use super::*;
use crate::core::db::{create_connection, run_migrations};
use std::path::Path;

fn setup_test_db() -> Connection {
    let conn = create_connection(Path::new(":memory:")).unwrap();
    run_migrations(&conn).unwrap();
    conn
}

fn seed_project(conn: &Connection, id: i64) {
    conn.execute(
        "INSERT INTO projects (id, gitlab_project_id, path_with_namespace, web_url, created_at, updated_at)
         VALUES (?1, ?1, 'group/repo', 'https://gl.example.com/group/repo', 1000, 2000)",
        rusqlite::params![id],
    )
    .unwrap();
}

fn seed_mr(conn: &Connection, mr_id: i64, project_id: i64) {
    conn.execute(
        "INSERT INTO merge_requests (id, gitlab_id, iid, project_id, title, state, \
         created_at, updated_at, last_seen_at, source_branch, target_branch)
         VALUES (?1, ?1, ?1, ?2, 'MR', 'merged', 1000, 2000, 2000, 'feat', 'main')",
        rusqlite::params![mr_id, project_id],
    )
    .unwrap();
}

fn seed_file_change(conn: &Connection, mr_id: i64, project_id: i64, path: &str) {
    conn.execute(
        "INSERT INTO mr_file_changes (merge_request_id, project_id, new_path, change_type)
         VALUES (?1, ?2, ?3, 'modified')",
        rusqlite::params![mr_id, project_id, path],
    )
    .unwrap();
}

fn seed_diffnote(conn: &Connection, id: i64, project_id: i64, path: &str) {
    // Need a discussion first (MergeRequest type, linked to mr_id=1)
    conn.execute(
        "INSERT OR IGNORE INTO discussions (id, gitlab_discussion_id, project_id, \
         merge_request_id, noteable_type, resolvable, resolved, last_seen_at, last_note_at)
         VALUES (?1, ?2, ?3, 1, 'MergeRequest', 1, 0, 2000, 2000)",
        rusqlite::params![id, format!("disc-{id}"), project_id],
    )
    .unwrap();
    conn.execute(
        "INSERT INTO notes (id, gitlab_id, discussion_id, project_id, note_type, is_system, \
         author_username, body, created_at, updated_at, last_seen_at, position_new_path)
         VALUES (?1, ?1, ?1, ?2, 'DiffNote', 0, 'user', 'note', 1000, 2000, 2000, ?3)",
        rusqlite::params![id, project_id, path],
    )
    .unwrap();
}

// ─── escape_like ─────────────────────────────────────────────────────────────

#[test]
fn test_escape_like() {
    assert_eq!(escape_like("normal/path"), "normal/path");
    assert_eq!(escape_like("has_underscore"), "has\\_underscore");
    assert_eq!(escape_like("has%percent"), "has\\%percent");
    assert_eq!(escape_like("has\\backslash"), "has\\\\backslash");
}

// ─── normalize_repo_path ─────────────────────────────────────────────────────

#[test]
fn test_normalize_repo_path() {
    assert_eq!(normalize_repo_path("./src/foo/"), "src/foo/");
    assert_eq!(normalize_repo_path("/src/foo/"), "src/foo/");
    assert_eq!(normalize_repo_path("././src/foo"), "src/foo");
    assert_eq!(normalize_repo_path("src\\foo\\bar.rs"), "src/foo/bar.rs");
    assert_eq!(normalize_repo_path("src/foo\\bar"), "src/foo\\bar");
    assert_eq!(normalize_repo_path("src//foo//bar/"), "src/foo/bar/");
    assert_eq!(normalize_repo_path("  src/foo/  "), "src/foo/");
    assert_eq!(normalize_repo_path("src/foo/bar.rs"), "src/foo/bar.rs");
    assert_eq!(normalize_repo_path(""), "");
}

// ─── build_path_query heuristics (no DB data) ──────────────────────────────

#[test]
fn test_trailing_slash_is_prefix() {
    let conn = setup_test_db();
    let pq = build_path_query(&conn, "src/auth/", None).unwrap();
    assert_eq!(pq.value, "src/auth/%");
    assert!(pq.is_prefix);
}

#[test]
fn test_no_dot_in_last_segment_is_prefix() {
    let conn = setup_test_db();
    let pq = build_path_query(&conn, "src/auth", None).unwrap();
    assert_eq!(pq.value, "src/auth/%");
    assert!(pq.is_prefix);
}

#[test]
fn test_file_extension_is_exact() {
    let conn = setup_test_db();
    let pq = build_path_query(&conn, "src/auth/login.rs", None).unwrap();
    assert_eq!(pq.value, "src/auth/login.rs");
    assert!(!pq.is_prefix);
}

#[test]
fn test_root_file_is_exact() {
    let conn = setup_test_db();
    let pq = build_path_query(&conn, "README.md", None).unwrap();
    assert_eq!(pq.value, "README.md");
    assert!(!pq.is_prefix);
}

#[test]
fn test_dotless_root_file_is_exact() {
    let conn = setup_test_db();
    let pq = build_path_query(&conn, "Makefile", None).unwrap();
    assert_eq!(pq.value, "Makefile");
    assert!(!pq.is_prefix);

    let pq = build_path_query(&conn, "LICENSE", None).unwrap();
    assert_eq!(pq.value, "LICENSE");
    assert!(!pq.is_prefix);
}

#[test]
fn test_metacharacters_escaped_in_prefix() {
    let conn = setup_test_db();
    let pq = build_path_query(&conn, "src/test_files/", None).unwrap();
    assert_eq!(pq.value, "src/test\\_files/%");
    assert!(pq.is_prefix);
}

#[test]
fn test_exact_value_not_escaped() {
    let conn = setup_test_db();
    let pq = build_path_query(&conn, "README_with_underscore.md", None).unwrap();
    assert_eq!(pq.value, "README_with_underscore.md");
    assert!(!pq.is_prefix);
}

// ─── build_path_query DB probes ─────────────────────────────────────────────

#[test]
fn test_db_probe_detects_dotless_file() {
    // "src/Dockerfile" has no dot in last segment -> normally prefix.
    // DB probe detects it's actually a file.
    let conn = setup_test_db();
    seed_project(&conn, 1);
    seed_mr(&conn, 1, 1);
    seed_diffnote(&conn, 1, 1, "src/Dockerfile");

    let pq = build_path_query(&conn, "src/Dockerfile", None).unwrap();
    assert_eq!(pq.value, "src/Dockerfile");
    assert!(!pq.is_prefix);

    // Without DB data -> falls through to prefix
    let empty = setup_test_db();
    let pq2 = build_path_query(&empty, "src/Dockerfile", None).unwrap();
    assert!(pq2.is_prefix);
}

#[test]
fn test_db_probe_via_file_changes() {
    // Exact match via mr_file_changes even without notes
    let conn = setup_test_db();
    seed_project(&conn, 1);
    seed_mr(&conn, 1, 1);
    seed_file_change(&conn, 1, 1, "src/Dockerfile");

    let pq = build_path_query(&conn, "src/Dockerfile", None).unwrap();
    assert_eq!(pq.value, "src/Dockerfile");
    assert!(!pq.is_prefix);
}

#[test]
fn test_db_probe_project_scoped() {
    let conn = setup_test_db();
    seed_project(&conn, 1);
    seed_project(&conn, 2);
    seed_mr(&conn, 1, 1);
    seed_diffnote(&conn, 1, 1, "infra/Makefile");

    // Unscoped: finds it
    assert!(
        !build_path_query(&conn, "infra/Makefile", None)
            .unwrap()
            .is_prefix
    );
    // Scoped to project 1: finds it
    assert!(
        !build_path_query(&conn, "infra/Makefile", Some(1))
            .unwrap()
            .is_prefix
    );
    // Scoped to project 2: no data -> prefix
    assert!(
        build_path_query(&conn, "infra/Makefile", Some(2))
            .unwrap()
            .is_prefix
    );
}

// ─── suffix resolution ──────────────────────────────────────────────────────

#[test]
fn test_suffix_resolves_bare_filename() {
    let conn = setup_test_db();
    seed_project(&conn, 1);
    seed_mr(&conn, 1, 1);
    seed_file_change(&conn, 1, 1, "src/auth/login.rs");

    let pq = build_path_query(&conn, "login.rs", None).unwrap();
    assert_eq!(pq.value, "src/auth/login.rs");
    assert!(!pq.is_prefix);
}

#[test]
fn test_suffix_resolves_partial_path() {
    let conn = setup_test_db();
    seed_project(&conn, 1);
    seed_mr(&conn, 1, 1);
    seed_file_change(&conn, 1, 1, "src/auth/login.rs");

    let pq = build_path_query(&conn, "auth/login.rs", None).unwrap();
    assert_eq!(pq.value, "src/auth/login.rs");
    assert!(!pq.is_prefix);
}

#[test]
fn test_suffix_ambiguous_returns_error() {
    let conn = setup_test_db();
    seed_project(&conn, 1);
    seed_mr(&conn, 1, 1);
    seed_file_change(&conn, 1, 1, "src/auth/utils.rs");
    seed_file_change(&conn, 1, 1, "src/db/utils.rs");

    let err = build_path_query(&conn, "utils.rs", None).unwrap_err();
    let msg = err.to_string();
    assert!(msg.contains("src/auth/utils.rs"), "candidates: {msg}");
    assert!(msg.contains("src/db/utils.rs"), "candidates: {msg}");
}

#[test]
fn test_suffix_scoped_to_project() {
    let conn = setup_test_db();
    seed_project(&conn, 1);
    seed_project(&conn, 2);
    seed_mr(&conn, 1, 1);
    seed_mr(&conn, 2, 2);
    seed_file_change(&conn, 1, 1, "src/utils.rs");
    seed_file_change(&conn, 2, 2, "lib/utils.rs");

    // Unscoped: ambiguous
    assert!(build_path_query(&conn, "utils.rs", None).is_err());

    // Scoped to project 1: resolves
    let pq = build_path_query(&conn, "utils.rs", Some(1)).unwrap();
    assert_eq!(pq.value, "src/utils.rs");
}

#[test]
fn test_suffix_deduplicates_across_sources() {
    // Same path in notes AND file_changes -> single match, not ambiguous
    let conn = setup_test_db();
    seed_project(&conn, 1);
    seed_mr(&conn, 1, 1);
    seed_file_change(&conn, 1, 1, "src/auth/login.rs");
    seed_diffnote(&conn, 1, 1, "src/auth/login.rs");

    let pq = build_path_query(&conn, "login.rs", None).unwrap();
    assert_eq!(pq.value, "src/auth/login.rs");
    assert!(!pq.is_prefix);
}

#[test]
fn test_exact_match_preferred_over_suffix() {
    let conn = setup_test_db();
    seed_project(&conn, 1);
    seed_mr(&conn, 1, 1);
    seed_file_change(&conn, 1, 1, "README.md");
    seed_file_change(&conn, 1, 1, "docs/README.md");

    // "README.md" exists as exact match -> no ambiguity
    let pq = build_path_query(&conn, "README.md", None).unwrap();
    assert_eq!(pq.value, "README.md");
    assert!(!pq.is_prefix);
}

fn seed_rename(conn: &Connection, mr_id: i64, project_id: i64, old_path: &str, new_path: &str) {
    conn.execute(
        "INSERT INTO mr_file_changes (merge_request_id, project_id, old_path, new_path, change_type)
         VALUES (?1, ?2, ?3, ?4, 'renamed')",
        rusqlite::params![mr_id, project_id, old_path, new_path],
    )
    .unwrap();
}

// ─── rename-aware ambiguity resolution ──────────────────────────────────────

#[test]
fn test_ambiguity_resolved_by_rename_chain() {
    let conn = setup_test_db();
    seed_project(&conn, 1);
    seed_mr(&conn, 1, 1);
    seed_mr(&conn, 2, 1);

    // File was at src/old/operators.ts, then renamed to src/new/operators.ts
    seed_file_change(&conn, 1, 1, "src/old/operators.ts");
    seed_rename(&conn, 2, 1, "src/old/operators.ts", "src/new/operators.ts");

    // Bare "operators.ts" matches both paths via suffix probe, but they're
    // connected by a rename — should auto-resolve to the newest path.
    let pq = build_path_query(&conn, "operators.ts", Some(1)).unwrap();
    assert_eq!(pq.value, "src/new/operators.ts");
    assert!(!pq.is_prefix);
}

#[test]
fn test_ambiguity_not_resolved_when_genuinely_different_files() {
    let conn = setup_test_db();
    seed_project(&conn, 1);
    seed_mr(&conn, 1, 1);

    // Two genuinely different files with the same name (no rename connecting them)
    seed_file_change(&conn, 1, 1, "src/utils/helpers.ts");
    seed_file_change(&conn, 1, 1, "tests/utils/helpers.ts");

    let err = build_path_query(&conn, "helpers.ts", Some(1)).unwrap_err();
    assert!(err.to_string().contains("matches multiple paths"));
}

#[test]
fn test_ambiguity_rename_chain_with_three_hops() {
    let conn = setup_test_db();
    seed_project(&conn, 1);
    seed_mr(&conn, 1, 1);
    seed_mr(&conn, 2, 1);
    seed_mr(&conn, 3, 1);

    // File named "config.ts" moved twice: lib/ -> src/ -> src/core/
    seed_file_change(&conn, 1, 1, "lib/config.ts");
    seed_rename(&conn, 2, 1, "lib/config.ts", "src/config.ts");
    seed_rename(&conn, 3, 1, "src/config.ts", "src/core/config.ts");

    // "config.ts" matches lib/config.ts, src/config.ts, src/core/config.ts via suffix
    let pq = build_path_query(&conn, "config.ts", Some(1)).unwrap();
    assert_eq!(pq.value, "src/core/config.ts");
    assert!(!pq.is_prefix);
}

#[test]
fn test_ambiguity_rename_without_project_id_stays_ambiguous() {
    let conn = setup_test_db();
    seed_project(&conn, 1);
    seed_mr(&conn, 1, 1);
    seed_mr(&conn, 2, 1);

    seed_file_change(&conn, 1, 1, "src/old/utils.ts");
    seed_rename(&conn, 2, 1, "src/old/utils.ts", "src/new/utils.ts");

    // Without project_id, rename resolution is skipped → stays ambiguous
    let err = build_path_query(&conn, "utils.ts", None).unwrap_err();
    assert!(err.to_string().contains("matches multiple paths"));
}