importer feature

crates/adapters/importer/src/mapper.rs

@@ -0,0 +1,192 @@
+use crate::types::{AnnotatedRow, DomainField, FieldMapping, ImportRow, ParsedFile, RowResult, Transform};
+
+pub fn apply_mapping(file: &ParsedFile, mappings: &[FieldMapping]) -> Vec<AnnotatedRow> {
+    file.rows.iter().map(|row| {
+        let result = map_row(row, &file.columns, mappings);
+        AnnotatedRow { result, is_duplicate: false }
+    }).collect()
+}
+
+fn map_row(row: &[String], columns: &[String], mappings: &[FieldMapping]) -> RowResult {
+    let mut import_row = ImportRow::default();
+    let mut errors = Vec::new();
+
+    for mapping in mappings {
+        let Some(col_idx) = columns.iter().position(|c| c == &mapping.source_column) else {
+            continue;
+        };
+        let raw_value = row.get(col_idx).map(|s| s.as_str()).unwrap_or("").trim();
+        if raw_value.is_empty() {
+            continue;
+        }
+        if let Some(value) = apply_transform(raw_value, &mapping.transform, &mut errors) {
+            set_field(&mut import_row, &mapping.domain_field, value);
+        }
+    }
+
+    if import_row.title.is_none() && import_row.external_metadata_id.is_none() {
+        errors.push("missing required field: title or external_metadata_id".into());
+    }
+    if import_row.rating.is_none() {
+        errors.push("missing required field: rating".into());
+    }
+    if import_row.watched_at.is_none() {
+        errors.push("missing required field: watched_at".into());
+    }
+
+    if errors.is_empty() {
+        RowResult::Valid(import_row)
+    } else {
+        let raw = columns.iter()
+            .zip(row.iter())
+            .map(|(c, v)| (c.clone(), v.clone()))
+            .collect();
+        RowResult::Invalid { errors, raw }
+    }
+}
+
+fn apply_transform(value: &str, transform: &Transform, errors: &mut Vec<String>) -> Option<String> {
+    match transform {
+        Transform::Identity => Some(value.to_string()),
+        Transform::DateFormat(_) => Some(value.to_string()),
+        Transform::RatingScale(factor) => {
+            match value.parse::<f64>() {
+                Ok(n) => Some((n * factor).round().to_string()),
+                Err(_) => {
+                    errors.push(format!("rating '{}' is not a number", value));
+                    None
+                }
+            }
+        }
+    }
+}
+
+fn set_field(row: &mut ImportRow, field: &DomainField, value: String) {
+    match field {
+        DomainField::Title => row.title = Some(value),
+        DomainField::ReleaseYear => row.release_year = Some(value),
+        DomainField::Director => row.director = Some(value),
+        DomainField::Rating => row.rating = Some(value),
+        DomainField::WatchedAt => row.watched_at = Some(value),
+        DomainField::Comment => row.comment = Some(value),
+        DomainField::ExternalMetadataId => row.external_metadata_id = Some(value),
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::types::{DomainField, FieldMapping, ParsedFile, RowResult, Transform};
+
+    fn sample_file() -> ParsedFile {
+        ParsedFile {
+            columns: vec!["Name".into(), "Stars".into(), "Date".into()],
+            rows: vec![
+                vec!["Inception".into(), "10".into(), "2024-01-15".into()],
+                vec!["Dune".into(), "8".into(), "2024-02-20".into()],
+                vec!["".into(), "3".into(), "2024-03-01".into()], // missing title → invalid
+            ],
+        }
+    }
+
+    fn full_mappings() -> Vec<FieldMapping> {
+        vec![
+            FieldMapping { source_column: "Name".into(), domain_field: DomainField::Title, transform: Transform::Identity },
+            FieldMapping { source_column: "Stars".into(), domain_field: DomainField::Rating, transform: Transform::RatingScale(0.5) },
+            FieldMapping { source_column: "Date".into(), domain_field: DomainField::WatchedAt, transform: Transform::Identity },
+        ]
+    }
+
+    #[test]
+    fn maps_valid_rows() {
+        let results = apply_mapping(&sample_file(), &full_mappings());
+        assert_eq!(results.len(), 3);
+        // First two rows are valid
+        assert!(matches!(results[0].result, RowResult::Valid(_)));
+        assert!(matches!(results[1].result, RowResult::Valid(_)));
+        // is_duplicate defaults to false
+        assert!(!results[0].is_duplicate);
+    }
+
+    #[test]
+    fn applies_rating_scale_transform() {
+        let results = apply_mapping(&sample_file(), &full_mappings());
+        if let RowResult::Valid(row) = &results[0].result {
+            // 10 * 0.5 = 5
+            assert_eq!(row.rating.as_deref(), Some("5"));
+        } else {
+            panic!("expected Valid");
+        }
+    }
+
+    #[test]
+    fn marks_missing_required_fields_invalid() {
+        let results = apply_mapping(&sample_file(), &full_mappings());
+        // Row 2 has empty title
+        assert!(matches!(results[2].result, RowResult::Invalid { .. }));
+    }
+
+    #[test]
+    fn ignores_unmapped_columns() {
+        let mappings = vec![
+            FieldMapping { source_column: "Name".into(), domain_field: DomainField::Title, transform: Transform::Identity },
+        ];
+        let file = ParsedFile {
+            columns: vec!["Name".into(), "Extra".into()],
+            rows: vec![vec!["Inception".into(), "ignored".into()]],
+        };
+        let results = apply_mapping(&file, &mappings);
+        assert_eq!(results.len(), 1);
+        // Missing rating and watched_at → invalid
+        assert!(matches!(results[0].result, RowResult::Invalid { .. }));
+    }
+
+    #[test]
+    fn nonexistent_source_column_skipped() {
+        let mappings = vec![
+            FieldMapping { source_column: "DoesNotExist".into(), domain_field: DomainField::Title, transform: Transform::Identity },
+        ];
+        let file = ParsedFile {
+            columns: vec!["Name".into()],
+            rows: vec![vec!["Inception".into()]],
+        };
+        let results = apply_mapping(&file, &mappings);
+        // Column not found → field not set → invalid (missing title, rating, watched_at)
+        assert!(matches!(results[0].result, RowResult::Invalid { .. }));
+    }
+
+    #[test]
+    fn collects_all_errors_not_just_first() {
+        let mappings = vec![
+            FieldMapping { source_column: "Name".into(), domain_field: DomainField::Title, transform: Transform::Identity },
+            FieldMapping { source_column: "Stars".into(), domain_field: DomainField::Rating, transform: Transform::RatingScale(0.5) },
+            // no watched_at mapping
+        ];
+        let file = ParsedFile {
+            columns: vec!["Name".into(), "Stars".into()],
+            rows: vec![vec!["Inception".into(), "notanumber".into()]],
+        };
+        let results = apply_mapping(&file, &mappings);
+        if let RowResult::Invalid { errors, .. } = &results[0].result {
+            assert!(errors.iter().any(|e| e.contains("not a number")), "expected rating error, got: {:?}", errors);
+            assert!(errors.iter().any(|e| e.contains("watched_at")), "expected watched_at error, got: {:?}", errors);
+        } else {
+            panic!("expected Invalid");
+        }
+    }
+
+    #[test]
+    fn non_numeric_rating_produces_error_in_row() {
+        let mappings = vec![
+            FieldMapping { source_column: "Name".into(), domain_field: DomainField::Title, transform: Transform::Identity },
+            FieldMapping { source_column: "Stars".into(), domain_field: DomainField::Rating, transform: Transform::RatingScale(0.5) },
+            FieldMapping { source_column: "Date".into(), domain_field: DomainField::WatchedAt, transform: Transform::Identity },
+        ];
+        let file = ParsedFile {
+            columns: vec!["Name".into(), "Stars".into(), "Date".into()],
+            rows: vec![vec!["Inception".into(), "five".into(), "2024-01-15".into()]],
+        };
+        let results = apply_mapping(&file, &mappings);
+        assert!(matches!(results[0].result, RowResult::Invalid { .. }));
+    }
+}