from subprocess import Popen, PIPE, STDOUT
from method import Method, Argument
from method.vc import VcBlame
import re

try:
    from mercurial import hg, ui
    from mercurial import commands as hgc
    has_hg = True
except ImportError:
    has_hg = False

class HgBase(object):
    def _hg_check(self, w):
        if not has_hg:
            w.set_error("Mercurial is not installed")
            return False
        elif not hasattr(w.buffer, 'path'):
            w.set_error("Buffer has no corresponding file")
            return False
        else:
            return True
    def _hg_init(self):
        ui_imp = ui.ui(verbose=True)
        ui_imp.pushbuffer()
        repo = hg.repository(ui=ui_imp, path='.')
        return ui_imp, repo

class HgBlame(VcBlame, HgBase):
    """Show buffer annotated with hg metadata"""
    line_re = re.compile(r'^ *(?P<user>[^ ]+) (?P<rev>\d+) (?P<date>\d{4}-\d{2}-\d{2}): (?P<content>.*)\n$')
    prefix_fmt = '[b:d:*]%(rev)-5s [c:d:*]%(user)-10s [b:d:*]%(date)10s[d:d:*]'
    _is_method = True
    def _open_pipe(self, w, **vargs):
        cmd = ("hg", 'blame', '-nudq', w.buffer.path)
        return Popen(cmd, stdin=PIPE, stdout=PIPE, stderr=PIPE)

class HgBlame2(Method, HgBase):
    def _execute(self, w, **vargs):
        if not self._hg_check(w):
            return
        ui_imp, repo = self._hg_init()
        hgc.identify(ui_imp, repo, w.buffer.path)
        hgc.annotate(ui_imp, repo, w.buffer.path, user=None, date=None, rev=None)
        s = ''.join(ui_imp.popbuffer())
        w.application.data_buffer('*Blame*', s, switch_to=True)

class HgLog(Method, HgBase):
    """Show hg log for this buffer"""
    def _execute(self, w, **vargs):
        if not self._hg_check(w):
            return
        ui_imp, repo = self._hg_init()
        hgc.log(ui_imp, repo, user=None, rev=None, date=None)
        s = ''.join(ui_imp.popbuffer())
        w.application.data_buffer('*Log*', s, switch_to=True)

class HgDiff(Method, HgBase):
    """Diff the current file with the version in Mercurial"""
    def _execute(self, w, **vargs):
        if not self._hg_check(w):
            return
        ui_imp, repo = self._hg_init()
        hgc.diff(ui_imp, repo, w.buffer.path)
        s = ''.join(ui_imp.popbuffer())
        w.application.data_buffer("*Diff*", s, switch_to=True, modename='diff')