llmgrep 3.2.0

//! SQL query builders for search operations.
//!
//! This module provides functions for building SQL queries with various
//! filtering options.

use crate::algorithm::{symbol_set_filter_strategy, SymbolSetStrategy};
use crate::query::options::{CoverageFilter, MetricsOptions};
use crate::query::util::{like_pattern, like_prefix};
use crate::SortMode;
use rusqlite::{Connection, ToSql};
use std::collections::HashSet;
use std::path::PathBuf;

/// Check if the `symbol_fts` FTS5 virtual table exists in the database.
pub(crate) fn check_symbol_fts_exists(conn: &Connection) -> Result<bool, rusqlite::Error> {
    let mut stmt = conn.prepare(
        "SELECT name FROM sqlite_master WHERE type='table' AND name='symbol_fts'",
    )?;
    Ok(stmt.exists([])?)
}

/// Convert a user search query into an FTS5 MATCH expression with OR semantics.
///
/// FTS5 defaults to AND for space-separated terms, which causes multi-word
/// queries like "Mutex RwLock" to require all words. This function splits
/// the query into tokens and joins them with `OR`, so any matching token
/// returns results.
///
/// Each token is double-quoted to prevent FTS5 from interpreting special
/// characters (e.g. `*`, `-`, `OR`) as query operators.
pub(crate) fn fts5_or_query(query: &str) -> String {
    let tokens: Vec<&str> = query.split_whitespace().filter(|t| !t.is_empty()).collect();
    match tokens.len() {
        0 => String::new(),
        1 => {
            let token = tokens[0].replace('"', "\"\"");
            format!("\"{}\"", token)
        }
        _ => tokens
            .into_iter()
            .map(|t| {
                let escaped = t.replace('"', "\"\"");
                format!("\"{}\"", escaped)
            })
            .collect::<Vec<_>>()
            .join(" OR "),
    }
}

/// Expand a normalized kind into all equivalent AST kind strings for
/// cross-language search. Magellan normalizes `Class` to `struct`, but
/// raw tree-sitter kinds vary by language (e.g., `class_definition`,
/// `struct_item`). This mapping ensures `--kind class` finds symbols
/// regardless of which language they were indexed from.
fn expand_kind_aliases(kind: &str) -> Vec<String> {
    let mut result = HashSet::new();
    result.insert(kind.to_string());
    match kind {
        "class" | "struct" => {
            result.insert("class".to_string());
            result.insert("struct".to_string());
            result.insert("class_definition".to_string());
            result.insert("class_declaration".to_string());
            result.insert("class_expression".to_string());
            result.insert("class_specifier".to_string());
            result.insert("struct_item".to_string());
            result.insert("struct_specifier".to_string());
        }
        "fn" | "function" | "method" => {
            result.insert("fn".to_string());
            result.insert("function".to_string());
            result.insert("function_item".to_string());
            result.insert("function_definition".to_string());
            result.insert("method_definition".to_string());
            result.insert("arrow_function".to_string());
            result.insert("method".to_string());
        }
        "enum" => {
            result.insert("enum".to_string());
            result.insert("enum_item".to_string());
            result.insert("enum_definition".to_string());
            result.insert("enum_declaration".to_string());
            result.insert("enum_specifier".to_string());
        }
        "trait" | "interface" => {
            result.insert("trait".to_string());
            result.insert("interface".to_string());
            result.insert("trait_item".to_string());
            result.insert("interface_declaration".to_string());
            result.insert("interface_definition".to_string());
        }
        "module" | "namespace" | "package" => {
            result.insert("module".to_string());
            result.insert("namespace".to_string());
            result.insert("package".to_string());
            result.insert("module_item".to_string());
            result.insert("namespace_definition".to_string());
        }
        "typealias" | "type_alias" | "type" => {
            result.insert("typealias".to_string());
            result.insert("type_alias".to_string());
            result.insert("type".to_string());
            result.insert("type_alias_item".to_string());
            result.insert("type_definition".to_string());
            result.insert("type_declaration".to_string());
        }
        "constant" | "const" => {
            result.insert("constant".to_string());
            result.insert("const".to_string());
            result.insert("const_item".to_string());
        }
        "variable" | "var" | "field" | "property" => {
            result.insert("variable".to_string());
            result.insert("var".to_string());
            result.insert("field".to_string());
            result.insert("property".to_string());
            result.insert("field_declaration".to_string());
            result.insert("property_definition".to_string());
            result.insert("variable_declaration".to_string());
        }
        _ => {}
    }
    result.into_iter().collect()
}

#[allow(clippy::too_many_arguments)] // All parameters are needed for flexible query building
pub(crate) fn build_search_query(
    query: &str,
    path_filter: Option<&PathBuf>,
    kind_filter: Option<&str>,
    language_filter: Option<&str>,
    use_regex: bool,
    count_only: bool,
    limit: usize,
    metrics: MetricsOptions,
    sort_by: SortMode,
    symbol_id: Option<&str>,
    fqn_pattern: Option<&str>,
    exact_fqn: Option<&str>,
    has_ast_table: bool,
    ast_kinds: &[String],
    _min_depth: Option<usize>,
    _max_depth: Option<usize>,
    inside_kind: Option<&str>,
    contains_kind: Option<&str>,
    symbol_set_filter: Option<&Vec<String>>,
    has_coverage: bool,
    coverage_filter: Option<CoverageFilter>,
    use_fts5: bool,
) -> (String, Vec<Box<dyn ToSql>>, SymbolSetStrategy) {
    let mut params: Vec<Box<dyn ToSql>> = Vec::new();
    let mut where_clauses = Vec::new();

    // SymbolId mode: Direct lookup by BLAKE3 hash (bypasses name search)
    if let Some(sid) = symbol_id {
        where_clauses.push("json_extract(s.data, '$.symbol_id') = ?".to_string());
        params.push(Box::new(sid.to_string()));
    } else if !use_regex {
        // Standard name-based search (only if not using symbol_id)
        if use_fts5 && !query.trim().is_empty() {
            // FTS5 with OR semantics for multi-word queries
            let fts_query = fts5_or_query(query);
            where_clauses.push(
                "s.id IN (SELECT rowid FROM symbol_fts WHERE symbol_fts MATCH ?)".to_string(),
            );
            params.push(Box::new(fts_query));
        } else {
            // Fallback to LIKE when FTS5 is unavailable or query is empty
            let like_query = like_pattern(query);
            where_clauses.push(
                "(s.name LIKE ? ESCAPE '\\' OR s.display_fqn LIKE ? ESCAPE '\\' OR s.fqn LIKE ? ESCAPE '\\')"
                    .to_string(),
            );
            params.push(Box::new(like_query.clone()));
            params.push(Box::new(like_query.clone()));
            params.push(Box::new(like_query));
        }
    }

    // FQN pattern filter (LIKE match on canonical_fqn)
    if let Some(pattern) = fqn_pattern {
        where_clauses
            .push("json_extract(s.data, '$.canonical_fqn') LIKE ? ESCAPE '\\'".to_string());
        params.push(Box::new(pattern.to_string()));
    }

    // Exact FQN filter (exact match on canonical_fqn)
    if let Some(exact) = exact_fqn {
        where_clauses.push("json_extract(s.data, '$.canonical_fqn') = ?".to_string());
        params.push(Box::new(exact.to_string()));
    }

    if let Some(path) = path_filter {
        where_clauses.push("f.file_path LIKE ? ESCAPE '\\'".to_string());
        params.push(Box::new(like_prefix(path)));
    }

    if let Some(kind) = kind_filter {
        let raw_kinds: Vec<&str> = kind
            .split(',')
            .map(|s| s.trim())
            .filter(|s| !s.is_empty())
            .collect();
        let mut all_kinds = HashSet::new();
        for k in &raw_kinds {
            for alias in expand_kind_aliases(k) {
                all_kinds.insert(alias);
            }
        }
        let kinds: Vec<String> = all_kinds.into_iter().collect();
        if kinds.len() == 1 {
            where_clauses.push("(s.kind_normalized = ? OR s.kind = ?)".to_string());
            params.push(Box::new(kinds[0].clone()));
            params.push(Box::new(kinds[0].clone()));
        } else if !kinds.is_empty() {
            let placeholders = kinds.iter().map(|_| "?").collect::<Vec<_>>().join(",");
            where_clauses.push(format!(
                "(s.kind_normalized IN ({}) OR s.kind IN ({}))",
                placeholders, placeholders
            ));
            for k in &kinds {
                params.push(Box::new(k.clone()));
            }
            for k in &kinds {
                params.push(Box::new(k.clone()));
            }
        }
    }

    // Language filter: Filter by inferred language from file extension
    // Note: This uses file extension matching since language labels aren't
    // directly stored in graph_entities. A future enhancement could use
    // label tables for faster filtering.
    if let Some(language) = language_filter {
        let extensions = match language {
            "rust" => ".rs",
            "python" => ".py",
            "javascript" => ".js",
            "typescript" => ".ts",
            "c" => ".c",
            "cpp" => ".cpp",
            "java" => ".java",
            "go" => ".go",
            _ => "", // Unknown language - no filter
        };
        if !extensions.is_empty() {
            where_clauses.push("f.file_path LIKE ? ESCAPE '\\'".to_string());
            params.push(Box::new(format!("%{}", extensions)));
        }
    }

    // AST kind filter: Filter by AST node kind(s) using overlap matching
    // This uses an EXISTS subquery to handle cases where AST nodes overlap
    // with symbol spans but don't have exact byte matches
    if !ast_kinds.is_empty() && has_ast_table {
        if ast_kinds.len() == 1 {
            // Single kind - use EXISTS with overlap check
            where_clauses.push(
                "EXISTS (
                    SELECT 1 FROM ast_nodes
                    WHERE kind = ?
                    AND byte_start < json_extract(s.data, '$.byte_end')
                    AND byte_end > json_extract(s.data, '$.byte_start')
                )"
                .to_string(),
            );
            params.push(Box::new(ast_kinds[0].clone()));
        } else {
            // Multiple kinds - use EXISTS with IN and overlap check
            let placeholders = vec!["?"; ast_kinds.len()].join(",");
            where_clauses.push(format!(
                "EXISTS (
                    SELECT 1 FROM ast_nodes
                    WHERE kind IN ({})
                    AND byte_start < json_extract(s.data, '$.byte_end')
                    AND byte_end > json_extract(s.data, '$.byte_start')
                )",
                placeholders
            ));
            for kind in ast_kinds {
                params.push(Box::new(kind.clone()));
            }
        }
    }
    // If ast_nodes table doesn't exist, we silently ignore the filter
    // (graceful degradation)

    // Add metrics filter WHERE clauses
    // For filters, we use IS NOT NULL to ensure symbols have metrics
    if let Some(min_cc) = metrics.min_complexity {
        where_clauses.push(
            "(sm.cyclomatic_complexity IS NOT NULL AND sm.cyclomatic_complexity >= ?)".to_string(),
        );
        params.push(Box::new(min_cc as i64));
    }
    if let Some(max_cc) = metrics.max_complexity {
        where_clauses.push(
            "(sm.cyclomatic_complexity IS NOT NULL AND sm.cyclomatic_complexity <= ?)".to_string(),
        );
        params.push(Box::new(max_cc as i64));
    }
    if let Some(min_fi) = metrics.min_fan_in {
        where_clauses.push("(sm.fan_in IS NOT NULL AND sm.fan_in >= ?)".to_string());
        params.push(Box::new(min_fi as i64));
    }
    if let Some(min_fo) = metrics.min_fan_out {
        where_clauses.push("(sm.fan_out IS NOT NULL AND sm.fan_out >= ?)".to_string());
        params.push(Box::new(min_fo as i64));
    }

    // Structural search: --inside KIND (find descendants within any ancestor of type KIND)
    if let Some(inside_kind) = inside_kind {
        if has_ast_table {
            // Use a correlated EXISTS subquery with recursive CTE to check all ancestors
            // This handles nested structures like: function -> block -> closure
            where_clauses.push(
                "EXISTS (
                    WITH RECURSIVE ancestors AS (
                        SELECT id, parent_id FROM ast_nodes WHERE id = an.id
                        UNION ALL
                        SELECT a.id, a.parent_id FROM ast_nodes a
                        JOIN ancestors anc ON a.id = anc.parent_id
                        WHERE a.parent_id IS NOT NULL
                    )
                    SELECT 1 FROM ast_nodes p
                    JOIN ancestors anc ON p.id = anc.parent_id
                    WHERE p.kind = ?
                )"
                .to_string(),
            );
            params.push(Box::new(inside_kind.to_string()));
        }
    }

    // Structural search: --contains KIND (find parents with children of type KIND)
    if let Some(contains_kind) = contains_kind {
        if has_ast_table {
            where_clauses.push("an.id IN (SELECT parent_id FROM ast_nodes WHERE kind = ? AND parent_id IS NOT NULL)".to_string());
            params.push(Box::new(contains_kind.to_string()));
        }
    }

    // Coverage filter WHERE clauses
    if has_coverage {
        if let Some(filter) = coverage_filter {
            match filter {
                CoverageFilter::Uncovered => {
                    where_clauses
                        .push("cov.function_id IS NOT NULL AND cov.covered_blocks = 0".to_string());
                }
                CoverageFilter::Covered => {
                    where_clauses
                        .push("cov.function_id IS NOT NULL AND cov.covered_blocks > 0".to_string());
                }
            }
        }
    }

    // Note: Depth filtering (min_depth, max_depth) is handled post-query
    // due to SQLite recursive CTE limitations in WHERE clauses.
    // See Task 6 for post-query filtering implementation.

    // SymbolSet filter condition
    let symbol_set_strategy = if let Some(symbol_ids) = symbol_set_filter {
        let strategy = symbol_set_filter_strategy(symbol_ids);
        match strategy {
            SymbolSetStrategy::InClause if !symbol_ids.is_empty() => {
                let placeholders = symbol_ids.iter().map(|_| "?").collect::<Vec<_>>().join(",");
                where_clauses.push(format!(
                    "json_extract(s.data, '$.symbol_id') IN ({})",
                    placeholders
                ));
                params.extend(
                    symbol_ids
                        .iter()
                        .map(|id| Box::new(id.clone()) as Box<dyn ToSql>),
                );
            }
            SymbolSetStrategy::TempTable => {
                // Will be handled via JOIN in execution (Plan 11-04)
                where_clauses.push("EXISTS (SELECT 1 FROM symbol_set_filter WHERE symbol_set_filter.symbol_id = json_extract(s.data, '$.symbol_id'))".to_string());
            }
            _ => {}
        }
        strategy
    } else {
        SymbolSetStrategy::None
    };

    let mut select_cols: Vec<&str> = if has_ast_table {
        vec![
            "s.data",
            "f.file_path",
            "sm.fan_in",
            "sm.fan_out",
            "sm.cyclomatic_complexity",
            "json_extract(s.data, '$.symbol_id') AS symbol_id",
            "an.id AS ast_id",
            "an.kind AS ast_kind",
            "an.parent_id AS ast_parent_id",
            "an.byte_start AS ast_byte_start",
            "an.byte_end AS ast_byte_end",
        ]
    } else {
        vec![
            "s.data",
            "f.file_path",
            "sm.fan_in",
            "sm.fan_out",
            "sm.cyclomatic_complexity",
            "json_extract(s.data, '$.symbol_id') AS symbol_id",
        ]
    };

    if has_coverage {
        select_cols.push("cov.total_blocks");
        select_cols.push("cov.covered_blocks");
        select_cols.push("edge_cov.total_edges");
        select_cols.push("edge_cov.covered_edges");
    }

    let select_clause = if count_only {
        "SELECT COUNT(*)".to_string()
    } else {
        format!("SELECT {}", select_cols.join(", "))
    };

    let mut sql = format!(
        "{select_clause}
FROM (
    SELECT id,
           data,
           json_extract(data, '$.name') AS name,
           json_extract(data, '$.display_fqn') AS display_fqn,
           json_extract(data, '$.fqn') AS fqn,
           json_extract(data, '$.canonical_fqn') AS canonical_fqn,
           json_extract(data, '$.kind') AS kind,
           json_extract(data, '$.kind_normalized') AS kind_normalized,
           json_extract(data, '$.start_line') AS start_line,
           json_extract(data, '$.start_col') AS start_col,
           json_extract(data, '$.byte_start') AS byte_start,
           json_extract(data, '$.byte_end') AS byte_end
    FROM graph_entities
    WHERE kind = 'Symbol'
) s
JOIN graph_edges e ON e.to_id = s.id AND e.edge_type = 'DEFINES'
JOIN (
    SELECT id, json_extract(data, '$.path') AS file_path
    FROM graph_entities
    WHERE kind = 'File'
) f ON f.id = e.from_id
LEFT JOIN symbol_metrics sm ON s.id = sm.symbol_id
{ast_join}
{coverage_join}
{edge_coverage_join}
WHERE {where_clause}",
        select_clause = select_clause,
        ast_join = if has_ast_table {
            // Use a correlated subquery to pick exactly one ast_node per symbol byte span.
            // This avoids duplicate rows when multiple AST nodes overlap the same span.
            "LEFT JOIN ast_nodes an ON an.id = (\n            SELECT id FROM ast_nodes\n            WHERE byte_start = json_extract(s.data, '$.byte_start')\n              AND byte_end = json_extract(s.data, '$.byte_end')\n            ORDER BY id LIMIT 1\n        )".to_string()
        } else {
            "".to_string()
        },
        coverage_join = if has_coverage {
            "LEFT JOIN (\n            SELECT b.function_id,\n                   COUNT(b.id) as total_blocks,\n                   COUNT(CASE WHEN COALESCE(bc.hit_count, 0) > 0 THEN 1 END) as covered_blocks\n            FROM cfg_blocks b\n            LEFT JOIN cfg_block_coverage bc ON b.id = bc.block_id\n            GROUP BY b.function_id\n        ) cov ON cov.function_id = s.id".to_string()
        } else {
            "".to_string()
        },
        edge_coverage_join = if has_coverage {
            "LEFT JOIN (\n            SELECT e.function_id,\n                   COUNT(e.id) as total_edges,\n                   COUNT(CASE WHEN COALESCE(ec.hit_count, 0) > 0 THEN 1 END) as covered_edges\n            FROM cfg_edges e\n            LEFT JOIN cfg_edge_coverage ec ON e.id = ec.edge_id\n            GROUP BY e.function_id\n        ) edge_cov ON edge_cov.function_id = s.id".to_string()
        } else {
            "".to_string()
        },
        where_clause = if where_clauses.is_empty() {
            "1=1".to_string()
        } else {
            where_clauses.join(" AND ")
        },
    );

    if !count_only {
        // Determine ORDER BY clause based on sort mode
        let order_by = match sort_by {
            SortMode::FanIn => {
                // Sort by fan_in descending, NULLs last
                "COALESCE(sm.fan_in, 0) DESC, s.start_line, s.start_col, s.byte_start, s.byte_end, s.id"
            }
            SortMode::FanOut => {
                // Sort by fan_out descending, NULLs last
                "COALESCE(sm.fan_out, 0) DESC, s.start_line, s.start_col, s.byte_start, s.byte_end, s.id"
            }
            SortMode::Complexity => {
                // Sort by cyclomatic_complexity descending, NULLs last
                "COALESCE(sm.cyclomatic_complexity, 0) DESC, s.start_line, s.start_col, s.byte_start, s.byte_end, s.id"
            }
            SortMode::AstComplexity => {
                // Sort by AST complexity (cyclomatic_complexity), same as Complexity mode
                "COALESCE(sm.cyclomatic_complexity, 0) DESC, s.start_line, s.start_col, s.byte_start, s.byte_end, s.id"
            }
            SortMode::NestingDepth => {
                // Nesting depth is calculated post-query via batch CTE and sorted in-memory
                "s.start_line, s.start_col, s.byte_start, s.byte_end, s.id"
            }
            SortMode::Position => {
                // Position-based ordering (faster, pure SQL ORDER BY)
                "s.start_line, s.start_col, s.byte_start, s.byte_end, s.id"
            }
            SortMode::Relevance => {
                // Relevance ordering happens in-memory after scoring
                "s.start_line, s.start_col, s.byte_start, s.byte_end, s.id"
            }
        };
        sql.push_str(&format!("\nORDER BY {}\n", order_by));
        sql.push_str("LIMIT ?");
        params.push(Box::new(limit as u64));
    }

    (sql, params, symbol_set_strategy)
}

pub(crate) fn build_reference_query(
    query: &str,
    path_filter: Option<&PathBuf>,
    use_regex: bool,
    count_only: bool,
    limit: usize,
) -> (String, Vec<Box<dyn ToSql>>) {
    let mut params: Vec<Box<dyn ToSql>> = Vec::new();
    let mut where_clauses = vec!["r.kind = 'Reference'".to_string()];

    if !use_regex {
        let like_query = like_pattern(query);
        where_clauses.push("r.name LIKE ? ESCAPE '\\'".to_string());
        params.push(Box::new(like_query));
    }

    if let Some(path) = path_filter {
        where_clauses.push("json_extract(r.data, '$.file') LIKE ? ESCAPE '\\'".to_string());
        params.push(Box::new(like_prefix(path)));
    }

    let select_clause = if count_only {
        "SELECT COUNT(*)"
    } else {
        "SELECT r.data, r.name, json_extract(s.data, '$.symbol_id') AS target_symbol_id"
    };

    let mut sql = format!(
        "{select_clause}
FROM graph_entities r
LEFT JOIN graph_edges e ON e.from_id = r.id AND e.edge_type = 'REFERENCES'
LEFT JOIN graph_entities s ON s.id = e.to_id AND s.kind = 'Symbol'
WHERE {where_clause}",
        select_clause = select_clause,
        where_clause = where_clauses.join(" AND "),
    );

    if !count_only {
        sql.push_str(
            "\nORDER BY json_extract(r.data, '$.start_line'), json_extract(r.data, '$.start_col'), json_extract(r.data, '$.byte_start'), r.id\n",
        );
        sql.push_str("LIMIT ?");
        params.push(Box::new(limit as u64));
    }

    (sql, params)
}

pub(crate) fn build_call_query(
    query: &str,
    path_filter: Option<&PathBuf>,
    use_regex: bool,
    count_only: bool,
    limit: usize,
) -> (String, Vec<Box<dyn ToSql>>) {
    let mut params: Vec<Box<dyn ToSql>> = Vec::new();
    let mut where_clauses = vec!["c.kind = 'Call'".to_string()];

    if !use_regex {
        let like_query = like_pattern(query);
        where_clauses.push(
            "(json_extract(c.data, '$.caller') LIKE ? ESCAPE '\\' OR json_extract(c.data, '$.callee') LIKE ? ESCAPE '\\')"
                .to_string(),
        );
        params.push(Box::new(like_query.clone()));
        params.push(Box::new(like_query));
    }

    if let Some(path) = path_filter {
        where_clauses.push("json_extract(c.data, '$.file') LIKE ? ESCAPE '\\'".to_string());
        params.push(Box::new(like_prefix(path)));
    }

    let select_clause = if count_only {
        "SELECT COUNT(*)"
    } else {
        "SELECT c.data"
    };

    let mut sql = format!(
        "{select_clause}
FROM graph_entities c
WHERE {where_clause}",
        select_clause = select_clause,
        where_clause = where_clauses.join(" AND "),
    );

    if !count_only {
        sql.push_str(
            "\nORDER BY json_extract(c.data, '$.start_line'), json_extract(c.data, '$.start_col'), json_extract(c.data, '$.byte_start'), c.id\n",
        );
        sql.push_str("LIMIT ?");
        params.push(Box::new(limit as u64));
    }

    (sql, params)
}