#!/usr/bin/env python3

import sys

import readline

import actinide as a
import actinide.tokenizer as ak
import actinide.reader as ar
import actinide.ports as ap
import actinide.types as at

class ConsolePort(ap.Port):
    def __init__(self):
        self.line = None
        self.prompt = ">>> "

    def next_prompt(self):
        prompt, self.prompt = self.prompt, "... "
        return prompt

    def reset_prompt(self):
        self.prompt = ">>> "

    def ensure_line(self):
        if self.line == None:
            try:
                self.line = input(self.next_prompt()) + '\n'
            except EOFError:
                self.line = ''

    def peek(self, n):
        self.ensure_line()
        return self.line[:n]

    def read(self, n):
        self.ensure_line()
        result, self.line = self.line[:n], self.line[n:]
        if self.line == '':
            self.line = None
        return result

    def read_fully(self, n):
        def read_fully_():
            result = self.read(1024)
            yield result
            while result != '':
                result = self.read(1024)
                yield result
        return ''.join(read_fully_())

    def forget_input(self):
        self.line = None

def repl(session, port):
    while True:
        try:
            port.reset_prompt()
            form = session.read(port)
            if form is ar.EOF:
                print()
                return 0
            results = session.eval(form)
            print(*(session.display(result) for result in results))
        except (ak.TokenError, ar.SyntaxError) as e:
            print(e)
            port.forget_input()
        except Exception as e:
            print(e)
        except KeyboardInterrupt:
            print()
            print("(Interrupted)")

def main():
    port = ConsolePort()
    session = a.Session()

    return repl(session, port)

if __name__ == '__main__':
    sys.exit(main())