"""Settings dialog: the shared SaraSuite settings (with export/import),
SaraTune's own, and Music mode's library. Laid out like SaraFem's and
SaraSuite's Settings (a category list on the left, the chosen category on the
right)."""

import os
import subprocess
from pathlib import Path
from typing import Callable

import flet as ft
import tomlkit

from Core import (
    AppConfig, AvailableThemes, BundledFontFamily, ChildEnvironment, ChipButtonStyle, ExportSettings, Home,
    ImportSettings, IsWindows, LoadSharedSettings, Palette, PlaylistsDir, SharedSettings,
)
from Widgets import App

DialogWidth = 700
DialogHeight = 520
CategoryListWidth = 150
RestartNote = "Theme, font and title bar changes apply the next time SaraTune starts."
Modes = ["Music", "Audio"]


def _Note(Text: str) -> ft.Text:
    return ft.Text(Text, color=Palette.Overlay0, size=12)


def _WindowsFonts() -> set[str]:
    """Font families from the system and per-user Fonts registry keys
    ("Arial Bold (TrueType)" -> "Arial")."""
    import re
    import winreg

    Families: set[str] = set()
    Key = r"SOFTWARE\Microsoft\Windows NT\CurrentVersion\Fonts"
    for Root in (winreg.HKEY_LOCAL_MACHINE, winreg.HKEY_CURRENT_USER):
        try:
            with winreg.OpenKey(Root, Key) as Fonts:
                Index = 0
                while True:
                    try:
                        Name = winreg.EnumValue(Fonts, Index)[0]
                    except OSError:
                        break
                    Index += 1
                    Name = re.sub(r"\s*\(.*\)$", "", Name)
                    Name = re.sub(r"\s+(Bold|Italic|Light|Semibold|SemiBold|Black|Regular|Medium|Thin)\b.*$", "", Name)
                    if Name and "&" not in Name:
                        Families.add(Name.strip())
        except OSError:
            continue
    return Families


def _Fonts() -> list[str]:
    """Installed font families (fontconfig, or the registry on Windows), with
    the bundled font first."""
    if IsWindows:
        Families = _WindowsFonts()
        Families.discard(BundledFontFamily)
        return [BundledFontFamily] + sorted(Families, key=str.lower)
    try:
        Result = subprocess.run(
            ["fc-list", ":", "family"], capture_output=True, text=True, timeout=5, env=ChildEnvironment(),
        )
        Families = {Line.split(",")[0].strip() for Line in Result.stdout.splitlines() if Line.strip()}
    except (OSError, subprocess.SubprocessError):
        Families = set()
    Families.discard(BundledFontFamily)
    return [BundledFontFamily] + sorted(Families, key=str.lower)


def _NumberField(Label: str, Value: int) -> ft.TextField:
    return ft.TextField(label=Label, value=str(Value), keyboard_type=ft.KeyboardType.NUMBER)


def _ReadInt(Field: ft.TextField, Fallback: int, Minimum: int) -> int:
    try:
        return max(Minimum, int(Field.value))
    except (TypeError, ValueError):
        return Fallback  # keep the previous value rather than crash on bad input


def ShowSettingsDialog(TheApp: App, OnSaved: Callable[[bool], None], OnClearCache: Callable[[], None]) -> None:
    """OnSaved(FoldersChanged) runs after saving; OnClearCache empties the
    library cache (Music mode rescans)."""
    Page = TheApp.Page
    Config: AppConfig = TheApp.Config
    Themes = AvailableThemes()
    Fonts = _Fonts()

    def ThemePicker(Value: str) -> ft.Dropdown:
        Names = Themes if Value in Themes else [Value] + Themes
        return ft.Dropdown(value=Value, label="Theme", options=[ft.DropdownOption(key=Name, text=Name) for Name in Names])

    def FontPicker(Value: str) -> ft.Dropdown:
        # Type to filter the long list.
        Names = Fonts if Value in Fonts else [Value] + Fonts
        return ft.Dropdown(
            value=Value, label="Font", editable=True, enable_filter=True, menu_height=320,
            options=[ft.DropdownOption(key=Name, text=Name) for Name in Names],
        )

    # SaraSuite: ~/.config/SaraSuite/Config.toml, read by every SaraSuite program.
    Shared = LoadSharedSettings(Config)
    UseSharedSwitch = ft.Switch(label="SaraTune uses these shared settings", value=Config.UseSharedSettings)
    SharedTheme = ThemePicker(Shared.Theme)
    SharedFont = FontPicker(Shared.FontFamily)
    SharedTitleBar = ft.Switch(label="Hide window title bar", value=Shared.HideWindowTitleBar)
    SettingsFileField = ft.TextField(value=str(Home / "SaraTune-Settings.toml"), label="Settings file path")

    # SaraTune's own appearance, only used with shared settings off.
    OwnTheme = ThemePicker(Config.Theme)
    OwnFont = FontPicker(Config.FontFamily)
    OwnTitleBar = ft.Switch(label="Hide window title bar", value=Config.HideWindowTitleBar)
    OwnAppearance = ft.Column(
        [_Note("SaraTune's own appearance, used when shared settings are off"), OwnTheme, OwnFont, OwnTitleBar],
        spacing=12,
        disabled=Config.UseSharedSettings,
        opacity=0.5 if Config.UseSharedSettings else 1,
    )

    def OnUseSharedChanged(e) -> None:
        OwnAppearance.disabled = UseSharedSwitch.value
        OwnAppearance.opacity = 0.5 if UseSharedSwitch.value else 1
        OwnAppearance.update()

    UseSharedSwitch.on_change = OnUseSharedChanged

    StartMode = ft.Dropdown(
        label="Start in", value=Config.StartMode if Config.StartMode in Modes else "Music",
        options=[ft.DropdownOption(key=Name, text=f"{Name} mode") for Name in Modes],
    )
    SeekField = _NumberField("Arrow keys seek by (seconds, Audio mode)", Config.SeekSeconds)
    AdvanceSwitch = ft.Switch(label="Audio mode plays the next file in the folder when one ends",
                              value=Config.AudioAutoAdvance)

    # Music: one folder per line, plus a Browse button that adds a line.
    FoldersField = ft.TextField(label="Music folders (one per line)", value="\n".join(Config.MusicFolders),
                                multiline=True, min_lines=3, max_lines=6, expand=True)

    async def AddFolder(e) -> None:
        Chosen = await TheApp.Picker.get_directory_path(dialog_title="Add a music folder")
        if Chosen:
            Lines = [Line for Line in (FoldersField.value or "").splitlines() if Line.strip()]
            if Chosen not in Lines:
                FoldersField.value = "\n".join(Lines + [Chosen])
                FoldersField.update()

    ScanSwitch = ft.Switch(label="Look for new and changed files every start", value=Config.ScanOnStart)
    SessionSwitch = ft.Switch(label="Remember the queue and position between runs", value=Config.RememberSession)

    def ClearCache(e) -> None:
        Page.pop_dialog()
        OnClearCache()

    def OnExport(e) -> None:
        PathText = (SettingsFileField.value or "").strip()
        if not PathText:
            return
        try:
            ExportSettings(Config, Path(PathText).expanduser())
        except OSError as Error:
            TheApp.Notify(f"Couldn't export settings: {Error}", "error")
            return
        TheApp.Notify("Settings exported.", "success")

    def OnImport(e) -> None:
        PathText = (SettingsFileField.value or "").strip()
        if not PathText:
            return
        OldFolders = list(Config.MusicFolders)
        try:
            ImportSettings(Config, Path(PathText).expanduser())
        except (OSError, tomlkit.exceptions.TOMLKitError) as Error:
            TheApp.Notify(f"Couldn't import settings: {Error}", "error")
            return
        # The open dialog still shows the pre-import values; closing it
        # rather than leaving a stale Save that would overwrite the import.
        Page.pop_dialog()
        OnSaved(Config.MusicFolders != OldFolders)
        TheApp.Notify("Settings imported. Reopen Settings to see them; restart for Theme/Font/Title bar.", "success")

    Categories: dict[str, ft.Control] = {
        "SaraSuite": ft.Column(
            [
                _Note("Shared by every SaraSuite program (~/.config/SaraSuite/Config.toml). "
                      "Other programs pick changes up the next time they start."),
                UseSharedSwitch,
                ft.Divider(height=1, color=Palette.Surface1),
                SharedTheme,
                SharedFont,
                SharedTitleBar,
                ft.Divider(height=1, color=Palette.Surface1),
                _Note("Export/import settings as one file: this tab's shared settings plus everything else "
                      "in Settings. Same format as SaraFem's."),
                SettingsFileField,
                ft.Row([
                    ft.OutlinedButton(content="Export", style=ChipButtonStyle(), on_click=OnExport),
                    ft.OutlinedButton(content="Import", style=ChipButtonStyle(), on_click=OnImport),
                ]),
            ],
            spacing=12,
            scroll=ft.ScrollMode.AUTO,
        ),
        "General": ft.Column(
            [
                StartMode,
                _Note("Opening files with SaraTune (e.g. from a file manager) always starts in Audio mode."),
                SeekField,
                AdvanceSwitch,
                ft.Divider(height=1, color=Palette.Surface1),
                OwnAppearance,
            ],
            spacing=12,
            scroll=ft.ScrollMode.AUTO,
        ),
        "Music": ft.Column(
            [
                _Note("Music mode's library is every audio file below these folders."),
                ft.Row([FoldersField, ft.IconButton(ft.Icons.CREATE_NEW_FOLDER_OUTLINED, tooltip="Add a folder",
                                                    on_click=AddFolder)],
                       vertical_alignment=ft.CrossAxisAlignment.START),
                ScanSwitch,
                SessionSwitch,
                ft.Divider(height=1, color=Palette.Surface1),
                _Note("Playlists are kept in ~/.config/SaraSuite/SaraTune/Playlists/, one TOML file each. "
                      "The library's tags and cover thumbnails are only a cache."),
                ft.Row([
                    ft.OutlinedButton(content="Open playlists folder", style=ChipButtonStyle(),
                                      on_click=lambda e: (PlaylistsDir.mkdir(parents=True, exist_ok=True),
                                                          TheApp.OpenFolder(str(PlaylistsDir)))),
                    ft.OutlinedButton(content="Clear cache and rescan", style=ChipButtonStyle(Palette.Yellow),
                                      on_click=ClearCache),
                ], wrap=True),
            ],
            spacing=12,
            scroll=ft.ScrollMode.AUTO,
        ),
    }

    DetailArea = ft.Container(Categories["General"], expand=True, padding=ft.Padding.only(left=12))
    CategoryTiles: dict[str, ft.ListTile] = {}

    def SelectCategory(Name: str) -> None:
        for CategoryName, Tile in CategoryTiles.items():
            Tile.selected = CategoryName == Name
        DetailArea.content = Categories[Name]
        DetailArea.update()
        CategoryList.update()

    for Name in Categories:
        CategoryTiles[Name] = ft.ListTile(
            title=Name,
            selected=Name == "General",
            selected_tile_color=Palette.Surface1,
            selected_color=Palette.Mauve,
            on_click=lambda e, n=Name: SelectCategory(n),
        )
    CategoryList = ft.Column(list(CategoryTiles.values()), spacing=0, scroll=ft.ScrollMode.AUTO)

    def Save(e) -> None:
        OldFolders = list(Config.MusicFolders)
        Config.UseSharedSettings = UseSharedSwitch.value
        Config.Theme = OwnTheme.value or Config.Theme
        Config.FontFamily = OwnFont.value or Config.FontFamily
        Config.HideWindowTitleBar = OwnTitleBar.value
        Config.StartMode = StartMode.value or Config.StartMode
        Config.SeekSeconds = _ReadInt(SeekField, Config.SeekSeconds, 1)
        Config.AudioAutoAdvance = AdvanceSwitch.value
        Config.MusicFolders = [os.path.expanduser(Line.strip()) for Line in (FoldersField.value or "").splitlines()
                               if Line.strip()]
        Config.ScanOnStart = ScanSwitch.value
        Config.RememberSession = SessionSwitch.value
        Config.Save()
        SharedSettings(
            Theme=SharedTheme.value,
            FontFamily=SharedFont.value or Shared.FontFamily,
            HideWindowTitleBar=SharedTitleBar.value,
        ).Save()
        Page.pop_dialog()
        OnSaved(Config.MusicFolders != OldFolders)
        TheApp.Notify("Settings saved.", "success")

    Page.show_dialog(ft.AlertDialog(
        title="Settings",
        content=ft.Column(
            [
                ft.Row(
                    [
                        ft.Container(
                            CategoryList, width=CategoryListWidth, bgcolor=Palette.Surface0, border_radius=4, padding=4,
                        ),
                        DetailArea,
                    ],
                    expand=True,
                    vertical_alignment=ft.CrossAxisAlignment.STRETCH,
                ),
                ft.Divider(height=1, color=Palette.Surface1),
                _Note(RestartNote),
            ],
            width=DialogWidth,
            height=DialogHeight,
        ),
        actions=[
            ft.OutlinedButton(content="Cancel", style=ChipButtonStyle(), on_click=lambda e: Page.pop_dialog()),
            ft.OutlinedButton(content="Save", style=ChipButtonStyle(), on_click=Save),
        ],
    ))