use rowan::ast::{support, AstNode};

use super::{AffiliatedKeyword, Link, Paragraph, Token};
use crate::{syntax::SyntaxKind, SyntaxElement};

impl Link {
    /// Returns link destination
    ///
    /// ```rust
    /// use orgize::{Org, ast::Link};
    ///
    /// let link = Org::parse("[[#id]]").first_node::<Link>().unwrap();
    /// assert_eq!(link.path(), "#id");
    /// let link = Org::parse("[[https://google.com]]").first_node::<Link>().unwrap();
    /// assert_eq!(link.path(), "https://google.com");
    /// let link = Org::parse("[[https://google.com][Google]]").first_node::<Link>().unwrap();
    /// assert_eq!(link.path(), "https://google.com");
    /// ```
    pub fn path(&self) -> Token {
        support::token(&self.syntax, SyntaxKind::LINK_PATH).map_or_else(
            || {
                debug_assert!(false, "link must contains LINK_PATH");
                Token::default()
            },
            |e| Token(Some(e)),
        )
    }

    /// Returns `true` if link contains description
    ///
    /// ```rust
    /// use orgize::{Org, ast::Link};
    ///
    /// let link = Org::parse("[[https://google.com]]").first_node::<Link>().unwrap();
    /// assert!(!link.has_description());
    /// let link = Org::parse("[[https://google.com][Google]]").first_node::<Link>().unwrap();
    /// assert!(link.has_description());
    /// let link = Org::parse("[[https://example.com][*abc* /abc/]]").first_node::<Link>().unwrap();
    /// assert!(link.has_description());
    /// ```
    pub fn has_description(&self) -> bool {
        self.syntax()
            .children_with_tokens()
            .any(|e| e.kind() == SyntaxKind::L_BRACKET)
    }

    /// Returns parsed description
    ///
    /// Returns empty iterator if this link doesn't contain description
    ///
    /// ```rust
    /// use orgize::{Org, ast::Link, SyntaxKind};
    ///
    /// let link = Org::parse("[[https://google.com]]").first_node::<Link>().unwrap();
    /// assert_eq!(link.description().count(), 0);
    ///
    /// let link = Org::parse("[[https://google.com][Google]]").first_node::<Link>().unwrap();
    /// let description = link.description().collect::<Vec<_>>();
    /// assert_eq!((description[0].kind(), description[0].to_string()), (SyntaxKind::TEXT, "Google".into()));
    ///
    /// let link = Org::parse("[[https://example.com][*abc* /abc/]]").first_node::<Link>().unwrap();
    /// let description = link.description().collect::<Vec<_>>();
    /// assert_eq!((description[0].kind(), description[0].to_string()), (SyntaxKind::BOLD, "*abc*".into()));
    /// assert_eq!((description[2].kind(), description[2].to_string()), (SyntaxKind::ITALIC, "/abc/".into()));
    /// ```
    pub fn description(&self) -> impl Iterator<Item = SyntaxElement> {
        self.syntax()
            .children_with_tokens()
            .skip_while(|e| e.kind() != SyntaxKind::L_BRACKET)
            .skip(1)
            .take_while(|e| e.kind() != SyntaxKind::R_BRACKET2)
    }

    /// Returns description raw string
    ///
    /// Returns empty string if this link doesn't contain description
    ///
    /// ```rust
    /// use orgize::{Org, ast::Link};
    ///
    /// let link = Org::parse("[[https://google.com]]").first_node::<Link>().unwrap();
    /// assert_eq!(link.description_raw(), "");
    /// let link = Org::parse("[[https://google.com][Google]]").first_node::<Link>().unwrap();
    /// assert_eq!(link.description_raw(), "Google");
    /// let link = Org::parse("[[https://example.com][*abc* /abc/]]").first_node::<Link>().unwrap();
    /// assert_eq!(link.description_raw(), "*abc* /abc/");
    /// ```
    pub fn description_raw(&self) -> String {
        self.description()
            .fold(String::new(), |acc, e| acc + &e.to_string())
    }

    /// Returns `true` if link is an image link
    ///
    /// ```rust
    /// use orgize::{Org, ast::Link};
    ///
    /// let link = Org::parse("[[https://google.com]]").first_node::<Link>().unwrap();
    /// assert!(!link.is_image());
    /// let link = Org::parse("[[file:/home/dominik/images/jupiter.jpg]]").first_node::<Link>().unwrap();
    /// assert!(link.is_image());
    /// ```
    pub fn is_image(&self) -> bool {
        const IMAGE_SUFFIX: &[&str] = &[
            // https://github.com/bzg/org-mode/blob/7de1e818d5fbe6a05c6b1a007eed07dc27e7246b/lisp/ox.el#L253
            ".png", ".jpeg", ".jpg", ".gif", ".tiff", ".tif", ".xbm", ".xpm", ".pbm", ".pgm",
            ".ppm", ".webp", ".avif", ".svg",
        ];

        let path = self.path();

        IMAGE_SUFFIX.iter().any(|e| path.ends_with(e)) && !self.has_description()
    }

    /// Returns caption keyword in this link
    ///
    /// ```rust
    /// use orgize::{Org, ast::Link};
    ///
    /// let link = Org::parse("#+CAPTION: image link\n[[file:/home/dominik/images/jupiter.jpg]]").first_node::<Link>().unwrap();
    /// assert_eq!(link.caption().unwrap().value().unwrap(), " image link");
    /// ```
    pub fn caption(&self) -> Option<AffiliatedKeyword> {
        // TODO: support other element type
        Paragraph::cast(self.syntax.parent()?.clone())?.caption()
    }
}