""" error handling features, just a way of displaying errors
"""

from pypy.tool.ansi_print import ansi_log, raise_nicer_exception
from pypy.objspace.flow.model import Constant, Variable
import sys

import py
log = py.log.Producer("error") 
py.log.setconsumer("error", ansi_log) 

SHOW_TRACEBACK = False
SHOW_ANNOTATIONS = True
SHOW_DEFAULT_LINES_OF_CODE = 0

from pypy.interpreter.pytraceback import offset2lineno
import traceback

def source_lines(graph, block, operindex=None, offset=None, long=False, \
    show_lines_of_code=SHOW_DEFAULT_LINES_OF_CODE):
    if block is not None:
        if block is graph.returnblock:
            return ['<return block>']
    try:
        source = graph.source
    except AttributeError:
        return ['no source!']
    else:
        graph_lines = source.split("\n")
        if offset is not None:
            linestart = offset2lineno(graph.func.func_code, offset)
            linerange = (linestart, linestart)
            here = None
        else:
            if block is None or not block.operations:
                return []
            def toline(operindex):
                return offset2lineno(graph.func.func_code, block.operations[operindex].offset)
            if operindex is None:
                linerange =  (toline(0), toline(-1))
                if not long:
                    return ['?']
                here = None
            else:
                operline = toline(operindex)
                if long:
                    linerange =  (toline(0), toline(-1))
                    here = operline
                else:
                    linerange = (operline, operline)
                    here = None
        lines = ["Happened at file %s line %d" % (graph.filename, here or linerange[0]), ""]
        for n in range(max(0, linerange[0]-show_lines_of_code), \
            min(linerange[1]+1+show_lines_of_code, len(graph_lines)+graph.startline)):
            if n == here:
                prefix = '==> '
            else:
                prefix = '    '
            lines.append(prefix + graph_lines[n-graph.startline])
        lines.append("")
        return lines

class FlowingError(Exception):
    pass

class AnnotatorError(Exception):
    pass

class NoSuchAttrError(Exception):
    pass

def gather_error(annotator, block, graph):
    msg = [""]
    msg.append('-+' * 30)
    from pypy.annotation import model
    msg.append("Blocked block -- operation cannot succeed")
    if model.DEBUG:
        _, _, operindex = annotator.why_not_annotated[block][1].break_at
    else:
        # guess the blocked operation by the fact that its return value is
        # not annotated
        for operindex in range(len(block.operations)):
            if block.operations[operindex].result not in annotator.bindings:
                break
        else:
            operindex = None

    if operindex is not None:
        oper = block.operations[operindex]
        msg.append(" " + str(oper))
    else:
        oper = None
        msg.append(" (inconsistency - the block is fully annotated??)")
    msg += source_lines(graph, block, operindex, long=True)
    if oper is not None:
        if SHOW_ANNOTATIONS:
            msg.append("Known variable annotations:")
            for arg in oper.args + [oper.result]:
                if isinstance(arg, Variable):
                    try:
                        msg.append(" " + str(arg) + " = " + str(annotator.binding(arg)))
                    except KeyError:
                        pass
        if model.DEBUG and SHOW_TRACEBACK:
            msg.extend(traceback.format_exception(*annotator.why_not_annotated[block]))
    return "\n".join(msg)

def format_blocked_annotation_error(annotator, blocked_blocks):
    text = []
    for block, graph in blocked_blocks.items():
        text.append(gather_error(annotator, block, graph))
    return '\n'.join(text)

def format_simple_call(annotator, oper, what, msg):
    msg.append("Simple call of incompatible family:")
    try:
        descs = annotator.bindings[oper.args[0]].descriptions
    except (KeyError, AttributeError), e:
        msg.append("      (%s getting at the binding!)" % (
            e.__class__.__name__,))
        return
    for desc in descs.keys():
        func = desc.pyobj
        if func is None:
            r = repr(desc)
        else:
            r = "function %s <%s, line %s>" % (func.func_name,
                   func.func_code.co_filename, func.func_code.co_firstlineno)
        msg.append("  %s returning" % (r,))
        if hasattr(desc, 'getuniquegraph'):
            graph = desc.getuniquegraph()
            r = annotator.binding(graph.returnblock.inputargs[0],
                                  "(no annotation)")
        else:
            r = '?'
        msg.append("      %s" % (r,))
        msg.append("")

def format_someobject_error(annotator, position_key, what, s_value, called_from_graph, binding=""):
    #block = getattr(annotator, 'flowin_block', None) or block
    msg = ["annotation of %r degenerated to SomeObject()" % (what,)]
    if position_key is not None:
        graph, block, operindex = position_key
        if operindex is not None:
            oper = block.operations[operindex]
            if oper.opname == 'simple_call':
                format_simple_call(annotator, oper, what, msg)
            else:
                msg.append(str(oper))
        else:
            msg.append("at the start of the block with input arguments:")
            for v in block.inputargs:
                s_v = annotator.binding(v, "(no annotation)")
                msg.append("%8s: %s" % (v, s_v))
        msg.append('')
        msg += source_lines(graph, block, operindex, long=True)
        
    if called_from_graph is not None:
        msg.append(".. called from %r" % (called_from_graph,))
    if s_value.origin is not None:
        msg.append(".. SomeObject() origin: %s" % (
            annotator.whereami(s_value.origin),))
    msg.append("Previous annotation:")
    msg.append("  " + str(binding))
    return "\n".join(msg)

def format_global_error(graph, offset, message):
    msg = []
    msg.append('-+' * 30)
    msg.append(message)
    msg += source_lines(graph, None, offset=offset)
    return "\n".join(msg)

def debug(drv, use_pdb=True):
    # XXX unify some code with pypy.translator.goal.translate
    from pypy.translator.tool.pdbplus import PdbPlusShow
    from pypy.translator.driver import log
    t = drv.translator
    class options:
        huge = 100

    tb = None
    import traceback
    errmsg = ["Error:\n"]
    exc, val, tb = sys.exc_info()
    
    errmsg.extend([" %s" % line for line in traceback.format_exception(exc, val, [])])
    block = getattr(val, '__annotator_block', None)
    if block:
        class FileLike:
            def write(self, s):
                errmsg.append(" %s" % s)
        errmsg.append("Processing block:\n")
        t.about(block, FileLike())
    log.ERROR(''.join(errmsg))

    log.event("start debugger...")

    if use_pdb:
        pdb_plus_show = PdbPlusShow(t)
        pdb_plus_show.start(tb)