WIP: encoder

app/src/app.rs

@@ -26,7 +26,7 @@ impl Application {
 
         debug!("Bootstrapping application...");
 
-        let container = Container::new(&config).await?;
+        let container = Container::new().await?;
 
         Ok(Self {
             config,
@@ -43,12 +43,17 @@ impl Application {
             Command::Decode(_) => {
                 commands::decode::run(self.config.decoder).await;
             }
+            Command::Encode(_) => {
+                let repo = self.container.create_dict_repo("demo_pl").await?;
+
+                commands::encode::run(self.config.encoder, repo.as_ref()).await;
+            }
             Command::ImportDict(_) => {
-                commands::import_dict::run(
-                    self.config.import_dict,
-                    self.container.dict_repository.clone(),
-                )
-                .await?;
+                let importer = self
+                    .container
+                    .create_dict_importer(&self.config.import_dict.name)
+                    .await?;
+                commands::import_dict::run(self.config.import_dict, importer).await?;
             }
         }
         Ok(())

app/src/config.rs

@@ -3,12 +3,13 @@ use config::{Config, Environment, File};
 use serde::Deserialize;
 
 use applib::cli::{Command, GlobalArgs, defaults::set_defaults};
-use applib::config::{DecoderConfig, ImportDictConfig, ServerConfig};
+use applib::config::*;
 
 #[derive(Debug, Deserialize, Clone)]
 pub struct AppConfig {
     pub server: ServerConfig,
     pub decoder: DecoderConfig,
+    pub encoder: EncoderConfig,
     pub import_dict: ImportDictConfig,
     pub log_level: String,
 }
@@ -46,6 +47,12 @@ impl AppConfig {
                 }
                 builder = builder.set_override("decoder.input", cmd_args.input.clone())?;
             }
+            Command::Encode(cmd_args) => {
+                if let Some(name) = &cmd_args.system {
+                    builder = builder.set_override("encoder.system", name.as_str())?;
+                }
+                builder = builder.set_override("encoder.input", cmd_args.input.clone())?;
+            }
             Command::ImportDict(cmd_args) => {
                 builder = builder.set_override("import_dict.name", cmd_args.name.clone())?;
                 builder = builder.set_override("import_dict.path", cmd_args.path.clone())?;

app/src/container.rs

@@ -1,20 +1,29 @@
-use crate::config::AppConfig;
-use applib::application::services::DictImporter;
+use std::sync::Arc;
+
+// use crate::config::AppConfig;
+use applib::DictImporter;
 use applib::infrastructure::sqlite_dict_repository::SqliteDictRepository;
+use applib::traits::DictRepository;
 
 #[derive(Clone)]
-pub struct Container {
-    pub dict_repository: SqliteDictRepository,
-}
+pub struct Container;
 
 impl Container {
-    pub async fn new(config: &AppConfig) -> anyhow::Result<Self> {
-        let dict_repository = SqliteDictRepository::new("sqlite:app.db").await?;
+    pub async fn new() -> anyhow::Result<Self> {
+        Ok(Self)
+    }
 
-        Ok(Self { dict_repository })
+    pub async fn create_dict_importer(&self, dict_name: &str) -> anyhow::Result<DictImporter> {
+        let repo = self.create_dict_repo(dict_name).await?;
+        Ok(DictImporter::new(repo))
     }
 
-    pub fn create_dict_importer(&self) -> DictImporter<SqliteDictRepository> {
-        DictImporter::new(&self.dict_repository)
+    pub async fn create_dict_repo(
+        &self,
+        dict_name: &str,
+    ) -> anyhow::Result<Arc<dyn DictRepository>> {
+        let mut dict_repo = SqliteDictRepository::new("sqlite:app.db").await?;
+        dict_repo.use_dict(dict_name);
+        Ok(Arc::new(dict_repo))
     }
 }

lib/Cargo.toml

@@ -18,6 +18,7 @@ thiserror = "2.0"
 async-trait = "0.1"
 parking_lot = "0.12"
 sqlx = { version = "0.8.6", features = ["runtime-tokio", "sqlite", "chrono", "migrate"] }
+futures = "0.3.31"
 
 [dev-dependencies]
 mockall = "0.14.0"

lib/src/application/config.rs

@@ -12,6 +12,12 @@ pub struct DecoderConfig {
     pub input: String,
 }
 
+#[derive(Debug, Deserialize, Clone)]
+pub struct EncoderConfig {
+    pub system: System,
+    pub input: String,
+}
+
 #[derive(Debug, Deserialize, Clone)]
 pub struct ImportDictConfig {
     pub name: String,

lib/src/application/services.rs

@@ -1,18 +1,25 @@
+use std::sync::Arc;
+
 use crate::core::traits::{DictRepository, DictSource};
 
-pub struct DictImporter<'a, R> {
-    repo: &'a R,
+pub struct DictImporter {
+    repo: Arc<dyn DictRepository>,
     batch_size: usize,
 }
 
-impl<'a, R: DictRepository> DictImporter<'a, R> {
-    pub fn new(repo: &'a R) -> Self {
+impl DictImporter {
+    pub fn new(repo: Arc<dyn DictRepository>) -> Self {
         Self {
             repo,
             batch_size: 1000, // reasonable default
         }
     }
 
+    pub fn with_batch_size(mut self, batch_size: usize) -> Self {
+        self.batch_size = batch_size;
+        self
+    }
+
     pub async fn import(&self, mut source: impl DictSource) -> Result<(), anyhow::Error> {
         // 1. Ensure Dict exists (Logic: Create if new, or maybe clear existing?)
         self.repo.create_dict().await?;

lib/src/core/entities.rs

@@ -5,16 +5,26 @@ use std::{collections::HashMap, u64};
 
 /// A number encoded as a sequence of words
 #[derive(Debug, Clone)]
-pub struct EncodedValue(Vec<String>);
+pub struct EncodedPart {
+    pub value: u64,
+    pub words: Vec<String>,
+}
+
+/// A way (variant) to split input number
+pub type EncodedSplit = Vec<EncodedPart>;
+
+/// A number encoded as words, split in multiple ways
+#[derive(Debug, Clone)]
+pub struct EncodedValue(Vec<EncodedSplit>);
 
 impl EncodedValue {
-    pub fn new(data: Vec<String>) -> Self {
+    pub fn new(data: Vec<EncodedSplit>) -> Self {
         EncodedValue(data)
     }
 }
 
 impl Deref for EncodedValue {
-    type Target = Vec<String>;
+    type Target = Vec<EncodedSplit>;
 
     fn deref(&self) -> &Self::Target {
         &self.0

lib/src/core/sys_major/encoder.rs

@@ -1,4 +1,11 @@
-use crate::core::{entities::EncodedValue, errors::CodecError, sys_major::LenValueMap, traits::*};
+use core::num;
+
+use crate::core::{
+    entities::{EncodedPart, EncodedSplit, EncodedValue},
+    errors::CodecError,
+    sys_major::LenValueMap,
+    traits::*,
+};
 
 #[derive(Debug)]
 pub struct Encoder {
@@ -15,69 +22,95 @@ impl SystemEncoder for Encoder {
     fn initialize(&self) -> Result<(), CodecError> {
         Ok(())
     }
-    fn encode(&self, word: &str) -> Result<EncodedValue, CodecError> {
-        let size = word.chars().count();
+
+    fn encode(&self, input: &str) -> Result<EncodedValue, CodecError> {
+        let size = input.chars().count();
         let max_mask: usize = (1 << (size - 1)) - 1;
 
-        let indices: Vec<usize> = word.char_indices().map(|(i, _)| i).collect();
+        let indices: Vec<usize> = input.char_indices().map(|(i, _)| i).collect();
         let mut results = Vec::with_capacity(max_mask);
 
         for mask in 0..=max_mask {
-            let mut parts = Vec::new();
-            let mut last_split = 0;
+            let mut parts: Vec<String> = Vec::new();
+            let mut last_split = input.char_indices().count(); // we go from right to left to start with the longest parts
 
             // Iterate through the mask bits to find where to split
             for i in 0..size - 1 {
                 // Check if the i-th bit is set
                 if (mask >> i) & 1 == 1 {
                     // The split corresponds to the byte index of the (i+1)-th character
-                    let split_idx = indices[i + 1];
-                    parts.push(&word[last_split..split_idx]);
+                    let split_idx = indices[indices.len() - i - 1];
+                    parts.push(input[split_idx..last_split].to_string());
                     last_split = split_idx;
                 }
             }
             // Push the remaining part of the string
-            parts.push(&word[last_split..]);
-
-            // Calculate metrics for sorting
-            let num_parts = parts.len();
-
-            // To find the "most equal" size, we minimize the sum of squared lengths.
-            // (This mathematically minimizes variance without needing floating point math)
-            let sum_sq_len: usize = parts.iter().map(|p| p.chars().count().pow(2)).sum();
+            parts.push(input[..last_split].to_string());
+
+            let mut all_matched = true;
+            let mut split = EncodedSplit::new();
+            parts.reverse();
+
+            for part in &parts {
+                let Ok(num_part) = part.parse::<u64>() else {
+                    all_matched = false;
+                    break;
+                };
+                let Some(words) = self.lv_map.get(part.len() as u8, num_part) else {
+                    all_matched = false;
+                    break;
+                };
+                split.push(EncodedPart {
+                    value: num_part,
+                    words: words.clone(),
+                });
+            }
 
-            // Construct the final string representation (e.g., "abc|de|fg")
-            let result_string = parts.join("|");
+            if all_matched {
+                results.push(Partition {
+                    value: split,
+                    // To find the "most equal" size, we minimize the sum of squared lengths.
+                    // (This mathematically minimizes variance without needing floating point math)
+                    sum_sq_len: parts.iter().map(|p| p.chars().count().pow(2)).sum(),
+                });
+            }
 
-            results.push(Partition {
-                word: result_string,
-                num_parts,
-                sum_sq_len,
-            });
+            // Calculate metrics for sorting
+            // let num_parts = parts.len();
+
+            // // To find the "most equal" size, we minimize the sum of squared lengths.
+            // // (This mathematically minimizes variance without needing floating point math)
+            // let sum_sq_len: usize = parts.iter().map(|p| p.chars().count().pow(2)).sum();
+
+            // if let Some(words) = self.lv_map.get(size as u8, input.parse().unwrap()) {
+            //     results.push(Partition {
+            //         parts: words.clone(),
+            //         sum_sq_len,
+            //     });
+            // }
         }
 
         // Ok(EncodedValue::new(words))
         // Sort by:
         // 1. Fewer parts first (1 part, then 2 parts...)
         // 2. Most equal lengths (lower sum of squared lengths is more balanced)
-        // 3. Lexicographically (for deterministic stability)
+        // 3. TODO: Lexicographically (for deterministic stability)?
         results.sort_by(|a, b| {
-            a.num_parts
-                .cmp(&b.num_parts)
+            a.value
+                .len()
+                .cmp(&b.value.len())
                 .then(a.sum_sq_len.cmp(&b.sum_sq_len))
-                .then(a.word.cmp(&b.word))
         });
 
         // Extract just the strings
-        let words = results.into_iter().map(|p| p.word).collect();
-        Ok(EncodedValue::new(words))
+        let split_results = results.into_iter().map(|p| p.value).collect();
+        Ok(EncodedValue::new(split_results))
     }
 }
 
-// A helper struct to keep the string and its sort metrics together
+// A helper struct to keep the split variant and its sort metrics together
 struct Partition {
-    word: String,
-    num_parts: usize,
+    value: EncodedSplit,
     sum_sq_len: usize,
 }
 
@@ -95,9 +128,12 @@ mod tests {
         let encoder = Encoder::new(lvmap);
         let result = encoder.encode("345").unwrap();
 
-        assert_eq!(result.len(), 2);
-        assert!(result.contains(&"test_345_1".into()));
-        assert!(result.contains(&"test_345_2".into()));
+        assert_eq!(result.len(), 1); // single split
+        assert_eq!(result[0].len(), 1); // single part
+        assert_eq!(result[0][0].value, 345);
+        assert_eq!(result[0][0].words.len(), 2); // two words
+        assert_eq!(result[0][0].words[0], "test_345_1");
+        assert_eq!(result[0][0].words[1], "test_345_2");
     }
 
     #[test]
@@ -106,6 +142,7 @@ mod tests {
         lvmap.push(1, 0, "test_0");
         lvmap.push(1, 9, "test_9");
         lvmap.push(1, 8, "test_8");
+        lvmap.push(1, 7, "test_7");
         lvmap.push(2, 98, "test_98");
         lvmap.push(2, 87, "test_87");
         lvmap.push(3, 987, "test_987");
@@ -114,11 +151,30 @@ mod tests {
         let encoder = Encoder::new(lvmap);
         let result = encoder.encode("987").unwrap();
 
-        assert_eq!(result.len(), 5);
-        assert!(result.contains(&"test_987".into()));
-        assert!(result.contains(&"test_98".into()));
-        assert!(result.contains(&"test_87".into()));
-        assert!(result.contains(&"test_9".into()));
-        assert!(result.contains(&"test_8".into()));
+        assert_eq!(result.len(), 4); // 987, 98|7, 9|87, 9|8|7
+        assert_eq!(result[0].len(), 1); // 987
+
+        assert_eq!(result[0][0].words.len(), 1);
+        assert_eq!(result[0][0].words[0], "test_987");
+
+        assert_eq!(result[1].len(), 2); // 98|7
+        assert_eq!(result[1][0].words.len(), 1);
+        assert_eq!(result[1][0].words[0], "test_98");
+        assert_eq!(result[1][1].words.len(), 1);
+        assert_eq!(result[1][1].words[0], "test_7");
+
+        assert_eq!(result[2].len(), 2); // 9|87
+        assert_eq!(result[2][0].words.len(), 1);
+        assert_eq!(result[2][0].words[0], "test_9");
+        assert_eq!(result[2][1].words.len(), 1);
+        assert_eq!(result[2][1].words[0], "test_87");
+
+        assert_eq!(result[3].len(), 3); // 9|8|7
+        assert_eq!(result[3][0].words.len(), 1);
+        assert_eq!(result[3][0].words[0], "test_9");
+        assert_eq!(result[3][1].words.len(), 1);
+        assert_eq!(result[3][1].words[0], "test_8");
+        assert_eq!(result[3][2].words.len(), 1);
+        assert_eq!(result[3][2].words[0], "test_7");
     }
 }

lib/src/core/sys_major/lvmap.rs

@@ -1,4 +1,9 @@
-use crate::core::{DictRepository, SystemDecoder, entities::DecodedLength, errors::CodecError};
+use crate::core::{
+    DictRepository, SystemDecoder,
+    entities::DecodedLength,
+    errors::{CodecError, RepositoryError},
+};
+use futures::{Stream, StreamExt, TryStreamExt};
 use std::{collections::HashMap, hash::Hash, num::ParseIntError};
 use thiserror::Error;
 
@@ -26,6 +31,9 @@ pub enum LenValueMapError {
     #[error(transparent)]
     Codec(#[from] CodecError),
 
+    #[error(transparent)]
+    Repository(#[from] RepositoryError),
+
     #[error("unable to build encoder data: {0}")]
     Build(String),
 }
@@ -61,6 +69,10 @@ impl LenValueMap {
         self
     }
 
+    pub fn get(&self, len: u8, num: DecodedNumber) -> Option<&Vec<String>> {
+        self.data.get(&DecodedLength::from(len))?.get(&num)
+    }
+
     pub fn insert_words<I>(
         &mut self,
         words: I,
@@ -89,38 +101,28 @@ impl LenValueMap {
         Self { data: data }
     }
 
-    pub async fn from_dict(
-        decoder: &impl SystemDecoder,
-        repo: &impl DictRepository,
-    ) -> Result<Self, LenValueMapError> {
-        Self::build(decoder, repo, DEFAULT_DICT_BATCH_SIZE).await
-    }
-
-    async fn build(
-        decoder: &impl SystemDecoder,
-        repo: &impl DictRepository,
-        batch_size: usize,
-    ) -> Result<Self, LenValueMapError> {
+    pub async fn from_stream<S>(
+        mut stream: S,
+        decoder: &dyn SystemDecoder,
+    ) -> Result<Self, LenValueMapError>
+    where
+        // S is a stream of "Result<Vec<String>, Error>"
+        S: Stream<Item = Result<Vec<String>, crate::core::errors::RepositoryError>> + Unpin,
+    {
         let mut map = LenValueMap::new();
-        let mut offset = 0;
-        const MAX_OFFSET: usize = 10_000_000;
-
-        loop {
-            let dict = repo
-                .fetch_many(batch_size, offset)
-                .await
-                .map_err(|e| LenValueMapError::Build(e.to_string()))?;
-
-            if dict.entries.is_empty() {
-                break;
-            }
 
-            let words: Vec<String> = dict.entries.into_iter().map(|entry| entry.1.text).collect();
-            map.insert_words(words, decoder)?;
-
-            offset += batch_size;
-            if offset >= MAX_OFFSET {
-                break;
+        // We stream the batches one by one.
+        // This ensures only one batch is in memory at a time.
+        while let Some(batch_result) = stream.next().await {
+            match batch_result {
+                Ok(batch) => {
+                    // We delegate to the synchronous logic for the heavy lifting
+                    map.insert_words(batch, decoder)?;
+                }
+                Err(e) => {
+                    // Convert RepositoryError to LenValueMapError::Build
+                    return Err(e.into());
+                }
             }
         }
 
@@ -133,6 +135,8 @@ mod tests {
     use super::*;
     use crate::core::{entities::*, errors::*};
     use async_trait::async_trait;
+    use futures::stream;
+
     use std::collections::HashMap;
 
     use mockall::{Sequence, automock};
@@ -260,22 +264,6 @@ mod tests {
 
     // --- build ---
 
-    mock! {
-        pub Repo {}
-
-        #[async_trait]
-        impl DictRepository for Repo {
-            async fn create_dict(&self) -> Result<(), RepositoryError>;
-            fn use_dict(&mut self, _name: &str);
-            async fn save_entries(&self, _entry: &[DictEntry]) -> Result<(), RepositoryError>;
-            async fn fetch_many(
-                &self,
-                limit: usize,
-                offset: usize,
-            ) -> Result<Dict, RepositoryError>;
-        }
-    }
-
     fn dict_with_words(words: &[&str]) -> Dict {
         let mut dict = Dict::new("default".into());
 
@@ -287,91 +275,94 @@ mod tests {
     }
 
     #[tokio::test]
-    async fn test_build_single_batch() {
-        let mut repo = MockRepo::new();
+    async fn test_from_stream_success() {
+        // 1. Setup Mocks (Same as before)
         let mut decoder = MockDecoder::new();
-        let mut seq = Sequence::new();
-
         decoder
             .expect_decode()
             .returning(|word| mock_decoding(word));
 
-        // FIRST CALL expectation (will be called first)
-        repo.expect_fetch_many()
-            .times(1) // Explicitly expect 1 call
-            .in_sequence(&mut seq) // Enforce order
-            .returning(|_, _| Ok(dict_with_words(&[TEST_WORD_1])));
+        // 2. Prepare Data
+        // We wrap the inner Vecs in Ok() because the stream expects Result<Vec<String>, RepositoryError>
+        let batches = vec![
+            Ok(vec![TEST_WORD_1.into(), TEST_WORD_2.into()]),
+            Ok(vec![TEST_WORD_3.into(), TEST_WORD_4.into()]),
+        ];
 
-        // SECOND CALL expectation (will be called second)
-        repo.expect_fetch_many()
-            .times(1)
-            .in_sequence(&mut seq)
-            .returning(|_, _| Ok(Dict::new("default_dict".into())));
+        // 3. Create a Stream from the Vec
+        // stream::iter converts an IntoIterator into a Stream
+        let stream = stream::iter(batches);
 
-        let data = LenValueMap::build(&decoder, &repo, 1)
+        // 4. Inject the stream (Dependency Injection)
+        let map = LenValueMap::from_stream(stream, &decoder)
             .await
-            .unwrap()
-            .into_data();
+            .expect("Should build map successfully");
 
-        assert_eq!(data.len(), 1);
+        // 5. Assertions
+        let data = map.into_data();
+        assert_eq!(data.len(), 2);
+        assert!(data.contains_key(&TEST_NUM_1_LEN));
+        assert!(data.contains_key(&TEST_NUM_3_LEN));
     }
 
     #[tokio::test]
-    async fn test_build_multiple_batches() {
-        let mut repo = MockRepo::new();
+    async fn test_from_stream_failure() {
         let mut decoder = MockDecoder::new();
-        let mut seq = Sequence::new();
-
         decoder
             .expect_decode()
             .returning(|word| mock_decoding(word));
 
-        repo.expect_fetch_many()
-            .times(1) // Explicitly expect 1 call
-            .in_sequence(&mut seq) // Enforce order
-            .returning(|_, _| Ok(dict_with_words(&[TEST_WORD_1])));
+        let batches = vec![
+            Ok(vec![TEST_WORD_1.into()]),
+            Err(RepositoryError::ConnectionFailed),
+            Ok(vec![TEST_WORD_3.into()]),
+        ];
 
-        repo.expect_fetch_many()
-            .times(1) // Explicitly expect 1 call
-            .in_sequence(&mut seq) // Enforce order
-            .returning(|_, _| Ok(dict_with_words(&[TEST_WORD_3]))); // word with different decoded length
+        let stream = stream::iter(batches);
+        let result = LenValueMap::from_stream(stream, &decoder).await;
 
-        repo.expect_fetch_many()
-            .times(1)
-            .in_sequence(&mut seq)
-            .returning(|_, _| Ok(Dict::new("default_dict".into())));
-
-        let data = LenValueMap::build(&decoder, &repo, 1)
-            .await
-            .unwrap()
-            .into_data();
-
-        assert_eq!(data.len(), 2);
+        match result {
+            // We match specifically on the Repository variant and the ConnectionFailed inner error
+            Err(LenValueMapError::Repository(RepositoryError::ConnectionFailed)) => {
+                // Success! The correct error type propagated up.
+            }
+            // If it's any other error (including a stringified one), we fail
+            _ => panic!(
+                "Expected LenValueMapError::Repository(ConnectionFailed), got {:?}",
+                result
+            ),
+        }
     }
 
     // #[tokio::test]
-    // async fn test_build_fetches_multiple_batches() {
+    // async fn test_build_multiple_batches() {
     //     let mut repo = MockRepo::new();
     //     let mut decoder = MockDecoder::new();
+    //     let mut seq = Sequence::new();
 
     //     decoder
     //         .expect_decode()
     //         .returning(|word| mock_decoding(word));
 
     //     repo.expect_fetch_many()
-    //         .with(eq("default"), eq(Some(2)), eq(Some(0)))
-    //         .return_once(|_, _, _| Ok(dict_with_words(&[TEST_WORD_1, TEST_WORD_2])));
+    //         .times(1) // Explicitly expect 1 call
+    //         .in_sequence(&mut seq) // Enforce order
+    //         .returning(|_, _| Ok(dict_with_words(&[TEST_WORD_1])));
 
     //     repo.expect_fetch_many()
-    //         .with(eq("default"), eq(Some(2)), eq(Some(2)))
-    //         .return_once(|_, _, _| Ok(dict_with_words(&[TEST_WORD_3, TEST_WORD_4])));
+    //         .times(1) // Explicitly expect 1 call
+    //         .in_sequence(&mut seq) // Enforce order
+    //         .returning(|_, _| Ok(dict_with_words(&[TEST_WORD_3]))); // word with different decoded length
 
     //     repo.expect_fetch_many()
-    //         .with(eq("default"), eq(Some(2)), eq(Some(4)))
-    //         .return_once(|_, _, _| Ok(Dict::new("default".into())));
-
-    //     let map = LenValueMap::build(&decoder, &repo, 2).await;
-    //     let data = map.into_data();
+    //         .times(1)
+    //         .in_sequence(&mut seq)
+    //         .returning(|_, _| Ok(Dict::new("default_dict".into())));
+
+    //     let data = LenValueMap::build(&decoder, &repo, 1)
+    //         .await
+    //         .unwrap()
+    //         .into_data();
 
     //     assert_eq!(data.len(), 2);
     // }

lib/src/core/sys_major/rules_pl.rs

@@ -133,8 +133,8 @@ pub fn get_rules() -> Rules {
 #[cfg(test)]
 mod tests {
     use super::*;
-    use crate::SystemDecoder;
     use crate::core::sys_major::Decoder;
+    use crate::traits::SystemDecoder;
 
     #[test]
     fn test_major_dict_pl_decode_0_1() {

lib/src/core/system.rs

@@ -1,7 +1,7 @@
 use serde::Deserialize;
 
-use crate::core::SystemDecoder;
-use crate::core::sys_major as major;
+use crate::core::sys_major::{self as major, LenValueMap};
+use crate::core::{DictRepository, SystemDecoder, SystemEncoder};
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Deserialize)]
 pub enum System {
@@ -28,3 +28,17 @@ pub fn create_decoder(system: &System) -> Box<dyn SystemDecoder> {
         System::MajorEn => Box::new(major::Decoder::new(major::rules_en::get_rules())),
     }
 }
+
+pub async fn create_encoder(system: &System, dict: &dyn DictRepository) -> Box<dyn SystemEncoder> {
+    // let decoder = create_decoder(&system);
+    let decoder = major::Decoder::new(match system {
+        System::MajorPl => major::rules_pl::get_rules(),
+        System::MajorEn => major::rules_en::get_rules(),
+    });
+    let stream = dict.stream_batches(100).await.unwrap(); // TODO
+    let lvmap = LenValueMap::from_stream(stream, &decoder).await.unwrap(); // TODO
+    match system {
+        System::MajorPl => Box::new(major::Encoder::new(lvmap)),
+        System::MajorEn => Box::new(major::Encoder::new(lvmap)),
+    }
+}

lib/src/core/traits.rs

@@ -1,3 +1,5 @@
+use futures::stream::BoxStream;
+
 use crate::core::entities::EncodedValue;
 use crate::core::errors::CodecError;
 
@@ -26,6 +28,13 @@ pub trait DictRepository: Send + Sync {
 
     /// Fetch a page of entries.
     async fn fetch_many(&self, limit: usize, offset: usize) -> Result<Dict, RepositoryError>;
+
+    /// Returns a cold stream that fetches strings in chunks.
+    /// The stream yields `Result<Vec<String>, RepositoryError>`.
+    async fn stream_batches(
+        &self,
+        batch_size: usize,
+    ) -> Result<BoxStream<'_, Result<Vec<String>, RepositoryError>>, RepositoryError>;
 }
 
 pub trait DictSource {

lib/src/infrastructure/sqlite_dict_repository.rs

@@ -1,6 +1,9 @@
 use crate::core::entities::{Dict, DictEntry};
 use crate::core::errors::RepositoryError;
 use crate::core::traits::DictRepository;
+use futures::stream::BoxStream;
+use futures::{StreamExt, TryStreamExt};
+
 use sqlx::{Row, SqlitePool, sqlite::SqliteConnectOptions};
 use std::collections::HashMap;
 use std::str::FromStr;
@@ -187,4 +190,42 @@ impl DictRepository for SqliteDictRepository {
             entries: entries_map,
         })
     }
+
+    async fn stream_batches(
+        &self,
+        batch_size: usize,
+    ) -> Result<BoxStream<'_, Result<Vec<String>, RepositoryError>>, RepositoryError> {
+        // 1. Resolve ID first
+        let dict_id = self.get_dict_id().await?;
+
+        // 2. Create the base query stream.
+        // We do NOT use limit/offset. We let the DB stream rows via a cursor.
+        let query_stream = sqlx::query("SELECT text FROM entries WHERE dictionary_id = ?")
+            .bind(dict_id)
+            .fetch(&self.pool);
+
+        // 3. Transform the stream using Functional combinators
+        let stream = query_stream
+            // Map SQLx errors to Domain errors
+            .map_err(|e| RepositoryError::StorageError(e.to_string()))
+            // Extract the String from the Row
+            .and_then(|row| async move {
+                // 'text' is the column name
+                let text: String = row
+                    .try_get("text")
+                    .map_err(|e| RepositoryError::StorageError(e.to_string()))?;
+                Ok(text)
+            })
+            // Group items into vectors of size `batch_size`
+            .try_chunks(batch_size)
+            // try_chunks returns a specific error type on failure, map it back
+            .map_err(|e| {
+                // logic to handle leftover elements if error occurs,
+                // but for simplicity, we treat stream errors as fatal here
+                RepositoryError::StorageError(e.to_string())
+            });
+
+        // 4. Box the stream to erase the complex iterator type (Type Erasure)
+        Ok(Box::pin(stream))
+    }
 }

lib/src/lib.rs

@@ -4,6 +4,7 @@ pub mod infrastructure;
 mod presentation;
 
 pub use self::application::config;
+pub use self::application::services::DictImporter;
 pub use self::core::system;
-pub use self::core::traits::SystemDecoder;
+pub use self::core::traits;
 pub use self::presentation::cli;

lib/src/presentation/cli/cli_args.rs

@@ -30,6 +30,9 @@ pub enum Command {
     /// Decode a word using given system
     Decode(DecodeArgs),
 
+    /// Encode a number using given system
+    Encode(EncodeArgs),
+
     /// Import dictionary
     ImportDict(ImportDictArgs),
 }
@@ -42,6 +45,15 @@ pub struct ServerArgs {
 
 #[derive(ClapArgs, Debug, Clone)]
 pub struct DecodeArgs {
+    #[arg(long, help = defaults::HELP_DEC_SYSTEM)]
+    pub system: Option<String>,
+
+    #[arg(long, help = defaults::HELP_DEC_INPUT)]
+    pub input: String,
+}
+
+#[derive(ClapArgs, Debug, Clone)]
+pub struct EncodeArgs {
     #[arg(long, help = defaults::HELP_ENC_SYSTEM)]
     pub system: Option<String>,
 

lib/src/presentation/cli/commands.rs

@@ -1,3 +1,4 @@
 pub mod decode;
+pub mod encode;
 pub mod import_dict;
 pub mod server;

lib/src/presentation/cli/commands/decode.rs

@@ -3,7 +3,7 @@ use crate::core::system;
 use tracing::debug;
 
 pub async fn run(config: DecoderConfig) {
-    debug!("Running greeter with config {:?}", config);
+    debug!("Running decoder with config {:?}", config);
     let decoder = system::create_decoder(&config.system);
     let result = decoder.decode(&config.input).unwrap();
     println!("{}", result.as_str());

lib/src/presentation/cli/commands/encode.rs

@@ -0,0 +1,10 @@
+use crate::application::config::EncoderConfig;
+use crate::core::{DictRepository, system};
+use tracing::debug;
+
+pub async fn run(config: EncoderConfig, dict: &dyn DictRepository) {
+    debug!("Running encoder with config {:?}", config);
+    let encoder = system::create_encoder(&config.system, dict).await;
+    let result = encoder.encode(&config.input);
+    println!("{:?}", result);
+}

lib/src/presentation/cli/commands/import_dict.rs

@@ -1,12 +1,8 @@
 use crate::application::{config::ImportDictConfig, services::DictImporter};
-use crate::core::traits::DictRepository;
 use crate::infrastructure::json_file_dict_source::JsonFileDictSource;
 use tracing::{debug, error, info};
 
-pub async fn run<R: DictRepository>(
-    config: ImportDictConfig,
-    repository: R,
-) -> Result<(), anyhow::Error> {
+pub async fn run(config: ImportDictConfig, importer: DictImporter) -> Result<(), anyhow::Error> {
     debug!("Importing dict with config {:?}", config);
 
     info!(
@@ -17,9 +13,6 @@ pub async fn run<R: DictRepository>(
     // Create the JSON file source (will auto-generate IDs starting from 1)
     let source = JsonFileDictSource::new(&config.path)?;
 
-    // Create the importer
-    let importer = DictImporter::new(&repository);
-
     // Perform the import (this will call create() first)
     match importer.import(source).await {
         Ok(()) => {

lib/src/presentation/cli/defaults.rs

@@ -10,8 +10,10 @@ pub const SYSTEM_NAME: &str = "major_pl";
 
 pub const HELP_PORT: &str = formatcp!("Override Port [default: {}]", PORT);
 pub const HELP_LOG: &str = formatcp!("Override Log Level [default: {}]", LOG_LEVEL);
+pub const HELP_DEC_SYSTEM: &str = formatcp!("System to use [default: {}]", SYSTEM_NAME);
+pub const HELP_DEC_INPUT: &str = formatcp!("Text to decode");
 pub const HELP_ENC_SYSTEM: &str = formatcp!("System to use [default: {}]", SYSTEM_NAME);
-pub const HELP_ENC_INPUT: &str = formatcp!("Text to decode");
+pub const HELP_ENC_INPUT: &str = formatcp!("Number to encode");
 pub const HELP_IMPORT_DICT_NAME: &str = formatcp!("Dictionary name");
 pub const HELP_IMPORT_DICT_INPUT: &str = formatcp!("Dictionary file path");