Simplify down to show-days

src/cache/cache.rs

@@ -3,8 +3,8 @@ use std::io::{BufReader, BufWriter};
 use std::path::{Path, PathBuf};
 
 use super::CacheLine;
-use crate::cli::View;
 use crate::os::Os;
+use crate::View;
 
 #[derive(Debug)]
 pub struct Cache {
@@ -13,7 +13,7 @@ pub struct Cache {
 }
 
 impl Cache {
-    pub fn load(view: View) -> Option<Self> {
+    pub fn load(view: &View) -> Option<Self> {
         let config_opt = Os::get_current()?.get_config_path();
         let mut config_path = match config_opt {
             Ok(k) => k,

src/cli/cli_t.rs

@@ -1,6 +1,6 @@
 use clap::{arg, Parser, ValueEnum};
 
-use crate::ecb_url;
+use super::{ShowDays, SortBy};
 
 #[derive(Debug, Parser)]
 #[command(author, version, about)]
@@ -30,7 +30,7 @@ pub struct Cli {
     pub force_color: bool,
 
     /// Sort by the currency name (in alphabetical order), or by the rate value (low -> high)
-    #[arg(value_enum, long = "sort-by", short = 's', default_value_t = SortBy::Currency)]
+    #[arg(value_enum, long = "sort-by", default_value_t = SortBy::Currency)]
     pub sort_by: SortBy,
 
     /// Recalculate to the perspective from an included currency
@@ -46,51 +46,8 @@ pub struct Cli {
     pub max_decimals: u8,
 
     /// Amount of data
-    #[arg(value_enum, default_value_t = View::TODAY, long="view", short='v')]
-    pub view: View,
-}
-
-#[derive(Debug, Clone, Copy, ValueEnum)]
-pub enum SortBy {
-    Currency,
-    Rate,
-}
-
-#[derive(Debug, Clone, Copy, ValueEnum)]
-pub enum View {
-    #[clap(name = "last-day")]
-    TODAY,
-    #[clap(name = "last-90-days")]
-    HistDays90,
-    #[clap(name = "all-days")]
-    HistDaysAll,
-}
-
-impl View {
-    pub fn to_ecb_url(&self) -> &'static str {
-        match self {
-            View::TODAY => ecb_url::TODAY,
-            View::HistDays90 => ecb_url::hist::DAYS_90,
-            View::HistDaysAll => ecb_url::hist::DAYS_ALL,
-        }
-    }
-
-    pub fn get_name(&self) -> &'static str {
-        match self {
-            View::TODAY => "today",
-            View::HistDays90 => "last-90-days",
-            View::HistDaysAll => "all-days",
-        }
-    }
-}
-
-impl SortBy {
-    pub fn get_comparer(&self) -> fn(&(&str, f64), &(&str, f64)) -> std::cmp::Ordering {
-        match self {
-            Self::Currency => |a, b| a.0.cmp(&b.0),
-            Self::Rate => |a, b| a.1.total_cmp(&b.1),
-        }
-    }
+    #[arg(default_value_t = ShowDays::Days(1), long="show_days", short='s')]
+    pub show_days: ShowDays,
 }
 
 #[derive(Debug, Clone, Copy, ValueEnum)]

src/cli/mod.rs

@@ -0,0 +1,7 @@
+mod cli_t;
+mod since;
+mod sort_by;
+
+pub use cli_t::{Cli, FormatOption};
+pub use since::ShowDays;
+pub use sort_by::SortBy;

src/cli/since.rs

@@ -0,0 +1,54 @@
+use crate::View;
+use std::{fmt, str::FromStr};
+
+#[derive(Debug, Clone, Copy)]
+pub enum ShowDays {
+    Days(usize),
+    All,
+}
+
+impl FromStr for ShowDays {
+    type Err = String;
+
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        if s.eq_ignore_ascii_case("all") {
+            return Ok(ShowDays::All);
+        }
+        s.parse::<usize>().map(ShowDays::Days).map_err(|_| {
+            format!(
+                "Invalid value for since: '{}'. Use a positive integer or 'start'.",
+                s
+            )
+        })
+    }
+}
+impl fmt::Display for ShowDays {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match self {
+            ShowDays::Days(days) => write!(f, "{}", days),
+            ShowDays::All => write!(f, "all"),
+        }
+    }
+}
+
+impl ShowDays {
+    /// None represents infinity
+    pub fn to_option(&self) -> Option<usize> {
+        match self {
+            ShowDays::Days(d) => Some(*d),
+            ShowDays::All => None,
+        }
+    }
+
+    pub fn to_view(&self) -> Option<View> {
+        match self {
+            ShowDays::Days(d) => match d {
+                0 => None,
+                1 => Some(View::TODAY),
+                2..=90 => Some(View::HistDays90),
+                91.. => Some(View::HistDaysAll),
+            },
+            ShowDays::All => Some(View::HistDaysAll),
+        }
+    }
+}

src/cli/sort_by.rs

@@ -0,0 +1,16 @@
+use clap::ValueEnum;
+
+#[derive(Debug, ValueEnum, Clone)]
+pub enum SortBy {
+    Currency,
+    Rate,
+}
+
+impl SortBy {
+    pub fn get_comparer(&self) -> fn(&(&str, f64), &(&str, f64)) -> std::cmp::Ordering {
+        match self {
+            Self::Currency => |a, b| a.0.cmp(&b.0),
+            Self::Rate => |a, b| a.1.total_cmp(&b.1),
+        }
+    }
+}

src/lib.rs

@@ -7,9 +7,11 @@ pub mod os;
 pub mod parsing;
 pub mod table;
 pub mod utils_calc;
+mod view;
 
 pub use header_description::HeaderDescription;
 pub use holiday::Hollidays;
+pub use view::View;
 
 const APP_NAME: &'static str = "ECB-rates";
 const DEFAULT_WIDTH: usize = 20;

src/main.rs

@@ -25,11 +25,14 @@ async fn main() -> ExitCode {
 
     let mut header_description = HeaderDescription::new();
     let use_cache = !cli.no_cache;
-    let mut cache = if use_cache {
-        Cache::load(cli.view)
-    } else {
-        None
+    let view = match cli.show_days.to_view() {
+        Some(v) => v,
+        None => {
+            eprintln!("It doesn't make any sence to fetch 0 days right?");
+            return ExitCode::SUCCESS;
+        }
     };
+    let mut cache = if use_cache { Cache::load(&view) } else { None };
     let cache_ok = cache.as_ref().map_or_else(
         || false,
         |c| c.get_cache_line().map_or_else(|| false, |cl| cl.is_valid()),
@@ -44,7 +47,7 @@ async fn main() -> ExitCode {
             .exchange_rate_results
             .clone()
     } else {
-        let parsed = match get_and_parse(cli.view.to_ecb_url()).await {
+        let parsed = match get_and_parse(view.to_ecb_url()).await {
             Ok(k) => k,
             Err(e) => {
                 eprintln!("Failed to get/parse data from ECB: {}", e);
@@ -102,6 +105,18 @@ async fn main() -> ExitCode {
         filter_currencies(&mut parsed, &currencies);
     }
 
+    parsed.reverse();
+    let parsed = match cli.show_days.to_option() {
+        Some(n) => {
+            if parsed.len() <= n {
+                parsed.as_slice()
+            } else {
+                &parsed[0..n]
+            }
+        }
+        None => parsed.as_slice(),
+    };
+
     let output = match cli.command {
         FormatOption::Json => {
             let mut json_values = parsed

src/view.rs

@@ -0,0 +1,25 @@
+use crate::ecb_url;
+
+pub enum View {
+    TODAY,
+    HistDays90,
+    HistDaysAll,
+}
+
+impl View {
+    pub fn to_ecb_url(&self) -> &'static str {
+        match self {
+            Self::TODAY => ecb_url::TODAY,
+            Self::HistDays90 => ecb_url::hist::DAYS_90,
+            Self::HistDaysAll => ecb_url::hist::DAYS_ALL,
+        }
+    }
+
+    pub fn get_name(&self) -> &'static str {
+        match self {
+            Self::TODAY => "today",
+            Self::HistDays90 => "last-90-days",
+            Self::HistDaysAll => "all-days",
+        }
+    }
+}