1 files changed, 187 insertions, 0 deletions
diff --git a/src/lastfm.rs b/src/lastfm.rs
new file mode 100644
index 0000000..2666e9a
--- /dev/null
+++ b/src/lastfm.rs
@@ -0,0 +1,187 @@
+use crate::util;
+
+use failure::Fail;
+use std::io::{Read, Write};
+
+mod api_types;
+
+const API_ROOT: &str = "https://ws.audioscrobbler.com/2.0/";
+
+pub struct LastFMClient {
+    client: reqwest::Client,
+    api_key: String,
+    user: String,
+}
+
+pub struct Track {
+    pub artist: String,
+    pub album: String,
+    pub name: String,
+    pub timestamp: i64,
+}
+
+pub struct Tracks<'a> {
+    client: &'a LastFMClient,
+    page: Option<u64>,
+    buf: Vec<Track>,
+    from: Option<i64>,
+}
+
+impl<'a> Tracks<'a> {
+    fn new(client: &LastFMClient, from: Option<i64>) -> Tracks {
+        Tracks {
+            client,
+            page: None,
+            buf: vec![],
+            from,
+        }
+    }
+
+    fn get_next_page(&mut self) -> failure::Fallible<()> {
+        if self.page.is_none() {
+            self.page = Some(self.client.get_total_pages(self.from)?);
+        }
+        let page = self.page.unwrap();
+        if page < 1 {
+            return Ok(());
+        }
+
+        let req = self.client.client.get(API_ROOT).query(&[
+            ("method", "user.getrecenttracks"),
+            ("api_key", &self.client.api_key),
+            ("user", &self.client.user),
+            ("format", "json"),
+            ("page", &format!("{}", page)),
+            ("limit", "200"),
+        ]);
+        let req = if let Some(from) = self.from {
+            req.query(&[("from", &format!("{}", from))])
+        } else {
+            req
+        };
+
+        let mut res = req.send()?;
+
+        if res.status().is_success() {
+            let data: api_types::recent_tracks = res.json()?;
+            self.buf = data
+                .recenttracks
+                .track
+                .iter()
+                .filter(|t| t.date.is_some())
+                .map(|t| {
+                    Ok(Track {
+                        artist: t.artist.text.clone(),
+                        album: t.album.text.clone(),
+                        name: t.name.clone(),
+                        timestamp: t.date.as_ref().unwrap().uts.parse()?,
+                    })
+                })
+                .collect::<failure::Fallible<Vec<Track>>>()?;
+            self.page = Some(page - 1);
+            Ok(())
+        } else {
+            Err(failure::err_msg(res.status().as_str().to_string()))
+        }
+    }
+}
+
+impl<'a> Iterator for Tracks<'a> {
+    type Item = Track;
+
+    fn next(&mut self) -> Option<Track> {
+        if self.buf.is_empty() {
+            let result = self.get_next_page();
+            if result.is_err() {
+                return None;
+            }
+        }
+        self.buf.pop()
+    }
+}
+
+impl LastFMClient {
+    pub fn new(user: &str) -> failure::Fallible<LastFMClient> {
+        Ok(LastFMClient {
+            client: reqwest::Client::new(),
+            api_key: find_api_key()?,
+            user: user.to_string(),
+        })
+    }
+
+    pub fn track_count(&self, from: Option<i64>) -> failure::Fallible<u64> {
+        let data = self.recent_tracks(from)?;
+        Ok(data.recenttracks.attr.total.parse()?)
+    }
+
+    pub fn tracks(&self, from: Option<i64>) -> Tracks {
+        Tracks::new(&self, from)
+    }
+
+    fn get_total_pages(&self, from: Option<i64>) -> failure::Fallible<u64> {
+        let data = self.recent_tracks(from)?;
+        Ok(data.recenttracks.attr.totalPages.parse()?)
+    }
+
+    fn recent_tracks(
+        &self,
+        from: Option<i64>,
+    ) -> failure::Fallible<api_types::recent_tracks> {
+        let req = self.client.get(API_ROOT).query(&[
+            ("method", "user.getrecenttracks"),
+            ("api_key", &self.api_key),
+            ("user", &self.user),
+            ("format", "json"),
+            ("limit", "200"),
+        ]);
+        let req = if let Some(from) = from {
+            req.query(&[("from", &format!("{}", from))])
+        } else {
+            req
+        };
+
+        let mut res = req.send()?;
+
+        if res.status().is_success() {
+            let data: api_types::recent_tracks = res.json()?;
+            Ok(data)
+        } else {
+            Err(failure::err_msg(res.status().as_str().to_string()))
+        }
+    }
+}
+
+fn find_api_key() -> failure::Fallible<String> {
+    let api_key_path = util::api_key_path()
+        .map_err(|e| e.context("failed to determine api key path"))?;
+    let api_key = if api_key_path.exists() {
+        let mut api_key = String::new();
+        let mut f = std::fs::File::open(&api_key_path).map_err(|e| {
+            e.context(format!("failed to open {}", api_key_path.display()))
+        })?;
+        f.read_to_string(&mut api_key).map_err(|e| {
+            e.context(format!(
+                "failed to read from {}",
+                api_key_path.display()
+            ))
+        })?;
+        api_key
+    } else {
+        let api_key = rpassword::prompt_password_stderr(&format!(
+            "last.fm api key (will be stored in {}): ",
+            api_key_path.display()
+        ))?;
+        std::fs::create_dir_all(api_key_path.parent().unwrap())?;
+        let mut f = std::fs::File::create(&api_key_path).map_err(|e| {
+            e.context(format!("failed to open {}", api_key_path.display()))
+        })?;
+        f.write_all(api_key.as_bytes()).map_err(|e| {
+            e.context(format!(
+                "failed to write to {}",
+                api_key_path.display()
+            ))
+        })?;
+        api_key
+    };
+    Ok(api_key.trim_end().to_string())
+}