"""Grep dialog for Find in Files functionality.

 Inherits from SearchDialogBase for GUI and uses searchengine
 to prepare search pattern.
"""
import fnmatch
import os
import sys

from tkinter import StringVar, BooleanVar
from tkinter.ttk import Checkbutton # Frame imported in ...Base

from idlelib.searchbase import SearchDialogBase
from idlelib import searchengine

# Importing OutputWindow here fails due to import loop
# EditorWindow -> GrepDialog -> OutputWindow -> EditorWindow


def grep(text, io=None, flist=None):
 """Open the Find in Files dialog.

 Module-level function to access the singleton GrepDialog
 instance and open the dialog. If text is selected, it is
 used as the search phrase; otherwise, the previous entry
 is used.

 Args:
 text: Text widget that contains the selected text for
 default search phrase.
 io: iomenu.IOBinding instance with default path to search.
 flist: filelist.FileList instance for OutputWindow parent.
 """
 root = text._root()
 engine = searchengine.get(root)
 if not hasattr(engine, "_grepdialog"):
 engine._grepdialog = GrepDialog(root, engine, flist)
 dialog = engine._grepdialog
 searchphrase = text.get("sel.first", "sel.last")
 dialog.open(text, searchphrase, io)


def walk_error(msg):
 "Handle os.walk error."
 print(msg)


def findfiles(folder, pattern, recursive):
 """Generate file names in dir that match pattern.

 Args:
 folder: Root directory to search.
 pattern: File pattern to match.
 recursive: True to include subdirectories.
 """
 for dirpath, _, filenames in os.walk(folder, onerror=walk_error):
 yield from (os.path.join(dirpath, name)
 for name in filenames
 if fnmatch.fnmatch(name, pattern))
 if not recursive:
 break


class GrepDialog(SearchDialogBase):
 "Dialog for searching multiple files."

 title = "Find in Files Dialog"
 icon = "Grep"
 needwrapbutton = 0

 def __init__(self, root, engine, flist):
 """Create search dialog for searching for a phrase in the file system.

 Uses SearchDialogBase as the basis for the GUI and a
 searchengine instance to prepare the search.

 Attributes:
 flist: filelist.Filelist instance for OutputWindow parent.
 globvar: String value of Entry widget for path to search.
 globent: Entry widget for globvar. Created in
 create_entries().
 recvar: Boolean value of Checkbutton widget for
 traversing through subdirectories.
 """
 super().__init__(root, engine)
 self.flist = flist
 self.globvar = StringVar(root)
 self.recvar = BooleanVar(root)

 def open(self, text, searchphrase, io=None):
 """Make dialog visible on top of others and ready to use.

 Extend the SearchDialogBase open() to set the initial value
 for globvar.

 Args:
 text: Multicall object containing the text information.
 searchphrase: String phrase to search.
 io: iomenu.IOBinding instance containing file path.
 """
 SearchDialogBase.open(self, text, searchphrase)
 if io:
 path = io.filename or ""
 else:
 path = ""
 dir, base = os.path.split(path)
 head, tail = os.path.splitext(base)
 if not tail:
 tail = ".py"
 self.globvar.set(os.path.join(dir, "*" + tail))

 def create_entries(self):
 "Create base entry widgets and add widget for search path."
 SearchDialogBase.create_entries(self)
 self.globent = self.make_entry("In files:", self.globvar)[0]

 def create_other_buttons(self):
 "Add check button to recurse down subdirectories."
 btn = Checkbutton(
 self.make_frame()[0], variable=self.recvar,
 text="Recurse down subdirectories")
 btn.pack(side="top", fill="both")

 def create_command_buttons(self):
 "Create base command buttons and add button for Search Files."
 SearchDialogBase.create_command_buttons(self)
 self.make_button("Search Files", self.default_command, isdef=True)

 def default_command(self, event=None):
 """Grep for search pattern in file path. The default command is bound
 to <Return>.

 If entry values are populated, set OutputWindow as stdout
 and perform search. The search dialog is closed automatically
 when the search begins.
 """
 prog = self.engine.getprog()
 if not prog:
 return
 path = self.globvar.get()
 if not path:
 self.top.bell()
 return
 from idlelib.outwin import OutputWindow # leave here!
 save = sys.stdout
 try:
 sys.stdout = OutputWindow(self.flist)
 self.grep_it(prog, path)
 finally:
 sys.stdout = save

 def grep_it(self, prog, path):
 """Search for prog within the lines of the files in path.

 For the each file in the path directory, open the file and
 search each line for the matching pattern. If the pattern is
 found, write the file and line information to stdout (which
 is an OutputWindow).

 Args:
 prog: The compiled, cooked search pattern.
 path: String containing the search path.
 """
 folder, filepat = os.path.split(path)
 if not folder:
 folder = os.curdir
 filelist = sorted(findfiles(folder, filepat, self.recvar.get()))
 self.close()
 pat = self.engine.getpat()
 print(f"Searching {pat!r} in {path} ...")
 hits = 0
 try:
 for fn in filelist:
 try:
 with open(fn, errors='replace') as f:
 for lineno, line in enumerate(f, 1):
 if line[-1:] == '\n':
 line = line[:-1]
 if prog.search(line):
 sys.stdout.write(f"{fn}: {lineno}: {line}\n")
 hits += 1
 except OSError as msg:
 print(msg)
 print(f"Hits found: {hits}\n(Hint: right-click to open locations.)"
 if hits else "No hits.")
 except AttributeError:
 # Tk window has been closed, OutputWindow.text = None,
 # so in OW.write, OW.text.insert fails.
 pass


def _grep_dialog(parent): # htest #
 from tkinter import Toplevel, Text, SEL, END
 from tkinter.ttk import Frame, Button
 from idlelib.pyshell import PyShellFileList

 top = Toplevel(parent)
 top.title("Test GrepDialog")
 x, y = map(int, parent.geometry().split('+')[1:])
 top.geometry(f"+{x}+{y + 175}")

 flist = PyShellFileList(top)
 frame = Frame(top)
 frame.pack()
 text = Text(frame, height=5)
 text.pack()

 def show_grep_dialog():
 text.tag_add(SEL, "1.0", END)
 grep(text, flist=flist)
 text.tag_remove(SEL, "1.0", END)

 button = Button(frame, text="Show GrepDialog", command=show_grep_dialog)
 button.pack()

if __name__ == "__main__":
 from unittest import main
 main('idlelib.idle_test.test_grep', verbosity=2, exit=False)

 from idlelib.idle_test.htest import run
 run(_grep_dialog)