b: add view

b/src/main.rs

@@ -1,4 +1,4 @@
-use b::use_case;
+use b::{use_case, BId};
 use std::{io, path::PathBuf};
 use structopt::{clap::Shell, StructOpt};
 
@@ -36,23 +36,38 @@ enum Subcommand {
         )]
         template: PathBuf,
     },
+    #[structopt(name = "view", about = "Views the b file")]
+    View {
+        #[structopt(long = "data-dir")]
+        data_dir: PathBuf,
+        #[structopt(name = "BID")]
+        id: BId,
+    },
 }
 
-fn main() {
+fn main() -> anyhow::Result<()> {
     let opt = Opt::from_args();
     match opt.subcommand {
         Subcommand::Completion { shell } => {
-            Opt::clap().gen_completions_to("b", shell, &mut io::stdout())
+            Opt::clap().gen_completions_to("b", shell, &mut io::stdout());
+            Ok(())
         }
         Subcommand::List {
             data_dir,
             json,
             query,
             time_zone_offset,
-        } => use_case::list(data_dir, json, query, time_zone_offset, &mut io::stdout()),
+        } => {
+            use_case::list(data_dir, json, query, time_zone_offset, &mut io::stdout());
+            Ok(())
+        }
         Subcommand::New {
             data_file,
             template,
-        } => use_case::new(data_file, template),
+        } => {
+            use_case::new(data_file, template);
+            Ok(())
+        }
+        Subcommand::View { data_dir, id } => use_case::view(data_dir, id, &mut io::stdout()),
     }
 }

b/src/use_case.rs

@@ -1,5 +1,7 @@
 mod list;
 mod new;
+mod view;
 
 pub use list::list;
 pub use new::new;
+pub use view::view;

b/src/use_case/view.rs

@@ -0,0 +1,36 @@
+use crate::brepository::BRepository;
+use crate::{BId, TimeZoneOffset};
+use anyhow::Context;
+use std::{fs, io, path::PathBuf};
+
+pub fn view(data_dir: PathBuf, id: BId, writer: &mut impl io::Write) -> anyhow::Result<()> {
+    let time_zone_offset = TimeZoneOffset::default(); // TODO
+    let repository = BRepository::new(data_dir, time_zone_offset);
+    let meta = repository.find_meta(id)?;
+    let meta = meta.with_context(|| "b not found")?;
+    let content = fs::read_to_string(repository.to_content_path_buf(&meta.id).as_path())?;
+    write!(writer, "{}", content)?;
+    Ok(())
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use std::{fs, str::FromStr};
+    use tempfile::tempdir;
+
+    #[test]
+    fn test() {
+        let dir = tempdir().unwrap();
+        let dir20210203 = dir.path().join("flow").join("2021").join("02").join("03");
+        fs::create_dir_all(dir20210203.as_path()).unwrap();
+        let meta = dir20210203.join("20210203T000000Z.json");
+        fs::write(meta.as_path(), "{}").unwrap();
+        let content = meta.with_extension("md");
+        fs::write(content.as_path(), "Hello, world!").unwrap();
+        let bid = BId::from_str("20210203T000000Z").unwrap();
+        let mut output = vec![];
+        view(dir.path().to_path_buf(), bid, &mut output).unwrap();
+        assert_eq!(output, b"Hello, world!");
+    }
+}