import os
import sys
import json
import argparse
import subprocess

import rich
# For some reason this is not imported by the command above.
from rich.console import Console
from rich.columns import Columns

# class make:
#     def carder(card, **kwargs):
#         def f(task):
#             return card(task, **kwargs)
#         return f

#     def stacker(stack, **kwargs):
#         def f(tasks):
#             return stack(tasks, **kwargs)
#         return f

#     def sectioner(section, **kwargs):
#         def f(tasks, field, values):
#             return section(tasks, field, values, **kwargs)
#         return f

class Widget:
    def __init__(self, order, group = None):
        self.order = order
        self.group = group

class Tasker(Widget):
    def __init__(self, show_only, order, group = None):
        super().__init__(order, group)
        self.show_only = show_only

    def __call__(self, task):
        raise NotImplementedError

class Stacker(Widget):
    def __init__(self, tasker, order, group):
        super().__init__(order, group)
        self.tasker = tasker

    def __call__(self, tasks):
        raise NotImplementedError

class Sectioner(Widget):
    def __init__(self, stacker, order, group):
        super().__init__(order, group)
        self.stacker = stacker

    def __call__(self, tasks):
        raise NotImplementedError


class task:

    class Card(Tasker):
        def __init__(self, show_only, order = None):
            super().__init__(show_only, order, group = None)

        def __call__(self, task):
            if not self.show_only:
                # Show all existing fields.
                self.show_only = task.keys()

            sid = str(task["id"])
            if ':' in task["description"]:
                short, desc = task["description"].split(":")
                title = ":".join([sid,short.strip()])
            else:
                desc = task["description"]
                title = sid

            segments = []
            for key in self.show_only:
                if key in task.keys() and key not in ["id", "description"]:
                    val = task[key]
                    segment = f"{key}: "
                    if type(val) == str:
                        segments.append(segment+t)
                    elif type(val) == list:
                        g = Columns([f"+{t}" for t in val])
                        segments.append(g)
                    else:
                        segments.append(segment+str(val))

            cols = Columns(segments)
            grp = rich.console.Group(desc.strip(), cols)
            panel = rich.panel.Panel(grp, title = title,
                title_align="left", expand = False, padding = (0,1))

            return panel

class stack:
    class Vertical(Stacker):
        def __init__(self, tasker):
            super().__init__(tasker, order = None, group = None)

        def __call__(self, tasks):
            stack = rich.table.Table(box = None, show_header = False, show_lines = False)
            stack.add_column("Tasks")
            for task in tasks:
               stack.add_row( self.tasker(task) )
            return stack

class sections:
    class Vertical(Sectioner):
        def __init__(self, stacker, order, group):
            super().__init__(stacker, order, group)

        def __call__(self, tasks):
            sections = []
            groups = self.group(tasks)
            for val in self.order():
                if val in groups:
                    sections.append( rich.panel.Panel(self.stacker(groups[val]), title = val) )
            return rich.console.Group(*sections)

class SectionSorter:
    def __call__(self):
        raise NotImplementedError

class sort:
    class Tasks:
        def make(self, tasks, field, reverse = False):
            return sorted(tasks, key = lambda t: t[field], reverse = reverse)

    class OnValues(SectionSorter):
        def __init__(self, values):
            self.values = values

        def __call__(self):
            return self.values

class Grouper:
    """Group tasks by field values."""
    def __init__(self, field):
        self.field = field

    def __call__(self, tasks):
        groups = {}
        for task in tasks:
            if self.field in task:
                if task[self.field] in groups:
                    groups[ task[self.field] ].append(task)
                else:
                    groups[ task[self.field] ] = [task]
        return groups

class group:
    class Status(Grouper):
        def __init__(self):
            super().__init__("status")

        def __call__(self, tasks):
            groups = {}
            for task in tasks:
                if "start" in task:
                    if "started" in groups:
                        groups["started"].append(task)
                    else:
                        groups["started"] = [task]
                elif self.field in task:
                    if task[self.field] in groups:
                        groups[ task[self.field] ].append(task)
                    else:
                        groups[ task[self.field] ] = [task]

            return groups


if __name__ == "__main__":

    parser = argparse.ArgumentParser(
        description="XXX",
        formatter_class=argparse.ArgumentDefaultsHelpFormatter,
    )

    main = parser.add_argument_group('Main')
    main.add_argument("-s", "--show", metavar="columns", type=str, default="id,urgency,description,tags", nargs=1,
            help="Ordered list of columns to show.")

    config = parser.add_argument_group('Config')
    config.add_argument("-d", "--data", metavar="FILE", type=str, default=".task", nargs=1,
            help="The input data file.")
    config.add_argument("--list-separator", metavar="CHARACTER", type=str, default=",", nargs=1,
            help="Separator used for lists that are passed as options arguments.")

    asked = parser.parse_args()

    env = os.environ.copy()
    env["TASKDATA"] = asked.data

    cmd = ['task', 'export']

    showed = asked.show.split(asked.list_separator)
    if not showed:
        show_only = None
    else:
        show_only = showed

    try:
        p = subprocess.Popen( " ".join(cmd),
            stdout=subprocess.PIPE,
            stderr=subprocess.PIPE,
            shell=True,
            env=env,
        )
        out, err = p.communicate()

    except subprocess.CalledProcessError as exc:
        print("ERROR:", exc.returncode, exc.output, err)
        sys.exit(exc.returncode)

    else:
        jdata = json.loads(out)
        print(json.dumps(jdata, indent=4))

        tasker = task.Card(show_only)
        stacker = stack.Vertical(tasker)
        group_by_status = group.Status()
        sort_on_values = sort.OnValues(["pending","started","completed"])
        sectioner = sections.Vertical(stacker, sort_on_values, group_by_status)

        console = Console()
        console.rule("taskwarrior-fancy")
        console.print(sectioner(jdata))