diff --git a/Cargo.toml b/Cargo.toml
index 3662cca..bf5f8cd 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -9,7 +9,9 @@ edition = "2021"
 dirs = "4.0.0"
 rust-ini = "0.18.0"
 thiserror = "1.0.31"
+once_cell = "1.10.0"
 
 [dev-dependencies]
 speculoos = "0.9.0"
-anyhow = "1.0.57"
\ No newline at end of file
+anyhow = "1.0.57"
+linicon = "2.3.0"
\ No newline at end of file
diff --git a/src/lib.rs b/src/lib.rs
index a0b887f..daa32e8 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1 +1,54 @@
-pub mod theme;
\ No newline at end of file
+use crate::theme::{try_build_icon_path, FALL_BACK_THEMES, THEMES};
+use std::path::PathBuf;
+
+pub mod theme;
+
+pub fn lookup(name: &str, size: u16, scale: u16, theme: &str) -> Option<PathBuf> {
+    if let Some(theme) = THEMES.get(theme) {
+        let icon = theme.try_get_icon(name, size, scale);
+        if icon.is_some() {
+            return icon;
+        }
+    }
+
+    for theme in FALL_BACK_THEMES.iter() {
+        let icon = theme.try_get_icon(name, size, scale);
+        if icon.is_some() {
+            return icon;
+        }
+    }
+
+    try_build_icon_path(name, "/usr/share/pixmaps")
+}
+
+#[cfg(test)]
+mod test {
+    use crate::lookup;
+    use speculoos::prelude::*;
+
+    #[test]
+    fn compare_to_linincon() {
+        let lin_wireshark = linicon::lookup_icon("wireshark")
+            .next()
+            .unwrap()
+            .unwrap()
+            .path;
+
+        let wireshark = lookup("wireshark", 16, 1, "Papirus");
+
+        assert_that!(wireshark).is_some().is_equal_to(lin_wireshark)
+    }
+
+    #[test]
+    fn compare_to_linicon_in_pixmap() {
+        let archlinux_logo = linicon::lookup_icon("archlinux-logo").next();
+
+        assert_that!(archlinux_logo).is_some();
+
+        let archlinux_logo = lookup("archlinux-logo", 16, 1, "Papirus");
+
+        assert_that!(archlinux_logo)
+            .is_some()
+            .has_file_name("/usr/share/pixmaps/archlinux-logo.png");
+    }
+}
diff --git a/src/theme/directories.rs b/src/theme/directories.rs
new file mode 100644
index 0000000..61a3ae9
--- /dev/null
+++ b/src/theme/directories.rs
@@ -0,0 +1,84 @@
+#[derive(Debug)]
+pub struct Directory<'a> {
+    pub name: &'a str,
+    pub size: i16,
+    pub scale: i16,
+    pub context: Option<&'a str>,
+    pub type_: DirectoryType,
+    pub maxsize: i16,
+    pub minsize: i16,
+    pub threshold: i16,
+}
+
+impl Directory<'_> {
+    pub fn match_size(&self, size: u16, scale: u16) -> bool {
+        let scale = scale as i16;
+        let size = size as i16;
+
+        if self.scale != scale {
+            false
+        } else {
+            match self.type_ {
+                DirectoryType::Fixed => self.size == size,
+                DirectoryType::Scalable => self.minsize <= size && size <= self.maxsize,
+                DirectoryType::Threshold => {
+                    self.size - self.threshold <= size && size <= self.size + self.threshold
+                }
+            }
+        }
+    }
+
+    pub fn directory_size_distance(&self, size: u16, scale: u16) -> i16 {
+        let scaled_size = self.size * self.scale;
+        let min_scaled_size = self.minsize * self.scale;
+        let max_scaled_size = self.maxsize * self.scale;
+        let scale = scale as i16;
+        let size = size as i16;
+        let scaled_requested_size = size * scale;
+
+        match self.type_ {
+            DirectoryType::Fixed => scaled_size - scaled_requested_size,
+            DirectoryType::Scalable => {
+                if scaled_requested_size < min_scaled_size {
+                    min_scaled_size - scaled_requested_size
+                } else if scaled_requested_size < max_scaled_size {
+                    scaled_requested_size - max_scaled_size
+                } else {
+                    0
+                }
+            }
+            DirectoryType::Threshold => {
+                if scaled_requested_size < (self.size - self.threshold) * scale {
+                    min_scaled_size - scaled_requested_size
+                } else if scaled_requested_size > (self.size + self.threshold) * scale {
+                    scaled_requested_size - max_scaled_size
+                } else {
+                    0
+                }
+            }
+        }
+    }
+}
+
+#[derive(Debug)]
+pub enum DirectoryType {
+    Fixed,
+    Scalable,
+    Threshold,
+}
+
+impl Default for DirectoryType {
+    fn default() -> Self {
+        Self::Threshold
+    }
+}
+
+impl From<&str> for DirectoryType {
+    fn from(value: &str) -> Self {
+        match value {
+            "Fixed" => DirectoryType::Fixed,
+            "Scalable" => DirectoryType::Scalable,
+            _ => DirectoryType::Threshold,
+        }
+    }
+}
diff --git a/src/theme/mod.rs b/src/theme/mod.rs
index a616fd8..895356f 100644
--- a/src/theme/mod.rs
+++ b/src/theme/mod.rs
@@ -1,123 +1,172 @@
 use crate::theme::error::ThemeError;
-use dirs::{data_dir, home_dir};
+use crate::theme::paths::{ThemePath, FALLBACK_PATHS};
 use ini::Ini;
-use std::borrow::Cow;
+use once_cell::sync::Lazy;
+use paths::BASE_PATHS;
+use std::collections::BTreeMap;
 use std::fmt::{Debug, Formatter};
-use std::io;
-use std::path::PathBuf;
+use std::path::{Path, PathBuf};
 
+pub mod directories;
 pub mod error;
+pub mod parse;
+pub mod paths;
 
-type Result<T> = std::result::Result<T, error::ThemeError>;
+type Result<T> = std::result::Result<T, ThemeError>;
 
-const HICOLOR: &str = "/usr/share/pixmaps";
+pub static THEMES: Lazy<BTreeMap<String, Theme>> =
+    Lazy::new(|| get_all_themes().expect("Failed to get theme paths"));
 
-#[derive(Debug)]
-struct ThemePath(PathBuf);
+pub static FALL_BACK_THEMES: Lazy<Vec<Theme>> =
+    Lazy::new(|| fallback_themes().expect("Failed to get theme paths"));
 
-struct ThemeIndex(Ini);
+pub struct Theme {
+    path: ThemePath,
+    index: Ini,
+}
 
-impl Debug for ThemeIndex {
-    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
-        let mut content = vec![];
-        self.0.write_to(&mut content).expect("Write error");
-        let content = String::from_utf8_lossy(&content);
-        writeln!(f, "ThemeIndex({content:?})")
+impl Theme {
+    pub fn try_get_icon(&self, name: &str, size: u16, scale: u16) -> Option<PathBuf> {
+        self.try_get_icon_exact_size(name, size, scale)
+            .or(self.try_get_icon_closest_size(name, size, scale))
+    }
+
+    fn try_get_icon_exact_size(&self, name: &str, size: u16, scale: u16) -> Option<PathBuf> {
+        self.match_size(size, scale)
+            .iter()
+            .find_map(|path| try_build_icon_path(name, path))
+    }
+
+    fn match_size(&self, size: u16, scale: u16) -> Vec<PathBuf> {
+        let dirs = self.get_all_directories();
+
+        dirs.iter()
+            .filter(|directory| directory.match_size(size, scale))
+            .map(|dir| dir.name)
+            .map(|dir| self.path().join(dir))
+            .collect()
+    }
+
+    fn try_get_icon_closest_size(&self, name: &str, size: u16, scale: u16) -> Option<PathBuf> {
+        self.closest_match_size(size, scale)
+            .iter()
+            .find_map(|path| try_build_icon_path(name, path))
+    }
+
+    fn closest_match_size(&self, size: u16, scale: u16) -> Vec<PathBuf> {
+        let dirs = self.get_all_directories();
+
+        dirs.iter()
+            .filter(|directory| directory.directory_size_distance(size, scale) < i16::MAX)
+            .map(|dir| dir.name)
+            .map(|dir| self.path().join(dir))
+            .collect()
+    }
+
+    fn path(&self) -> &PathBuf {
+        &self.path.0
     }
 }
 
-impl ThemePath {
-    fn name(&self) -> Cow<'_, str> {
-        // Unwrapping is safe here, we just got the path from [`list_icon_themes`]
-        self.0.file_name().unwrap().to_string_lossy()
+pub(super) fn try_build_icon_path<P: AsRef<Path>>(name: &str, path: P) -> Option<PathBuf> {
+    let path = path.as_ref();
+    let png = path.join(format!("{name}.png"));
+    if png.exists() {
+        return Some(png);
     }
 
-    fn index(&self) -> Result<ThemeIndex> {
-        let index = self.0.join("index.theme");
-
-        if !index.exists() {
-            return Err(ThemeError::ThemeIndexNotFound(index));
-        }
-
-        let index = Ini::load_from_file(index)?;
-
-        Ok(ThemeIndex(index))
+    let svg = path.join(format!("{name}.svg"));
+    if svg.exists() {
+        return Some(svg);
     }
-}
-/// Look in $HOME/.icons (for backwards compatibility), in $XDG_DATA_DIRS/icons and in /usr/share/pixmaps (in that order).
-/// Paths that are not found are filtered out.
-fn icon_theme_base_paths() -> Vec<PathBuf> {
-    let home_icon_dir = home_dir().expect("No $HOME directory").join(".icons");
-    let usr_data_dir = data_dir().expect("No $XDG_DATA_DIR").join("icons");
-    let xdg_data_dirs_local = PathBuf::from("/usr/local/share/").join("icons");
-    let xdg_data_dirs = PathBuf::from("/usr/share/").join("icons");
+    let xmp = path.join(format!("{name}.xmp"));
 
-    [
-        home_icon_dir,
-        usr_data_dir,
-        xdg_data_dirs_local,
-        xdg_data_dirs,
-    ]
-    .into_iter()
-    .filter(|p| p.exists())
-    .collect()
+    if xmp.exists() {
+        return Some(xmp);
+    }
+
+    None
 }
 
 // Iter through the base paths and get all theme directories
-fn list_icon_themes() -> io::Result<Vec<ThemePath>> {
-    let mut icon_theme_path = vec![];
-    for theme_base_dir in icon_theme_base_paths().iter() {
+fn get_all_themes() -> Result<BTreeMap<String, Theme>> {
+    let mut icon_themes = BTreeMap::new();
+    for theme_base_dir in BASE_PATHS.iter() {
         for entry in theme_base_dir.read_dir()? {
             let entry = entry?;
-            let has_index = entry.path().join("index.theme").exists();
-            if entry.path().is_dir() && has_index {
-                icon_theme_path.push(ThemePath(entry.path()));
+            if let Some(theme) = Theme::from_path(entry.path()) {
+                let name = entry.file_name().to_string_lossy().to_string();
+                icon_themes.insert(name, theme);
             }
         }
     }
-    Ok(icon_theme_path)
+    Ok(icon_themes)
+}
+
+fn fallback_themes() -> Result<Vec<Theme>> {
+    let mut icon_themes = vec![];
+    for theme_base_dir in FALLBACK_PATHS.iter() {
+        for entry in theme_base_dir.read_dir()? {
+            let entry = entry?;
+            if let Some(theme) = Theme::from_path(entry.path()) {
+                icon_themes.push(theme);
+            }
+        }
+    }
+
+    Ok(icon_themes)
+}
+
+pub fn theme_names() -> Vec<&'static str> {
+    THEMES
+        .values()
+        .map(|path| &path.index)
+        .filter_map(|index| {
+            index
+                .section(Some("Icon Theme"))
+                .and_then(|section| section.get("Name").map(|s| s))
+        })
+        .collect()
+}
+
+impl Theme {
+    fn from_path<P: AsRef<Path>>(path: P) -> Option<Self> {
+        let path = path.as_ref();
+
+        let has_index = path.join("index.theme").exists();
+
+        if !has_index || !path.is_dir() {
+            return None;
+        }
+
+        let path = ThemePath(path.into());
+
+        match path.index() {
+            Ok(index) => Some(Theme { path, index }),
+            Err(_) => None,
+        }
+    }
+}
+
+impl Debug for Theme {
+    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
+        let mut content = vec![];
+        self.index.write_to(&mut content).expect("Write error");
+        let content = String::from_utf8_lossy(&content);
+        writeln!(f, "ThemeIndex{{path: {:?}, index: {content:?}}}", self.path)
+    }
 }
 
 #[cfg(test)]
 mod test {
-    use crate::theme::{icon_theme_base_paths, list_icon_themes};
-    use anyhow::Result;
-    use speculoos::prelude::*;
+    use crate::THEMES;
 
     #[test]
-    fn should_get_theme_paths_ordered() {
-        let base_paths = icon_theme_base_paths();
-
-        assert_that!(base_paths).is_not_empty()
-    }
-
-    #[test]
-    fn should_get_icon_theme_paths_ordered() -> Result<()> {
-        let themes = list_icon_themes()?;
-
-        assert_that!(themes).is_not_empty();
-        Ok(())
-    }
-
-    #[test]
-    fn should_read_theme_index() -> Result<()> {
-        let paths = list_icon_themes()?;
-
-        for theme_path in paths {
-            assert_that!(theme_path.index()).is_ok();
-        }
-
-        Ok(())
-    }
-
-    #[test]
-    fn should_get_theme_name() -> Result<()> {
-        let paths = list_icon_themes()?;
-
-        for theme_path in paths {
-            assert_that!(theme_path.name().len()).is_greater_than(0);
-        }
-
-        Ok(())
+    fn get_one_icon() {
+        let theme = THEMES.get("Adwaita").unwrap();
+        println!(
+            "{:?}",
+            theme.try_get_icon_exact_size("edit-delete-symbolic", 24, 1)
+        );
     }
 }
diff --git a/src/theme/parse.rs b/src/theme/parse.rs
new file mode 100644
index 0000000..1fcd014
--- /dev/null
+++ b/src/theme/parse.rs
@@ -0,0 +1,74 @@
+use crate::theme::directories::{Directory, DirectoryType};
+use crate::theme::Theme;
+use ini::Properties;
+
+impl Theme {
+    pub(super) fn get_all_directories(&self) -> Vec<Directory> {
+        let dir_names = self.directories().unwrap_or(vec![]);
+        let mut dirs = vec![];
+        for dir in dir_names {
+            let dir = self.get_directory(dir);
+            if let Some(dir) = dir {
+                dirs.push(dir);
+            }
+        }
+
+        dirs
+    }
+
+    fn scaled_directories(&self) -> Option<Vec<&str>> {
+        self.get_icon_theme_section()
+            .and_then(|props| props.get("ScaledDirectories"))
+            .map(|dirs| dirs.split(',').collect())
+    }
+
+    fn get_icon_theme_section(&self) -> Option<&Properties> {
+        self.index.section(Some("Icon Theme"))
+    }
+
+    pub fn inherits(&self) -> Option<&str> {
+        self.get_icon_theme_section()
+            .and_then(|props| props.get("Inherits"))
+    }
+
+    fn directories(&self) -> Option<Vec<&str>> {
+        self.index
+            .section(Some("Icon Theme"))
+            .and_then(|props| props.get("Directories"))
+            .map(|dirs| dirs.split(',').collect())
+    }
+
+    fn get_directory<'a>(&'a self, name: &'a str) -> Option<Directory> {
+        self.index.section(Some(name)).map(|props| {
+            let size = props
+                .get("Size")
+                .and_then(|size| str::parse(size).ok())
+                .expect("Size not found for icon");
+            Directory {
+                name,
+                size,
+                scale: props
+                    .get("Scale")
+                    .and_then(|scale| str::parse(scale).ok())
+                    .unwrap_or(1),
+                context: props.get("Context"),
+                type_: props
+                    .get("Type")
+                    .map(DirectoryType::from)
+                    .unwrap_or_default(),
+                maxsize: props
+                    .get("MaxSize")
+                    .and_then(|max| str::parse(max).ok())
+                    .unwrap_or(size),
+                minsize: props
+                    .get("MinSize")
+                    .and_then(|min| str::parse(min).ok())
+                    .unwrap_or(size),
+                threshold: props
+                    .get("Threshold")
+                    .and_then(|thrsh| str::parse(thrsh).ok())
+                    .unwrap_or(2),
+            }
+        })
+    }
+}
diff --git a/src/theme/paths.rs b/src/theme/paths.rs
new file mode 100644
index 0000000..266a5c9
--- /dev/null
+++ b/src/theme/paths.rs
@@ -0,0 +1,72 @@
+use crate::theme;
+use crate::theme::error::ThemeError;
+use dirs::{data_dir, home_dir};
+use ini::Ini;
+use once_cell::sync::Lazy;
+use std::path::PathBuf;
+
+pub(crate) static BASE_PATHS: Lazy<Vec<PathBuf>> = Lazy::new(|| icon_theme_base_paths());
+pub(crate) static FALLBACK_PATHS: Lazy<Vec<PathBuf>> = Lazy::new(|| {
+    vec![
+        data_dir()
+            .expect("Failed to get DATA_DIR")
+            .join("icons/hicolor"),
+        PathBuf::from("usr/share/icons/hicolor"),
+    ]
+});
+
+/// Look in $HOME/.icons (for backwards compatibility), in $XDG_DATA_DIRS/icons and in /usr/share/pixmaps (in that order).
+/// Paths that are not found are filtered out.
+fn icon_theme_base_paths() -> Vec<PathBuf> {
+    let home_icon_dir = home_dir().expect("No $HOME directory").join(".icons");
+    let usr_data_dir = data_dir().expect("No $XDG_DATA_DIR").join("icons");
+    let xdg_data_dirs_local = PathBuf::from("/usr/local/share/").join("icons");
+    let xdg_data_dirs = PathBuf::from("/usr/share/").join("icons");
+
+    [
+        home_icon_dir,
+        usr_data_dir,
+        xdg_data_dirs_local,
+        xdg_data_dirs,
+    ]
+    .into_iter()
+    .filter(|p| p.exists())
+    .collect()
+}
+
+#[derive(Debug)]
+pub struct ThemePath(pub PathBuf);
+
+impl ThemePath {
+    pub(super) fn index(&self) -> theme::Result<Ini> {
+        let index = self.0.join("index.theme");
+
+        if !index.exists() {
+            return Err(ThemeError::ThemeIndexNotFound(index));
+        }
+
+        Ok(Ini::load_from_file(index)?)
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use crate::theme::paths::icon_theme_base_paths;
+    use crate::theme::{get_all_themes, Theme};
+    use anyhow::Result;
+    use speculoos::prelude::*;
+
+    #[test]
+    fn should_get_theme_paths_ordered() {
+        let base_paths = icon_theme_base_paths();
+        assert_that!(base_paths).is_not_empty()
+    }
+
+    #[test]
+    fn should_read_theme_index() -> Result<()> {
+        let themes = get_all_themes()?;
+        let themes: Vec<&Theme> = themes.values().collect();
+        assert_that!(themes).is_not_empty();
+        Ok(())
+    }
+}