cqlite-core 0.13.0

//! Schema exporter for discovery output formats.
//!
//! Generates CQL `CREATE TABLE` statements, optional JSON exports (experimental
//! feature), and schema comparison reports from discovered [`SchemaInfo`].

use crate::Result;

use super::model::{SchemaInfo, TypeInfo};

/// Schema exporter for generating output formats
#[derive(Debug)]
pub struct SchemaExporter {
    // Implementation details for export
}

impl SchemaExporter {
    pub(super) fn new() -> Self {
        Self {}
    }

    /// Generate CQL CREATE TABLE statement
    pub(super) async fn generate_cql(&self, schema: &SchemaInfo) -> Result<String> {
        let mut cql = String::new();

        // CREATE TABLE statement
        cql.push_str(&format!(
            "CREATE TABLE {}.{} (\n",
            schema.keyspace, schema.table
        ));

        // Partition key columns
        for column in &schema.partition_key {
            cql.push_str(&format!(
                "    {} {},\n",
                column.name,
                self.format_column_type(&column.type_info)
            ));
        }

        // Clustering key columns
        for clustering in &schema.clustering_keys {
            cql.push_str(&format!(
                "    {} {},\n",
                clustering.name, clustering.data_type
            ));
        }

        // Static columns
        for column in &schema.static_columns {
            let static_modifier = if column.is_static { " STATIC" } else { "" };
            cql.push_str(&format!(
                "    {} {}{},\n",
                column.name,
                self.format_column_type(&column.type_info),
                static_modifier
            ));
        }

        // Regular columns
        for column in &schema.regular_columns {
            cql.push_str(&format!(
                "    {} {},\n",
                column.name,
                self.format_column_type(&column.type_info)
            ));
        }

        // Primary key definition
        if !schema.partition_key.is_empty() {
            let partition_keys: Vec<String> = schema
                .partition_key
                .iter()
                .map(|col| col.name.clone())
                .collect();

            if schema.clustering_keys.is_empty() {
                cql.push_str(&format!("    PRIMARY KEY ({})", partition_keys.join(", ")));
            } else {
                let clustering_keys: Vec<String> = schema
                    .clustering_keys
                    .iter()
                    .map(|col| col.name.clone())
                    .collect();

                if partition_keys.len() == 1 {
                    cql.push_str(&format!(
                        "    PRIMARY KEY ({}, {})",
                        partition_keys[0],
                        clustering_keys.join(", ")
                    ));
                } else {
                    cql.push_str(&format!(
                        "    PRIMARY KEY (({}) {})",
                        partition_keys.join(", "),
                        clustering_keys.join(", ")
                    ));
                }
            }
        }

        cql.push_str("\n);");

        // Add clustering order if specified
        if !schema.clustering_keys.is_empty() {
            let mut clustering_order = Vec::new();
            for clustering in &schema.clustering_keys {
                let order = match clustering.order {
                    crate::schema::ClusteringOrder::Asc => "ASC",
                    crate::schema::ClusteringOrder::Desc => "DESC",
                };
                clustering_order.push(format!("{} {}", clustering.name, order));
            }

            if clustering_order.iter().any(|o| o.contains("DESC")) {
                cql.push_str(&format!(
                    "\nWITH CLUSTERING ORDER BY ({});",
                    clustering_order.join(", ")
                ));
            }
        }

        // Add table options if present
        let mut options = Vec::new();

        if let Some(compaction) = &schema.table_options.compaction {
            options.push(format!("compaction = {{'class': '{}'}}", compaction.class));
        }

        if let Some(compression) = &schema.table_options.compression {
            options.push(format!(
                "compression = {{'algorithm': '{}'}}",
                compression.algorithm
            ));
        }

        if let Some(gc_grace) = schema.table_options.gc_grace_seconds {
            options.push(format!("gc_grace_seconds = {}", gc_grace));
        }

        if let Some(ttl) = schema.table_options.default_time_to_live {
            options.push(format!("default_time_to_live = {}", ttl));
        }

        if !options.is_empty() {
            if !cql.ends_with(';') {
                cql.push_str(" WITH ");
            } else {
                cql.pop(); // Remove the semicolon
                cql.push_str("\nWITH ");
            }
            cql.push_str(&options.join("\n  AND "));
            cql.push(';');
        }

        Ok(cql)
    }

    /// Format column type information for CQL
    #[allow(clippy::only_used_in_recursion)]
    fn format_column_type(&self, type_info: &TypeInfo) -> String {
        match type_info.type_id.as_str() {
            "list" => {
                if let Some(element_type) = &type_info.element_type {
                    format!("list<{}>", self.format_column_type(element_type))
                } else {
                    "list<text>".to_string()
                }
            }
            "set" => {
                if let Some(element_type) = &type_info.element_type {
                    format!("set<{}>", self.format_column_type(element_type))
                } else {
                    "set<text>".to_string()
                }
            }
            "map" => {
                if let (Some(key_type), Some(value_type)) =
                    (&type_info.key_type, &type_info.value_type)
                {
                    format!(
                        "map<{}, {}>",
                        self.format_column_type(key_type),
                        self.format_column_type(value_type)
                    )
                } else {
                    "map<text, text>".to_string()
                }
            }
            "tuple" => {
                if let Some(tuple_elements) = &type_info.tuple_elements {
                    let element_types: Vec<String> = tuple_elements
                        .iter()
                        .map(|t| self.format_column_type(t))
                        .collect();
                    format!("tuple<{}>", element_types.join(", "))
                } else {
                    "tuple<text>".to_string()
                }
            }
            "frozen" => {
                if let Some(element_type) = &type_info.element_type {
                    format!("frozen<{}>", self.format_column_type(element_type))
                } else {
                    "frozen<text>".to_string()
                }
            }
            _ => type_info.type_id.clone(),
        }
    }

    /// Export schema as JSON
    #[cfg(feature = "experimental")]
    pub(super) async fn export_json(&self, schema: &SchemaInfo) -> Result<String> {
        self.export_json_with_config(
            schema,
            &crate::schema::json_exporter::JsonExportConfig::default(),
        )
        .await
    }

    /// Export schema as JSON with custom configuration
    #[cfg(feature = "experimental")]
    pub(super) async fn export_json_with_config(
        &self,
        schema: &SchemaInfo,
        config: &crate::schema::json_exporter::JsonExportConfig,
    ) -> Result<String> {
        let exporter = crate::schema::json_exporter::JsonExporter::with_config(config.clone());
        exporter.export_schema_info(schema)
    }

    #[cfg(not(feature = "experimental"))]
    #[allow(dead_code)]
    pub(super) async fn export_json(&self, _schema: &SchemaInfo) -> Result<String> {
        Err(crate::error::Error::unsupported_format(
            "JSON export requires experimental feature",
        ))
    }

    #[cfg(not(feature = "experimental"))]
    #[allow(dead_code)]
    pub(super) async fn export_json_with_config<T>(
        &self,
        _schema: &SchemaInfo,
        _config: &T, // Generic placeholder for when experimental feature is disabled
    ) -> Result<String> {
        Err(crate::error::Error::unsupported_format(
            "JSON export requires experimental feature",
        ))
    }

    /// Export schema as compact JSON (minimal format)
    #[allow(dead_code)]
    #[cfg(feature = "experimental")]
    async fn export_json_compact(&self, schema: &SchemaInfo) -> Result<String> {
        let config = crate::schema::json_exporter::JsonExportConfig {
            format_variant: crate::schema::json_exporter::JsonFormat::Compact,
            include_metadata: false,
            include_performance_metrics: false,
            include_type_details: false,
            pretty_format: false,
            ..Default::default()
        };
        self.export_json_with_config(schema, &config).await
    }

    /// Export schema for API documentation (OpenAPI-compatible format)
    #[allow(dead_code)]
    #[cfg(feature = "experimental")]
    async fn export_json_openapi(&self, schema: &SchemaInfo) -> Result<String> {
        let config = crate::schema::json_exporter::JsonExportConfig {
            format_variant: crate::schema::json_exporter::JsonFormat::OpenApi,
            include_documentation: true,
            include_type_details: true,
            include_metadata: false,
            ..Default::default()
        };
        self.export_json_with_config(schema, &config).await
    }

    /// Export schema for data pipeline tools
    #[allow(dead_code)]
    #[cfg(feature = "experimental")]
    async fn export_json_pipeline(&self, schema: &SchemaInfo) -> Result<String> {
        let config = crate::schema::json_exporter::JsonExportConfig {
            format_variant: crate::schema::json_exporter::JsonFormat::DataPipeline,
            include_type_details: true,
            include_table_options: false,
            include_performance_metrics: true,
            ..Default::default()
        };
        self.export_json_with_config(schema, &config).await
    }

    /// Generate schema comparison report
    pub(super) async fn generate_comparison_report(
        &self,
        _schema1: &SchemaInfo,
        _schema2: &SchemaInfo,
    ) -> Result<String> {
        // TODO: Implement schema comparison logic for production
        // This is a minimal viable stub to enable compilation and basic testing
        // Real implementation would compare schemas and generate detailed reports
        Ok(
            "Schema comparison not yet implemented. Both schemas analyzed as equivalent."
                .to_string(),
        )
    }
}

#[cfg(test)]
mod tests {
    use super::*;
    use crate::schema::discovery::model::{
        ConsistencyResults, DiscoveryMethod, DiscoveryMetrics, SchemaMetadata, TableOptions,
        ValidationResults, ValidationStatus,
    };
    use std::collections::HashMap;

    #[tokio::test]
    async fn test_generate_comparison_report_stub() {
        let exporter = SchemaExporter::new();

        let schema_info = SchemaInfo {
            keyspace: "test".to_string(),
            table: "users".to_string(),
            partition_key: Vec::new(),
            clustering_keys: Vec::new(),
            regular_columns: Vec::new(),
            static_columns: Vec::new(),
            collection_types: HashMap::new(),
            user_defined_types: Vec::new(),
            indexes: Vec::new(),
            table_options: TableOptions {
                compaction: None,
                compression: None,
                caching: None,
                bloom_filter_fp_chance: None,
                gc_grace_seconds: None,
                default_time_to_live: None,
                memtable_flush_period_in_ms: None,
                additional_properties: HashMap::new(),
            },
            metadata: SchemaMetadata {
                discovered_at: std::time::UNIX_EPOCH,
                source_files: Vec::new(),
                total_rows_sampled: 0,
                cassandra_version: None,
                discovery_method: DiscoveryMethod::HeaderMetadata,
                version: 1,
                validation_results: ValidationResults {
                    status: ValidationStatus::Valid,
                    errors: Vec::new(),
                    warnings: Vec::new(),
                    consistency_results: ConsistencyResults {
                        files_analyzed: 0,
                        schema_mismatches: 0,
                        type_inconsistencies: Vec::new(),
                        udt_conflicts: Vec::new(),
                    },
                },
                performance_metrics: DiscoveryMetrics {
                    total_time_ms: 0,
                    header_parsing_time_ms: 0,
                    data_sampling_time_ms: 0,
                    type_inference_time_ms: 0,
                    validation_time_ms: 0,
                    peak_memory_usage_bytes: 0,
                },
            },
        };

        // Test that the stub method executes without panicking and returns expected result
        let result = exporter
            .generate_comparison_report(&schema_info, &schema_info)
            .await;
        assert!(
            result.is_ok(),
            "generate_comparison_report stub should return Ok"
        );

        let report = result.unwrap();
        assert!(
            report.contains("Schema comparison not yet implemented"),
            "Report should contain stub message"
        );
    }
}