#!/usr/bin/python
"""
# Purpose
ListManager is a widget based on `menu` which allows the handling of repetitive operations in a list.
Imagine you have a list and want to add/copy/edit/delete their elements. With this widget you will be shown the list
```
Vamos alla

Use ESC to skip


> uno : 1
dos : 2
tres : 3
cuatro : 4
==>
Confirm and exit
Cancel
(Press "/" to search)
```
Once you select one of the elements of the list, you will be promted with the action to be done to the selected element
```

uno : 1
dos : 2
> tres : 3
cuatro : 4
==>
Confirm and exit
Cancel
(Press "/" to search)

Select an action for < {'tres': 3} >


Add
Copy
Edit
Delete
> Cancel
```
You execute the action for this element (which might or not involve user interaction) and return to the list main page
till you call one of the options `confirm and exit` which returns the modified list or `cancel` which returns the original list unchanged.
If the list is empty one action can be defined as default (usually Add). We call it **null_action**
YOu can also define a **default_action** which will appear below the separator, not tied to any element of the list. Barring explicit definition, default_action will be the null_action
```
==>
Add
Confirm and exit
Cancel
(Press "/" to search)
```
The default implementation can handle simple lists and a key:value dictionary. The default actions are the shown above.
A sample of basic usage is included at the end of the source.

More sophisticaded uses can be achieved by
* changing the action list and the null_action during intialization
```
	opciones = ListManager('Vamos alla',opciones,[str(_('Add')),str(_('Delete'))],_('Add')).run()
```
* And using following methods to overwrite/define user actions and other details:
* * `reformat`. To change the appearance of the list elements
* * `action_list`. To modify the content of the action list once an element is defined. F.i. to avoid Delete to appear for certain elements, or to add/modify action based in the value of the element.
* * `exec_action` which contains the actual code to be executed when an action is selected

The contents in the base class of this methods serve for a very basic usage, and are to be taken as samples. Thus the best use of this class would be to subclass in your code

```
	class ObjectList(archinstall.ListManager):
		def __init__(prompt,list):
			self.ObjectAction = [... list of actions ...]
			self.ObjectNullAction = one ObjectAction
			super().__init__(prompt,list,ObjectActions,ObjectNullAction)
		def reformat(self):
			... beautfy the output of the list
		def action_list(self):
			... if you need some changes to the action list based on self.target
		def exec_action(self):
			if self.action == self.ObjectAction[0]:
				performFirstAction(self.target, ...)

	...
	resultList = ObjectList(prompt,originallist).run()
```

"""

from .text_input import TextInput
from .menu import Menu
from ..general import RequirementError
from os import system
from copy import copy
from typing import Union

class ListManager:
	def __init__(self,prompt :str, base_list :Union[list,dict] ,base_actions :list = None,null_action :str = None, default_action :Union[str,list] = None, header :Union[str,list] = None):
		"""
		param :prompt  Text which will appear at the header
		type param: string | DeferredTranslation

		param :base:_list list/dict of option to be shown / mainpulated
		type param: list | dict

		param base_actions an alternate list of actions to the items of the object
		type param: list

		param: null_action action which will be taken (if any) when base_list is empty
		type param: string

		param: default_action action which will be presented at the bottom of the list. Shouldn't need a target. If not present, null_action is set there.
		Both Null and Default actions can be defined outside the base_actions list, as long as they are launched in exec_action
		type param: string or list

		param: header one or more header lines for the list
		type param: string or list
		"""

		if not null_action and len(base_list) == 0:
			raise RequirementError('Data list for ListManager can not be empty if there is no null_action')

		self.prompt = prompt if prompt else _('Choose an object from the list')
		self.null_action = str(null_action)
		if not default_action:
			self.default_action = [self.null_action,]
		elif isinstance(default_action,(list,tuple)):
			self.default_action = default_action
		else:
			self.default_action = [str(default_action),]

		self.header = header if header else None
		self.cancel_action = str(_('Cancel'))
		self.confirm_action = str(_('Confirm and exit'))
		self.separator = '==>'
		self.bottom_list = [self.confirm_action,self.cancel_action]
		self.bottom_item = [self.cancel_action]
		self.base_actions = base_actions if base_actions else [str(_('Add')),str(_('Copy')),str(_('Edit')),str(_('Delete'))]

		self.base_data = base_list
		self.data = copy(base_list) # as refs, changes are immediate
		# default values for the null case
		self.target = None
		self.action = self.null_action
		if len(self.data) == 0:
			self.exec_action()

	def run(self):
		while True:
			self.data_formatted = self.reformat()
			options = self.data_formatted + [self.separator]
			if self.default_action:
				options += self.default_action
			options += self.bottom_list
			system('clear')
			target = Menu(self.prompt,
				options,
				sort=False,
				clear_screen=False,
				clear_menu_on_exit=False,
				header=self.header).run()

			if not target or target in self.bottom_list:
				break
			if target and target == self.separator:
				continue
			if target and target in self.default_action:
				self.action = target
				target = None
				self.target = None
				self.exec_action()
				continue
			if isinstance(self.data,dict):
				key = list(self.data.keys())[self.data_formatted.index(target)]
				self.target = {key: self.data[key]}
			else:
				self.target = self.data[self.data_formatted.index(target)]
			# Possible enhacement. If run_actions returns false a message line indicating the failure
			self.run_actions(target)

		if not target or target == self.cancel_action:  # TODO dubious
			return self.base_data  # return the original list
		else:
			return self.data

	def run_actions(self,prompt_data=None):
		options = self.action_list() + self.bottom_item
		prompt = _("Select an action for < {} >").format(prompt_data if prompt_data else self.target)
		self.action = Menu(prompt,
				options,
				sort=False,
				skip=False,
				clear_screen=False,
				clear_menu_on_exit=False,
				preset_values=self.bottom_item,
				show_search_hint=False).run()
		if self.action == self.cancel_action:
			return False
		else:
			return self.exec_action()
	"""
	The following methods are expected to be overwritten by the user if the needs of the list are beyond the simple case
	"""

	def reformat(self):
		"""
		method to get the data in a format suitable to be shown
		It is executed once for run loop and processes the whole self.data structure
		"""
		if isinstance(self.data,dict):
			return list(map(lambda x:f"{x} : {self.data[x]}",self.data))
		else:
			return list(map(lambda x:str(x),self.data))

	def action_list(self):
		"""
		can define alternate action list or customize the list  for each item.
		Executed after any item is selected, contained in self.target
		"""
		return self.base_actions

	def exec_action(self):
		"""
		what's executed one an item (self.target) and one action (self.action) is selected.
		Should be overwritten by the user
		The result is expected to update self.data in this routine, else it is ignored
		The basic code is useful for simple lists and dictionaries (key:value pairs, both strings)
		"""
		# TODO guarantee unicity
		if isinstance(self.data,list):
			if self.action == str(_('Add')):
				self.target = TextInput(_('Add :'),None).run()
				self.data.append(self.target)
			if self.action == str(_('Copy')):
				while True:
					target = TextInput(_('Copy to :'),self.target).run()
					if target != self.target:
						self.data.append(self.target)
						break
			elif self.action == str(_('Edit')):
				tgt = self.target
				idx = self.data.index(self.target)
				result = TextInput(_('Edite :'),tgt).run()
				self.data[idx] = result
			elif self.action == str(_('Delete')):
				del self.data[self.data.index(self.target)]
		elif isinstance(self.data,dict):
			# allows overwrites
			if self.target:
				origkey,origval = list(self.target.items())[0]
			else:
				origkey = None
				origval = None
			if self.action == str(_('Add')):
				key = TextInput(_('Key :'),None).run()
				value = TextInput(_('Value :'),None).run()
				self.data[key] = value
			if self.action == str(_('Copy')):
				while True:
					key = TextInput(_('Copy to new key:'),origkey).run()
					if key != origkey:
						self.data[key] = origval
						break
			elif self.action == str(_('Edit')):
				value = TextInput(_(f'Edit {origkey} :'),origval).run()
				self.data[origkey] = value
			elif self.action == str(_('Delete')):
				del self.data[origkey]

		return True


if __name__ == "__main__":
	# opciones = ['uno','dos','tres','cuatro']
	# opciones = archinstall.list_mirrors()
	opciones = {'uno':1,'dos':2,'tres':3,'cuatro':4}
	acciones = ['editar','borrar','añadir']
	cabecera = ["En Jaen Donde Resido","Vive don Lope de Sosa"]
	opciones = ListManager('Vamos alla',opciones,None,_('Add'),default_action=acciones,header=cabecera).run()
	print(opciones)