use std::collections::BTreeMap;
use std::collections::BTreeSet;

use super::FileAccessInterface;
use super::LocalFileAccessInterface;
use crate::types::IndentationLevel;
use crate::types::Object;

// TODO: Ultimately, I think we'll need most of this: https://orgmode.org/manual/In_002dbuffer-Settings.html

#[derive(Debug, Clone)]
pub struct GlobalSettings<'g, 's> {
    pub radio_targets: Vec<&'g Vec<Object<'s>>>,
    pub file_access: &'g dyn FileAccessInterface,
    pub in_progress_todo_keywords: BTreeSet<String>,
    pub complete_todo_keywords: BTreeSet<String>,
    /// Set to true to allow for plain lists using single letters as the bullet in the same way that numbers are used.
    ///
    /// Corresponds to the org-list-allow-alphabetical elisp variable.
    pub list_allow_alphabetical: bool,

    /// How many spaces a tab should be equal to.
    ///
    /// Corresponds to the tab-width elisp variable.
    pub tab_width: IndentationLevel,

    /// Whether to only allow odd headline levels.
    ///
    /// Corresponds to org-odd-levels-only elisp variable.
    pub odd_levels_only: HeadlineLevelFilter,

    /// If a headline title matches this string exactly, then that section will become a "footnote section".
    ///
    /// Corresponds to org-footnote-section elisp variable.
    pub footnote_section: &'g str,

    /// The label format for references inside src/example blocks.
    ///
    /// Corresponds to org-coderef-label-format elisp variable.
    pub coderef_label_format: &'g str,

    /// The allowed protocols for links (for example, the "https" in "https://foo.bar/").
    ///
    /// Corresponds to org-link-parameters elisp variable.
    pub link_parameters: &'g [&'g str],

    /// Link templates where the key is the document text and the value is the replacement.
    ///
    /// For example, `"foo": "bar%s"` will replace `[[foo::baz]]` with `[[barbaz]]`
    ///
    /// This is set by including #+LINK in the org-mode document.
    pub link_templates: BTreeMap<String, String>,
}

pub const DEFAULT_TAB_WIDTH: IndentationLevel = 8;

impl<'g, 's> GlobalSettings<'g, 's> {
    fn new() -> GlobalSettings<'g, 's> {
        GlobalSettings {
            radio_targets: Vec::new(),
            file_access: &LocalFileAccessInterface {
                working_directory: None,
            },
            in_progress_todo_keywords: BTreeSet::new(),
            complete_todo_keywords: BTreeSet::new(),
            list_allow_alphabetical: false,
            tab_width: DEFAULT_TAB_WIDTH,
            odd_levels_only: HeadlineLevelFilter::default(),
            footnote_section: "Footnotes",
            coderef_label_format: "(ref:%s)",
            link_parameters: &DEFAULT_ORG_LINK_PARAMETERS,
            link_templates: BTreeMap::new(),
        }
    }
}

impl<'g, 's> Default for GlobalSettings<'g, 's> {
    fn default() -> GlobalSettings<'g, 's> {
        GlobalSettings::new()
    }
}

#[derive(Debug, Clone, PartialEq)]
pub enum HeadlineLevelFilter {
    Odd,
    OddEven,
}

impl Default for HeadlineLevelFilter {
    fn default() -> Self {
        HeadlineLevelFilter::OddEven
    }
}

const DEFAULT_ORG_LINK_PARAMETERS: [&'static str; 23] = [
    "id",
    "eww",
    "rmail",
    "mhe",
    "irc",
    "info",
    "gnus",
    "docview",
    "bibtex",
    "bbdb",
    "w3m",
    "doi",
    "file+sys",
    "file+emacs",
    "shell",
    "news",
    "mailto",
    "https",
    "http",
    "ftp",
    "help",
    "file",
    "elisp",
];