"""Default landing page for the pgt TUI."""

from __future__ import annotations

from typing import Literal

from unicurses import (  # type: ignore[import-untyped]
	A_BOLD,
	A_REVERSE,
	KEY_RESIZE,
)

from pygittools.tui.branches import current_branch_name
from pygittools.tui.changes_list import ChangesList
from pygittools.tui.commit_draft import load_commit_draft
from pygittools.tui.draw import draw_line
from pygittools.tui.input_context import InputMode, input_context, nav_context
from pygittools.tui.types import Page, PageAction, PageContext, PageResult

_HEADER_ROWS = 5
_REPO_ROW = 2
_BRANCH_ROW = 3
_HeaderFocus = Literal["changes", "repo", "branch"]


class HomePage:
	title = "pgt"

	def __init__(self) -> None:
		self._ctx: PageContext | None = None
		self._changes = ChangesList()
		self._header_focus: _HeaderFocus = "changes"
		self._input_mode: InputMode = nav_context()

	@property
	def header_focus(self) -> _HeaderFocus:
		return self._header_focus

	def set_header_focus(self, focus: _HeaderFocus) -> None:
		self._header_focus = focus

	@property
	def page_context(self) -> PageContext | None:
		return self._ctx

	@property
	def changes(self) -> ChangesList:
		return self._changes

	def on_enter(self, ctx: PageContext) -> None:
		self._ctx = ctx
		self._header_focus = "changes"
		self._input_mode = nav_context()
		self._changes.set_commit_message(load_commit_draft(ctx.repo_path, ctx.repo))
		self._changes.refresh(ctx.repo)

	def status_text(self) -> str:
		return self._input_mode.status_hint(self)

	def draw(self, stdscr: int, height: int, width: int) -> None:
		del stdscr
		ctx = self._ctx
		if ctx is None:
			return

		self._changes.refresh(ctx.repo)
		worktree = ctx.repo.workdir or str(ctx.repo_path)
		branch = current_branch_name(ctx.repo)
		header_lines: list[tuple[str, int]] = [
			("pgt", A_BOLD),
			("", 0),
			(f"Repository: {worktree}", 0),
			(f"Branch: {branch}", 0),
			("", 0),
		]
		for row, (text, attr) in enumerate(header_lines):
			if row >= height:
				break
			if row == _REPO_ROW and self._header_focus == "repo":
				attr = A_REVERSE
			if row == _BRANCH_ROW and self._header_focus == "branch":
				attr = A_REVERSE
			draw_line(row, 0, text, width, attr)

		list_height = max(0, height - _HEADER_ROWS)
		if list_height > 0 and height > _HEADER_ROWS:
			self._changes.draw(_HEADER_ROWS, list_height, width, highlight=self._header_focus == "changes")

	def handle_key(self, key: int) -> PageResult:
		if key in (ord("q"), ord("Q")):
			return PageResult(action=PageAction.QUIT)
		if key == KEY_RESIZE:
			return PageResult()

		dispatch = self._input_mode.dispatch_key(self, key)
		if dispatch.next_mode == "input":
			self._input_mode = input_context()
		elif dispatch.next_mode == "nav":
			self._input_mode = nav_context()
		if dispatch.page_result is not None:
			return dispatch.page_result
		return PageResult()


def home_page() -> Page:
	return HomePage()