  ../core/regex,
  ../vendor/routine

ROOT

  .symbol("exit") do (i: In):
    quit(0)

  .symbol("symbols") do (i: In):
    var q = newSeq[MinValue](0)
    var scope = i.scope
    while scope.isNotNil:
      for s in scope.symbols.keys:
        q.add s.newVal
      scope = scope.parent
    i.push q.newVal

  .symbol("sigils") do (i: In):
    var q = newSeq[MinValue](0)
    var scope = i.scope
    while scope.isNotNil:
      for s in scope.sigils.keys:
        q.add s.newVal
      scope = scope.parent
    i.push q.newVal

  .symbol("debug?") do (i: In):
    i.push i.debugging.newVal

  .symbol("debug") do (i: In):
    i.debugging = not i.debugging 
    echo "Debugging: $1" % [$i.debugging]

  # Language constructs

  .symbol("define") do (i: In):
    var q2 = i.pop # new (can be a quoted symbol or a string)
    var q1 = i.pop # existing (auto-quoted)
    var symbol: string
    if not q1.isQuotation:
      q1 = @[q1].newVal
    if q2.isString:
      symbol = q2.strVal
    elif q2.isQuotation and q2.qVal.len == 1 and q2.qVal[0].kind == minSymbol:
      symbol = q2.qVal[0].symVal
    else:
      raiseInvalid("The top quotation must contain only one symbol value")
    i.debug "[define] " & symbol & " = " & $q1
    i.scope.symbols[symbol] = proc(i: In) =
      i.push q1.qVal

  .symbol("bind") do (i: In):
    var q2 = i.pop # new (can be a quoted symbol or a string)
    var q1 = i.pop # existing (auto-quoted)
    var symbol: string
    if not q1.isQuotation:
      q1 = @[q1].newVal
    if q2.isStringLike:
      symbol = q2.getString
    elif q2.isQuotation and q2.qVal.len == 1 and q2.qVal[0].kind == minSymbol:
      symbol = q2.qVal[0].symVal
    else:
      raiseInvalid("The top quotation must contain only one symbol value")
    i.debug "[bind] " & symbol & " = " & $q1
    let res = i.scope.setSymbol(symbol) do (i: In):
      i.push q1.qVal
    if not res:
      raiseUndefined("Attempting to bind undefined symbol: " & symbol)

  .symbol("delete") do (i: In):
    var sym: MinValue 
    i.reqStringOrSymbol sym
    let res = i.scope.delSymbol(sym.getString) 
    if not res:
      raiseUndefined("Attempting to delete undefined symbol: " & sym.getString)

  .symbol("scope") do (i: In):
    var code: MinValue
    i.reqQuotation code
    code.filename = i.filename
    i.unquote("<scope>", code)
    i.push @[code].newVal

  .symbol("import") do (i: In):
    var mdl: MinValue
    var name: string
    name = i.pop.strVal
    i.scope.getSymbol(name)(i)
    mdl = i.pop
    if not mdl.isQuotation:
      raiseInvalid("No quotation was found on the stack")
    if mdl.scope.isNotNil:
      #echo "MODULE SCOPE PARENT: ", mdl.scope.name
      for sym, val in mdl.scope.symbols.pairs:
        i.debug "[import] $1:$2" % [i.scope.name, sym]
        i.scope.symbols[sym] = val
  
  .sigil("'") do (i: In):
    i.push(@[MinValue(kind: minSymbol, symVal: i.pop.strVal)].newVal)

  .symbol("sigil") do (i: In):
    var q1, q2: MinValue
    i.reqTwoQuotations q1, q2
    if q1.qVal.len == 1 and q1.qVal[0].kind == minSymbol:
      var symbol = q1.qVal[0].symVal
      if symbol.len == 1:
        if i.scope.getSigil(symbol).isNotNil:
          raiseInvalid("Sigil '$1' already exists" % [symbol])
        i.scope.sigils[symbol] = proc(i: In) =
          i.evaluating = true
          i.push q2.qVal
          i.evaluating = false
      else:
        raiseInvalid("A sigil can only have one character")
    else:
      raiseInvalid("The top quotation must contain only one symbol value")

  .symbol("eval") do (i: In):
    var s: MinValue
    i.reqString s
    i.eval s.strVal

  .symbol("load") do (i: In):
    var s: MinValue
    i.reqString s
    var file = s.strVal
    if not file.endsWith(".min"):
      file = file & ".min"
    i.load i.pwd.joinPath(file)

  .symbol("call") do (i: In):
    var symbols, target: MinValue
    i.reqTwoQuotations symbols, target
    let vals = symbols.qVal
    var q: MinValue
    if vals.len == 0:
      raiseInvalid("No symbol to call")
    let origScope = i.scope
    i.scope = target.scope
    for c in 0..vals.len-1:
      if not vals[c].isStringLike:
        raiseInvalid("Quotation must contain only symbols or strings")
      let symbol = vals[c].getString
      let qProc = i.scope.getSymbol(symbol)
      if qProc.isNil:
        raiseUndefined("Symbol '$1' not found in scope '$2'" % [symbol, i.scope.fullname])
      qProc(i)
      if vals.len > 1 and c < vals.len-1:
        q = i.pop
        if not q.isQuotation:
          raiseInvalid("Unable to evaluate symbol '$1'" % [symbol])
        i.scope = q.scope 
    i.scope = origScope

  .symbol("inspect") do (i: In):
    var scope: MinValue
    i.reqQuotation scope
    var symbols = newSeq[MinValue](0)
    for s in scope.scope.symbols.keys:
      symbols.add s.newVal
    i.push symbols.newVal

  .symbol("raise") do (i: In):
    var err: MinValue
    i.reqQuotation err
    raiseRuntime("($1) $2" % [err.qVal[0].getString, err.qVal[1].getString], err.qVal)

  .symbol("try") do (i: In):
    var prog: MinValue
    i.reqQuotation prog
    if prog.qVal.len < 2:
      raiseInvalid("Quotation must contain at least two elements")
    var code = prog.qVal[0]
    var catch = prog.qVal[1]
    var final: MinValue
    var hasFinally = false
    if prog.qVal.len > 2:
      final = prog.qVal[2]
      hasFinally = true
    if (not code.isQuotation or not catch.isQuotation) or (hasFinally and not final.isQuotation):
      raiseInvalid("Quotation must contain at least two quotations")
    i.unsafe = true
    try:
      i.unquote("<try-code>", code)
    except MinRuntimeError:
      i.unsafe = false
      let e = (MinRuntimeError)getCurrentException()
      i.push e.qVal.newVal
      i.unquote("<try-catch>", catch)
    except:
      i.unsafe = false
      let e = getCurrentException()
      i.push @[regex.replace($e.name, ":.+$", "").newVal, e.msg.newVal].newVal
      i.unquote("<try-catch>", catch)
    finally:
      if hasFinally:
        i.unquote("<try-finally>", final)

  .symbol("multiunquote") do (i: In):
    var q: MinValue
    i.reqQuotation q
    let stack = i.copystack
    proc coroutine(i: MinInterpreter, c: int, results: ptr MinStack) {.routine.} =
      i.unquote("<multiunquote>", q.qVal[c])
      results[][c] = i.stack[0]
    var results = newSeq[MinValue](q.qVal.len)
    for c in 0..q.qVal.high:
      if not q.qVal[c].isQuotation:
        raiseInvalid("Item #$1 is not a quotation" % [$(c+1)])
      var i2 = i.copy(i.filename)
      var res: MinStack = newSeq[MinValue](0)
      pRun coroutine, (i2, c, results.addr)
    waitAllRoutine()
    i.push results.newVal


  # Operations on the whole stack

  .symbol("clear") do (i: In):
    while i.stack.len > 0:
      discard i.pop

  .symbol("dump") do (i: In):
    echo i.dump

  .symbol("getstack") do (i: In):
    i.push i.stack.newVal

  .symbol("setstack") do (i: In):
    var q: MinValue
    i.reqQuotation q
    i.stack = q.qVal

  # Operations on quotations or strings

  .symbol("concat") do (i: In):
    var q1, q2: MinValue 
    i.reqTwoQuotationsOrStrings q1, q2
    if q1.isString and q2.isString:
      let s = q2.strVal & q1.strVal
      i.push newVal(s)
    else:
      let q = q2.qVal & q1.qVal
      i.push newVal(q)

  .symbol("first") do (i: In):
    var q: MinValue
    i.reqStringOrQuotation q
    if q.isQuotation:
      if q.qVal.len == 0:
        raiseOutOfBounds("Quotation is empty")
      i.push q.qVal[0]
    elif q.isString:
      if q.strVal.len == 0:
        raiseOutOfBounds("String is empty")
      i.push newVal($q.strVal[0])

  .symbol("rest") do (i: In):
    var q: MinValue
    i.reqStringOrQuotation q
    if q.isQuotation:
      if q.qVal.len == 0:
        raiseOutOfBounds("Quotation is empty")
      i.push newVal(q.qVal[1..q.qVal.len-1])
    elif q.isString:
      if q.strVal.len == 0:
        raiseOutOfBounds("String is empty")
      i.push newVal(q.strVal[1..q.strVal.len-1])

  .symbol("quote") do (i: In):
    let a = i.pop
    i.push MinValue(kind: minQuotation, qVal: @[a])
  
  .symbol("unquote") do (i: In):
    var q: MinValue
    i.reqQuotation q
    i.unquote("<unquote>", q)
  
  .symbol("append") do (i: In):
    var q: MinValue
    i.reqQuotation q
    let v = i.pop
    q.qVal.add v
    i.push q
  
  .symbol("cons") do (i: In):
    var q: MinValue
    i.reqQuotation q
    let v = i.pop
    q.qVal = @[v] & q.qVal
    i.push q

  .symbol("at") do (i: In):
    var index, q: MinValue
    i.reqIntAndQuotation index, q
    if q.qVal.len-1 < index.intVal:
      raiseOutOfBounds("Insufficient items in quotation")
    i.push q.qVal[index.intVal.int]

  .symbol("size") do (i: In):
    var q: MinValue
    i.reqStringOrQuotation q
    if q.isQuotation:
      i.push q.qVal.len.newVal
    elif q.isString:
      i.push q.strVal.len.newVal

  .symbol("contains") do (i: In):
    let v = i.pop
    var q: MinValue
    i.reqQuotation q
    i.push q.qVal.contains(v).newVal 
  
  .symbol("map") do (i: In):
    var prog, list: MinValue
    i.reqTwoQuotations prog, list
    i.push newVal(newSeq[MinValue](0))
    for litem in list.qVal:
      i.push litem
      i.unquote("<map-quotation>", prog)
      i.apply("swap") 
      i.apply("append") 
  
  .symbol("times") do (i: In):
    var t, prog: MinValue
    i.reqIntAndQuotation t, prog
    if t.intVal < 1:
      raiseInvalid("A non-zero natural number is required")
    for c in 1..t.intVal:
      i.unquote("<times-quotation>", prog)
  
  .symbol("ifte") do (i: In):
    var fpath, tpath, check: MinValue
    i.reqThreeQuotations fpath, tpath, check
    var stack = i.copystack
    i.unquote("<ifte-check>", check)
    let res = i.pop
    i.stack = stack
    if res.isBool and res.boolVal == true:
      i.unquote("<ifte-true>", tpath)
    else:
      i.unquote("<ifte-false>", fpath)
  
  .symbol("while") do (i: In):
    var d, b: MinValue
    i.reqTwoQuotations d, b
    i.push b.qVal
    i.unquote("<while-check>", b)
    var check = i.pop
    while check.isBool and check.boolVal == true:
      i.unquote("<while-quotation>", d)
      i.unquote("<while-check>", b)
      check = i.pop
  
  .symbol("filter") do (i: In):
    var filter, list: MinValue
    i.reqTwoQuotations filter, list
    var res = newSeq[MinValue](0)
    for e in list.qVal:
      i.push e
      i.unquote("<filter-check>", filter)
      var check = i.pop
      if check.isBool and check.boolVal == true:
        res.add e
    i.push res.newVal
  
  .symbol("linrec") do (i: In):
    var r2, r1, t, p: MinValue
    i.reqFourQuotations r2, r1, t, p
    proc linrec(i: In, p, t, r1, r2: var MinValue) =
      i.unquote("<linrec-predicate>", p)
      var check = i.pop
      if check.isBool and check.boolVal == true:
        i.unquote("<linrec-true>", t)
      else:
        i.unquote("<linrec-r1>", r1)
        i.linrec(p, t, r1, r2)
        i.unquote("<linrec-r2>", r2)
    i.linrec(p, t, r1, r2)
  
  .finalize()