//! Integration tests for CALL procedure support.
//!
//! Tests CALL statement parsing + execution across GQL, Cypher, and SQL/PGQ.

#![cfg(feature = "algos")]

use grafeo_common::types::Value;
use grafeo_engine::GrafeoDB;

/// Creates 3 Person nodes (Alix, Gus, Harm) with 2 KNOWS edges.
fn setup_graph() -> GrafeoDB {
    let db = GrafeoDB::new_in_memory();
    let alix = db.create_node(&["Person"]);
    let gus = db.create_node(&["Person"]);
    let harm = db.create_node(&["Person"]);

    db.set_node_property(alix, "name", Value::from("Alix"));
    db.set_node_property(gus, "name", Value::from("Gus"));
    db.set_node_property(harm, "name", Value::from("Harm"));

    db.create_edge(alix, gus, "KNOWS");
    db.create_edge(gus, harm, "KNOWS");

    db
}

// ==================== GQL Parser Tests ====================

#[test]
fn test_gql_call_pagerank() {
    let db = setup_graph();
    let session = db.session();
    let result = session.execute("CALL grafeo.pagerank()").unwrap();

    assert_eq!(result.columns.len(), 2);
    assert_eq!(result.columns[0], "node_id");
    assert_eq!(result.columns[1], "score");
    assert_eq!(result.row_count(), 3); // 3 nodes
}

#[test]
fn test_gql_call_pagerank_with_params() {
    let db = setup_graph();
    let session = db.session();
    let result = session
        .execute("CALL grafeo.pagerank({damping: 0.85, max_iterations: 10})")
        .unwrap();

    assert_eq!(result.row_count(), 3);
    // Scores should sum to approximately 1.0
    let total_score: f64 = result
        .rows()
        .iter()
        .map(|row| match &row[1] {
            Value::Float64(f) => *f,
            _ => 0.0,
        })
        .sum();
    assert!(
        (total_score - 1.0).abs() < 0.1,
        "PageRank scores should sum to ~1.0, got {}",
        total_score
    );
}

#[test]
fn test_gql_call_with_yield() {
    let db = setup_graph();
    let session = db.session();
    let result = session
        .execute("CALL grafeo.pagerank() YIELD score")
        .unwrap();

    assert_eq!(result.columns.len(), 1);
    assert_eq!(result.columns[0], "score");
    assert_eq!(result.row_count(), 3);
}

#[test]
fn test_gql_call_with_yield_alias() {
    let db = setup_graph();
    let session = db.session();
    let result = session
        .execute("CALL grafeo.pagerank() YIELD node_id AS id, score AS rank")
        .unwrap();

    assert_eq!(result.columns.len(), 2);
    assert_eq!(result.columns[0], "id");
    assert_eq!(result.columns[1], "rank");
}

#[test]
fn test_gql_call_connected_components() {
    let db = setup_graph();
    let session = db.session();
    let result = session
        .execute("CALL grafeo.connected_components()")
        .unwrap();

    assert_eq!(result.columns.len(), 2);
    assert_eq!(result.columns[0], "node_id");
    assert_eq!(result.columns[1], "component_id");
    assert_eq!(result.row_count(), 3);
    // All 3 nodes should be in the same component (connected graph)
    let components: Vec<&Value> = result.rows().iter().map(|r| &r[1]).collect();
    assert_eq!(components[0], components[1]);
    assert_eq!(components[1], components[2]);
}

#[test]
fn test_gql_call_without_namespace() {
    let db = setup_graph();
    let session = db.session();
    // Should also work without "grafeo." prefix
    let result = session.execute("CALL pagerank()").unwrap();
    assert_eq!(result.row_count(), 3);
}

#[test]
fn test_gql_call_unknown_procedure() {
    let db = setup_graph();
    let session = db.session();
    let result = session.execute("CALL grafeo.nonexistent()");
    assert!(result.is_err());
    let err = result.unwrap_err().to_string();
    assert!(
        err.contains("Unknown procedure"),
        "Expected 'Unknown procedure' error, got: {}",
        err
    );
}

#[test]
fn test_gql_call_procedures_list() {
    let db = setup_graph();
    let session = db.session();
    let result = session.execute("CALL grafeo.procedures()").unwrap();

    assert_eq!(result.columns.len(), 4);
    assert_eq!(result.columns[0], "name");
    assert_eq!(result.columns[1], "description");
    assert!(result.row_count() >= 22, "Expected at least 22 procedures");
}

#[test]
fn test_gql_call_empty_graph() {
    let db = GrafeoDB::new_in_memory();
    let session = db.session();
    let result = session.execute("CALL grafeo.pagerank()").unwrap();
    assert_eq!(result.row_count(), 0);
}

// ==================== Cypher Tests ====================

#[test]
#[cfg(feature = "cypher")]
fn test_cypher_call_pagerank() {
    let db = setup_graph();
    let session = db.session();
    let result = session.execute_cypher("CALL grafeo.pagerank()").unwrap();

    assert_eq!(result.columns.len(), 2);
    assert_eq!(result.columns[0], "node_id");
    assert_eq!(result.columns[1], "score");
    assert_eq!(result.row_count(), 3);
}

#[test]
#[cfg(feature = "cypher")]
fn test_cypher_call_with_yield() {
    let db = setup_graph();
    let session = db.session();
    let result = session
        .execute_cypher("CALL grafeo.pagerank() YIELD score")
        .unwrap();

    assert_eq!(result.columns.len(), 1);
    assert_eq!(result.columns[0], "score");
}

#[test]
#[cfg(feature = "cypher")]
fn test_cypher_call_connected_components() {
    let db = setup_graph();
    let session = db.session();
    let result = session
        .execute_cypher("CALL grafeo.connected_components()")
        .unwrap();

    assert_eq!(result.row_count(), 3);
}

// ==================== SQL/PGQ Tests ====================

#[test]
#[cfg(feature = "sql-pgq")]
fn test_sql_pgq_call_pagerank() {
    let db = setup_graph();
    let session = db.session();
    let result = session.execute_sql("CALL grafeo.pagerank()").unwrap();

    assert_eq!(result.columns.len(), 2);
    assert_eq!(result.columns[0], "node_id");
    assert_eq!(result.columns[1], "score");
    assert_eq!(result.row_count(), 3);
}

#[test]
#[cfg(feature = "sql-pgq")]
fn test_sql_pgq_call_with_yield() {
    let db = setup_graph();
    let session = db.session();
    let result = session
        .execute_sql("CALL grafeo.pagerank() YIELD score AS rank")
        .unwrap();

    assert_eq!(result.columns.len(), 1);
    assert_eq!(result.columns[0], "rank");
}

// ==================== Language Parity Tests ====================

#[test]
#[cfg(all(feature = "cypher", feature = "sql-pgq"))]
fn test_language_parity_pagerank() {
    let db = setup_graph();
    let session = db.session();

    let gql_result = session.execute("CALL grafeo.pagerank()").unwrap();
    let cypher_result = session.execute_cypher("CALL grafeo.pagerank()").unwrap();
    let sql_result = session.execute_sql("CALL grafeo.pagerank()").unwrap();

    // All three should return same row count and column names
    assert_eq!(gql_result.columns, cypher_result.columns);
    assert_eq!(gql_result.columns, sql_result.columns);
    assert_eq!(gql_result.row_count(), cypher_result.row_count());
    assert_eq!(gql_result.row_count(), sql_result.row_count());
}

// ==================== Algorithm-Specific Tests ====================

#[test]
fn test_call_bfs() {
    let db = setup_graph();
    let session = db.session();
    // BFS from node 0 (first created node)
    let result = session.execute("CALL grafeo.bfs(0)").unwrap();

    assert_eq!(result.columns.len(), 2);
    assert_eq!(result.columns[0], "node_id");
    assert_eq!(result.columns[1], "depth");
    // Should reach all 3 nodes from node 0
    assert!(result.row_count() >= 1);
}

#[test]
fn test_call_clustering_coefficient() {
    let db = setup_graph();
    let session = db.session();
    let result = session
        .execute("CALL grafeo.clustering_coefficient()")
        .unwrap();

    assert_eq!(result.columns[0], "node_id");
    assert_eq!(result.columns[1], "coefficient");
    assert_eq!(result.columns[2], "triangle_count");
    assert_eq!(result.row_count(), 3);

    // Coefficients should be in [0.0, 1.0]
    for row in result.rows() {
        if let Value::Float64(coeff) = &row[1] {
            assert!(
                (0.0..=1.0).contains(coeff),
                "Coefficient {} out of range",
                coeff
            );
        }
    }
}

#[test]
fn test_call_degree_centrality() {
    let db = setup_graph();
    let session = db.session();
    let result = session.execute("CALL grafeo.degree_centrality()").unwrap();

    assert_eq!(result.columns[0], "node_id");
    assert_eq!(result.columns[1], "in_degree");
    assert_eq!(result.columns[2], "out_degree");
    assert_eq!(result.columns[3], "total_degree");
    assert_eq!(result.row_count(), 3);
}

// ==================== Case Insensitivity ====================

#[test]
fn test_call_case_insensitive() {
    let db = setup_graph();
    let session = db.session();

    // CALL keyword should be case-insensitive (handled by lexer)
    // The procedure name is case-sensitive (matched against algorithm names)
    let result = session.execute("CALL grafeo.pagerank()");
    assert!(result.is_ok());
}

// ==================== Edge Cases & Error Paths ====================

#[test]
fn test_call_yield_nonexistent_column() {
    let db = setup_graph();
    let session = db.session();
    let result = session.execute("CALL grafeo.pagerank() YIELD nonexistent_column");
    assert!(result.is_err(), "YIELD of nonexistent column should fail");
    let err = result.unwrap_err().to_string();
    assert!(
        err.contains("not found"),
        "Error should mention column not found, got: {}",
        err
    );
}

#[test]
fn test_call_yield_duplicate_columns() {
    let db = setup_graph();
    let session = db.session();
    // YIELD same column twice with different aliases should work
    let result = session.execute("CALL grafeo.pagerank() YIELD score AS s1, score AS s2");
    assert!(
        result.is_ok(),
        "YIELD same column with different aliases should work: {:?}",
        result.err()
    );
    let result = result.unwrap();
    assert_eq!(result.columns.len(), 2);
    assert_eq!(result.columns[0], "s1");
    assert_eq!(result.columns[1], "s2");
}

#[test]
fn test_call_procedures_list_has_expected_columns() {
    let db = setup_graph();
    let session = db.session();
    let result = session.execute("CALL grafeo.procedures()").unwrap();

    assert_eq!(result.columns[0], "name");
    assert_eq!(result.columns[1], "description");
    assert_eq!(result.columns[2], "parameters");
    assert_eq!(result.columns[3], "output_columns");

    // Every procedure should have a non-empty name
    for row in result.rows() {
        if let Value::String(name) = &row[0] {
            assert!(!name.is_empty(), "Procedure name should not be empty");
        } else {
            panic!("Procedure name should be a string");
        }
    }
}

#[test]
fn test_call_multiple_algorithms_on_same_graph() {
    let db = setup_graph();
    let session = db.session();

    // Run several algorithms on the same graph to test they don't interfere
    let pr = session.execute("CALL grafeo.pagerank()").unwrap();
    let cc = session
        .execute("CALL grafeo.connected_components()")
        .unwrap();
    let dc = session.execute("CALL grafeo.degree_centrality()").unwrap();
    let bc = session
        .execute("CALL grafeo.betweenness_centrality()")
        .unwrap();

    assert_eq!(pr.row_count(), 3);
    assert_eq!(cc.row_count(), 3);
    assert_eq!(dc.row_count(), 3);
    assert_eq!(bc.row_count(), 3);
}

#[test]
fn test_call_bfs_with_invalid_source() {
    let db = setup_graph();
    let session = db.session();
    // BFS from a non-existent node
    let result = session.execute("CALL grafeo.bfs(999999)");
    // Should either return empty results or an error, not panic
    match result {
        Ok(r) => assert_eq!(
            r.row_count(),
            0,
            "BFS from invalid source should return empty"
        ),
        Err(_) => {} // error is acceptable too
    }
}

#[test]
fn test_call_shortest_path_disconnected() {
    let db = GrafeoDB::new_in_memory();
    // Create two disconnected components
    let a = db.create_node(&["Node"]);
    let b = db.create_node(&["Node"]);
    db.set_node_property(a, "name", Value::from("A"));
    db.set_node_property(b, "name", Value::from("B"));
    // No edge between them

    let session = db.session();
    let result = session.execute(&format!(
        "CALL grafeo.shortest_path({}, {})",
        a.as_u64(),
        b.as_u64()
    ));
    // Should return empty (no path), not panic
    match result {
        Ok(r) => assert_eq!(r.row_count(), 0, "No path between disconnected nodes"),
        Err(_) => {} // error is also acceptable
    }
}

#[test]
fn test_call_pagerank_single_node() {
    let db = GrafeoDB::new_in_memory();
    db.create_node(&["Isolated"]);

    let session = db.session();
    let result = session.execute("CALL grafeo.pagerank()").unwrap();
    assert_eq!(result.row_count(), 1, "Single node should get PageRank");
    if let Value::Float64(score) = &result.rows()[0][1] {
        assert!(
            (*score - 1.0).abs() < 0.01,
            "Single node should have PageRank ~1.0, got {}",
            score
        );
    }
}

#[test]
fn test_call_yield_all_then_specific() {
    let db = setup_graph();
    let session = db.session();

    // First call without YIELD (get all columns)
    let all = session.execute("CALL grafeo.pagerank()").unwrap();
    // Then call with specific YIELD
    let specific = session
        .execute("CALL grafeo.pagerank() YIELD score")
        .unwrap();

    assert_eq!(
        all.columns.len(),
        2,
        "Without YIELD: should get all columns"
    );
    assert_eq!(specific.columns.len(), 1, "With YIELD: should get 1 column");
    assert_eq!(
        all.row_count(),
        specific.row_count(),
        "Row counts should match"
    );
}

// ==================== Phase 2: YIELD + WHERE + RETURN ====================

#[test]
fn test_gql_call_yield_where() {
    let db = setup_graph();
    let session = db.session();
    // Filter PageRank scores > 0 (all should pass since every node has a score)
    let result = session
        .execute("CALL grafeo.pagerank() YIELD node_id, score WHERE score > 0.0")
        .unwrap();

    assert_eq!(result.columns.len(), 2);
    assert_eq!(result.row_count(), 3);

    // Verify all scores are positive
    for row in result.rows() {
        if let Value::Float64(score) = &row[1] {
            assert!(*score > 0.0, "Expected score > 0.0, got {}", score);
        }
    }
}

#[test]
fn test_gql_call_yield_where_filters_rows() {
    let db = setup_graph();
    let session = db.session();
    // Use a high threshold that eliminates some results
    let all = session.execute("CALL grafeo.pagerank()").unwrap();
    let max_score = all
        .rows()
        .iter()
        .map(|r| match &r[1] {
            Value::Float64(f) => *f,
            _ => 0.0,
        })
        .fold(f64::NEG_INFINITY, f64::max);

    // Filter for score > max_score should return 0 rows
    let result = session
        .execute(&format!(
            "CALL grafeo.pagerank() YIELD score WHERE score > {}",
            max_score
        ))
        .unwrap();
    assert_eq!(result.row_count(), 0, "No score should exceed the maximum");
}

#[test]
fn test_gql_call_yield_return() {
    let db = setup_graph();
    let session = db.session();
    let result = session
        .execute("CALL grafeo.pagerank() YIELD node_id, score RETURN node_id, score")
        .unwrap();

    assert_eq!(result.columns.len(), 2);
    assert_eq!(result.columns[0], "node_id");
    assert_eq!(result.columns[1], "score");
    assert_eq!(result.row_count(), 3);
}

#[test]
fn test_gql_call_yield_return_with_alias() {
    let db = setup_graph();
    let session = db.session();
    let result = session
        .execute("CALL grafeo.pagerank() YIELD node_id, score RETURN node_id AS id, score AS rank")
        .unwrap();

    assert_eq!(result.columns.len(), 2);
    assert_eq!(result.columns[0], "id");
    assert_eq!(result.columns[1], "rank");
}

#[test]
fn test_gql_call_yield_return_order_by() {
    let db = setup_graph();
    let session = db.session();
    let result = session
        .execute(
            "CALL grafeo.pagerank() YIELD node_id, score RETURN node_id, score ORDER BY score DESC",
        )
        .unwrap();

    assert_eq!(result.row_count(), 3);
    // Verify descending order
    let scores: Vec<f64> = result
        .rows()
        .iter()
        .map(|r| match &r[1] {
            Value::Float64(f) => *f,
            _ => 0.0,
        })
        .collect();
    for i in 1..scores.len() {
        assert!(
            scores[i - 1] >= scores[i],
            "Scores should be in DESC order: {:?}",
            scores
        );
    }
}

#[test]
fn test_gql_call_yield_return_limit() {
    let db = setup_graph();
    let session = db.session();
    let result = session
        .execute("CALL grafeo.pagerank() YIELD node_id, score RETURN node_id, score LIMIT 2")
        .unwrap();

    assert_eq!(result.row_count(), 2);
}

#[test]
fn test_gql_call_yield_where_return_order_limit() {
    let db = setup_graph();
    let session = db.session();
    // Full pipeline: YIELD → WHERE → RETURN with ORDER BY + LIMIT
    let result = session
        .execute(
            "CALL grafeo.pagerank() YIELD node_id, score \
             WHERE score > 0.0 \
             RETURN node_id, score ORDER BY score DESC LIMIT 2",
        )
        .unwrap();

    assert!(
        result.row_count() <= 2,
        "LIMIT 2 should return at most 2 rows"
    );
    // Verify descending order
    if result.row_count() == 2 {
        let s0 = match &result.rows()[0][1] {
            Value::Float64(f) => *f,
            _ => 0.0,
        };
        let s1 = match &result.rows()[1][1] {
            Value::Float64(f) => *f,
            _ => 0.0,
        };
        assert!(
            s0 >= s1,
            "First score {} should be >= second score {}",
            s0,
            s1
        );
    }
}

#[test]
fn test_gql_call_yield_return_skip() {
    let db = setup_graph();
    let session = db.session();
    let result = session
        .execute("CALL grafeo.pagerank() YIELD node_id, score RETURN node_id, score SKIP 1")
        .unwrap();

    assert_eq!(result.row_count(), 2, "SKIP 1 of 3 rows should leave 2");
}

#[test]
fn test_gql_call_yield_return_order_skip_limit() {
    let db = setup_graph();
    let session = db.session();
    let result = session
        .execute(
            "CALL grafeo.pagerank() YIELD node_id, score \
             RETURN node_id, score ORDER BY score DESC SKIP 1 LIMIT 1",
        )
        .unwrap();

    assert_eq!(result.row_count(), 1, "SKIP 1 + LIMIT 1 should leave 1 row");
}

// ==================== Phase 2: SQL/PGQ WHERE + ORDER BY + LIMIT ====================

#[test]
#[cfg(feature = "sql-pgq")]
fn test_sql_pgq_call_yield_where() {
    let db = setup_graph();
    let session = db.session();
    let result = session
        .execute_sql("CALL grafeo.pagerank() YIELD node_id, score WHERE score > 0.0")
        .unwrap();

    assert_eq!(result.columns.len(), 2);
    assert_eq!(result.row_count(), 3);
}

#[test]
#[cfg(feature = "sql-pgq")]
fn test_sql_pgq_call_yield_order_by_limit() {
    let db = setup_graph();
    let session = db.session();
    let result = session
        .execute_sql("CALL grafeo.pagerank() YIELD node_id, score ORDER BY score DESC LIMIT 2")
        .unwrap();

    assert!(result.row_count() <= 2);
    // Verify descending order
    if result.row_count() == 2 {
        let s0 = match &result.rows()[0][1] {
            Value::Float64(f) => *f,
            _ => 0.0,
        };
        let s1 = match &result.rows()[1][1] {
            Value::Float64(f) => *f,
            _ => 0.0,
        };
        assert!(s0 >= s1, "Scores should be in DESC order");
    }
}

#[test]
#[cfg(feature = "sql-pgq")]
fn test_sql_pgq_call_yield_where_order_limit() {
    let db = setup_graph();
    let session = db.session();
    let result = session
        .execute_sql(
            "CALL grafeo.pagerank() YIELD node_id, score \
             WHERE score > 0.0 ORDER BY score DESC LIMIT 2",
        )
        .unwrap();

    assert!(result.row_count() <= 2);
}

// ==================== Phase 2: SQL/PGQ SKIP + ORDER ASC ====================

#[test]
#[cfg(feature = "sql-pgq")]
fn test_sql_pgq_call_yield_where_return_skip_limit() {
    let db = setup_graph();
    let session = db.session();
    // Full chain: WHERE + ORDER BY + LIMIT (exercises all SQL/PGQ translator branches)
    let result = session
        .execute_sql(
            "CALL grafeo.pagerank() YIELD node_id, score \
             WHERE score > 0.0 ORDER BY score ASC LIMIT 1",
        )
        .unwrap();

    assert_eq!(result.row_count(), 1);
    // Verify it's the smallest score (ASC order, LIMIT 1)
    let all = session
        .execute_sql("CALL grafeo.pagerank() YIELD score ORDER BY score ASC")
        .unwrap();
    assert_eq!(result.rows()[0][1], all.rows()[0][0]);
}

// ==================== Phase 2: GQL ORDER ASC + RETURN DISTINCT ====================

#[test]
fn test_gql_call_yield_return_order_asc() {
    let db = setup_graph();
    let session = db.session();
    let result = session
        .execute(
            "CALL grafeo.pagerank() YIELD node_id, score \
             RETURN node_id, score ORDER BY score ASC",
        )
        .unwrap();

    assert_eq!(result.row_count(), 3);
    let scores: Vec<f64> = result
        .rows()
        .iter()
        .map(|r| match &r[1] {
            Value::Float64(f) => *f,
            _ => 0.0,
        })
        .collect();
    for i in 1..scores.len() {
        assert!(
            scores[i - 1] <= scores[i],
            "Scores should be in ASC order: {:?}",
            scores
        );
    }
}

#[test]
fn test_gql_call_yield_return_distinct() {
    let db = setup_graph();
    let session = db.session();
    // RETURN DISTINCT should deduplicate rows
    let all = session
        .execute(
            "CALL grafeo.connected_components() YIELD component_id \
             RETURN component_id",
        )
        .unwrap();
    let distinct = session
        .execute(
            "CALL grafeo.connected_components() YIELD component_id \
             RETURN DISTINCT component_id",
        )
        .unwrap();

    // DISTINCT should return <= the original row count
    assert!(
        distinct.row_count() <= all.row_count(),
        "DISTINCT ({}) should not exceed original ({})",
        distinct.row_count(),
        all.row_count()
    );
}

// ==================== Phase 2: Cypher WHERE + RETURN (clause-based) ====================

#[test]
#[cfg(feature = "cypher")]
fn test_cypher_call_yield_where_return() {
    let db = setup_graph();
    let session = db.session();
    let result = session
        .execute_cypher(
            "CALL grafeo.pagerank() YIELD node_id, score \
             WHERE score > 0.0 \
             RETURN node_id, score ORDER BY score DESC LIMIT 2",
        )
        .unwrap();

    assert!(result.row_count() <= 2);
}
