feat: add transcription backend contracts

src-tauri/src/transcription/crispasr.rs

@@ -0,0 +1,80 @@
+use std::path::PathBuf;
+
+use serde::{Deserialize, Serialize};
+
+use crate::error::{AppError, AppResult};
+
+use super::{Transcriber, TranscriptionInput, TranscriptionResult};
+
+#[derive(Debug, Clone, Serialize, Deserialize, PartialEq, Eq)]
+#[serde(rename_all = "camelCase")]
+pub struct CrispAsrConfig {
+    pub sidecar_name: Option<String>,
+    pub model_path: Option<PathBuf>,
+}
+
+#[derive(Debug, Clone)]
+pub struct CrispAsrTranscriber {
+    config: CrispAsrConfig,
+}
+
+impl CrispAsrTranscriber {
+    pub fn new(config: CrispAsrConfig) -> Self {
+        Self { config }
+    }
+
+    pub fn config(&self) -> &CrispAsrConfig {
+        &self.config
+    }
+}
+
+impl Transcriber for CrispAsrTranscriber {
+    fn transcribe(&self, input: TranscriptionInput) -> AppResult<TranscriptionResult> {
+        let Some(model_path) = &self.config.model_path else {
+            return Err(AppError::ModelNotInstalled(input.options.model_id));
+        };
+
+        if self.config.sidecar_name.is_none() {
+            return Err(AppError::SidecarNotConfigured);
+        }
+
+        Ok(TranscriptionResult {
+            text: format!(
+                "Transcrição local pendente via CrispASR para {} usando {}.",
+                input.audio_path.display(),
+                model_path.display()
+            ),
+            backend: "crispasr".to_string(),
+            model_id: input.options.model_id,
+            detected_language: input.options.language,
+        })
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use std::path::PathBuf;
+
+    use crate::error::AppError;
+    use crate::models::DEFAULT_MODEL_ID;
+    use crate::transcription::{Transcriber, TranscriptionInput, TranscriptionOptions};
+
+    use super::{CrispAsrConfig, CrispAsrTranscriber};
+
+    #[test]
+    fn missing_model_returns_clear_error() {
+        let transcriber = CrispAsrTranscriber::new(CrispAsrConfig {
+            sidecar_name: Some("crispasr".to_string()),
+            model_path: None,
+        });
+
+        let err = transcriber
+            .transcribe(TranscriptionInput {
+                audio_path: PathBuf::from("sample.wav"),
+                options: TranscriptionOptions::default(),
+            })
+            .expect_err("modelo ausente deve falhar");
+
+        assert_eq!(err, AppError::ModelNotInstalled(DEFAULT_MODEL_ID.to_string()));
+    }
+}

src-tauri/src/transcription/mod.rs

@@ -0,0 +1,47 @@
+use std::path::PathBuf;
+
+use serde::{Deserialize, Serialize};
+
+use crate::error::AppResult;
+use crate::models::DEFAULT_MODEL_ID;
+
+pub mod crispasr;
+pub mod openai;
+
+#[derive(Debug, Clone, Serialize, Deserialize, PartialEq, Eq)]
+#[serde(rename_all = "camelCase")]
+pub struct TranscriptionInput {
+    pub audio_path: PathBuf,
+    pub options: TranscriptionOptions,
+}
+
+#[derive(Debug, Clone, Serialize, Deserialize, PartialEq, Eq)]
+#[serde(rename_all = "camelCase")]
+pub struct TranscriptionOptions {
+    pub model_id: String,
+    pub language: Option<String>,
+    pub timestamps: bool,
+}
+
+impl Default for TranscriptionOptions {
+    fn default() -> Self {
+        Self {
+            model_id: DEFAULT_MODEL_ID.to_string(),
+            language: None,
+            timestamps: false,
+        }
+    }
+}
+
+#[derive(Debug, Clone, Serialize, Deserialize, PartialEq, Eq)]
+#[serde(rename_all = "camelCase")]
+pub struct TranscriptionResult {
+    pub text: String,
+    pub backend: String,
+    pub model_id: String,
+    pub detected_language: Option<String>,
+}
+
+pub trait Transcriber {
+    fn transcribe(&self, input: TranscriptionInput) -> AppResult<TranscriptionResult>;
+}

src-tauri/src/transcription/openai.rs

@@ -0,0 +1,19 @@
+use serde::{Deserialize, Serialize};
+
+#[derive(Debug, Clone, Serialize, Deserialize, PartialEq, Eq)]
+#[serde(rename_all = "camelCase")]
+pub struct OpenAiTranscriptionConfig {
+    pub endpoint: String,
+    pub model: String,
+    pub language: Option<String>,
+}
+
+impl Default for OpenAiTranscriptionConfig {
+    fn default() -> Self {
+        Self {
+            endpoint: "https://api.openai.com/v1/audio/transcriptions".to_string(),
+            model: "whisper-1".to_string(),
+            language: None,
+        }
+    }
+}