"""Standalone SaraTag Book-tag panel. Split out from Preview.py (Bugs/Minor:
"SaraTag only shows in preview pane") so it can be shown/hidden and positioned
independently — see AppConfig.ShowTags / TagsPosition / TagsLayout."""

from pathlib import Path
from typing import Optional

import flet as ft

from Books import ReadBookForFile
from Core import AppConfig, Palette

# Fixedsys Excelsior is fixed-width, so a per-character estimate is accurate
# enough to size chips without a real text-measurement API.
EstimatedCharWidth = 7.5
ChipPadding = 32


def _EstimateChipWidth(Label: str, Config: AppConfig) -> Optional[float]:
    if not Config.TagMinWidth and not Config.TagMaxWidth:
        return None  # let the chip hug its content, no constraint requested
    Natural = len(Label) * EstimatedCharWidth + ChipPadding
    Lower = Config.TagMinWidth or 0
    Upper = Config.TagMaxWidth or Natural
    return max(Lower, min(Natural, Upper))


def _MakeChip(Key: str, Value, Config: AppConfig) -> ft.Chip:
    Label = f"{Key}: {Value}"
    return ft.Chip(
        label=Label,
        label_text_style=ft.TextStyle(color=Palette.Text, size=12),
        bgcolor=Palette.Surface0,
        shadow_color=Palette.Surface0,
        elevation=0,
        elevation_on_click=0,
        show_checkmark=False,
        width=_EstimateChipWidth(Label, Config),
    )


class TagPanel(ft.Container):
    def __init__(self, Config: AppConfig):
        self.Config = Config
        self.Body = ft.Column(spacing=0)
        self.Body.controls = self._BuildContent(None)

        BorderSide = ft.BorderSide(1, Palette.Surface1)
        super().__init__(
            content=self.Body,
            padding=8,
            bgcolor=Palette.Mantle,
            border=ft.Border(top=BorderSide, right=BorderSide, bottom=BorderSide, left=BorderSide),
        )

    def ShowPath(self, EntryPath: Optional[Path]) -> None:
        self.Body.controls = self._BuildContent(EntryPath)
        self.update()

    def _BuildContent(self, EntryPath: Optional[Path]) -> list[ft.Control]:
        if EntryPath is None or EntryPath.is_dir():
            return [ft.Text("No tags.", color=Palette.Overlay0, size=12)]

        Book = ReadBookForFile(EntryPath, self.Config)
        if not Book or not Book["Tags"]:
            return [ft.Text("No tags.", color=Palette.Overlay0, size=12)]

        Chips = [_MakeChip(Key, Value, self.Config) for Key, Value in Book["Tags"].items()]

        if self.Config.TagsLayout == "vertical":
            return [ft.Column(Chips, spacing=4, horizontal_alignment=ft.CrossAxisAlignment.START)]
        return [ft.Row(Chips, wrap=True, spacing=4, run_spacing=4)]