//! Tests for the CRDT write module — migrations, item writes, and setters.

use super::super::hex;
use super::super::read::{extract_item_view, read_item};
use super::super::state::{init_for_test, rebuild_index};
use super::super::types::PipelineDoc;
use super::migrations::numeric_id_from_slug;
use super::*;
use bft_json_crdt::json_crdt::{BaseCrdt, JsonValue, SignedOp};
use bft_json_crdt::keypair::make_keypair;
use bft_json_crdt::op::ROOT_ID;
use serde_json::json;
use sqlx::SqlitePool;
use sqlx::sqlite::SqliteConnectOptions;

// ── name_from_story_id tests ─────────────────────────────────────────────

#[test]
fn name_from_story_id_story_type() {
    assert_eq!(
        name_from_story_id("729_story_store_story_name_as_a_crdt_field"),
        "Store story name as a crdt field"
    );
}

#[test]
fn name_from_story_id_bug_type() {
    assert_eq!(name_from_story_id("4_bug_login_crash"), "Login crash");
}

#[test]
fn name_from_story_id_spike_type() {
    assert_eq!(name_from_story_id("10_spike_arch_review"), "Arch review");
}

#[test]
fn name_from_story_id_refactor_type() {
    assert_eq!(
        name_from_story_id("99_refactor_decompose_server"),
        "Decompose server"
    );
}

#[test]
fn name_from_story_id_single_word() {
    assert_eq!(name_from_story_id("1_story_auth"), "Auth");
}

#[test]
fn name_from_story_id_unknown_type_fallback() {
    // Unknown type prefix is left as-is after stripping the number.
    assert_eq!(name_from_story_id("5_unknown_foo_bar"), "Unknown foo bar");
}

// ── numeric_id_from_slug tests ────────────────────────────────────────────

#[test]
fn numeric_id_from_slug_extracts_prefix() {
    assert_eq!(
        numeric_id_from_slug("664_story_my_feature"),
        Some("664".to_string())
    );
    assert_eq!(
        numeric_id_from_slug("4_bug_login_crash"),
        Some("4".to_string())
    );
    assert_eq!(
        numeric_id_from_slug("730_refactor_foo_bar"),
        Some("730".to_string())
    );
}

#[test]
fn numeric_id_from_slug_returns_none_for_numeric_only() {
    assert_eq!(numeric_id_from_slug("664"), None);
    assert_eq!(numeric_id_from_slug("1"), None);
    assert_eq!(numeric_id_from_slug("730"), None);
}

#[test]
fn numeric_id_from_slug_returns_none_for_non_numeric_prefix() {
    assert_eq!(numeric_id_from_slug("story_no_number"), None);
    assert_eq!(numeric_id_from_slug(""), None);
    assert_eq!(numeric_id_from_slug("abc_story"), None);
}

// ── migrate_story_ids_to_numeric tests ───────────────────────────────────

#[test]
fn migrate_story_ids_to_numeric_rewrites_slug_ids() {
    init_for_test();

    write_item(
        "42_story_my_feature",
        "1_backlog",
        Some("My Feature"),
        None,
        None,
        None,
        None,
        None,
        None,
        None,
    );

    let result = migrate_story_ids_to_numeric();
    assert_eq!(result.len(), 1, "exactly one item should be migrated");
    assert_eq!(result[0].0, "42_story_my_feature");
    assert_eq!(result[0].1, "42");

    // After migration the item is accessible by the numeric ID.
    let item = read_item("42").expect("item should be found by numeric ID");
    assert_eq!(item.story_id, "42");

    // The slug-based ID is gone.
    assert!(
        read_item("42_story_my_feature").is_none(),
        "slug ID should no longer be in the index"
    );
}

#[test]
fn migrate_story_ids_to_numeric_is_idempotent() {
    init_for_test();

    write_item(
        "43",
        "1_backlog",
        Some("Already Numeric"),
        None,
        None,
        None,
        None,
        None,
        None,
        None,
    );

    // First call — nothing to migrate.
    let r1 = migrate_story_ids_to_numeric();
    assert!(r1.is_empty(), "no migration for already-numeric ID");

    // Second call — still nothing.
    let r2 = migrate_story_ids_to_numeric();
    assert!(r2.is_empty(), "second call must be a no-op");

    // Item is still there.
    assert!(read_item("43").is_some());
}

#[test]
fn migrate_story_ids_to_numeric_skips_conflict() {
    init_for_test();

    // Both the slug form AND its numeric target exist.
    write_item(
        "44_story_foo",
        "1_backlog",
        None,
        None,
        None,
        None,
        None,
        None,
        None,
        None,
    );
    write_item(
        "44",
        "2_current",
        None,
        None,
        None,
        None,
        None,
        None,
        None,
        None,
    );

    let result = migrate_story_ids_to_numeric();
    // The slug entry must NOT be migrated because "44" is already occupied.
    assert!(
        result.is_empty(),
        "conflicting slug must not overwrite existing numeric entry"
    );

    // Both items remain as they were.
    assert!(read_item("44_story_foo").is_some());
    assert!(read_item("44").is_some());
}

#[test]
fn migrate_story_ids_to_numeric_noop_when_crdt_not_initialised() {
    // Must not panic when called before init.
    migrate_story_ids_to_numeric();
}

#[test]
fn migrate_story_ids_to_numeric_preserves_stage_and_name() {
    init_for_test();

    write_item(
        "45_bug_crash",
        "2_current",
        Some("Crash Bug"),
        Some("coder-1"),
        None,
        None,
        None,
        None,
        None,
        None,
    );

    migrate_story_ids_to_numeric();

    let item = read_item("45").expect("item must be accessible by numeric ID");
    assert_eq!(item.stage, "2_current");
    assert_eq!(item.name.as_deref(), Some("Crash Bug"));
    assert_eq!(item.agent.as_deref(), Some("coder-1"));
}

#[test]
fn migrate_names_from_slugs_fills_empty_names() {
    init_for_test();

    // Write an item without a name.
    write_item(
        "42_story_my_feature",
        "1_backlog",
        None,
        None,
        None,
        None,
        None,
        None,
        None,
        None,
    );

    // Before migration the name should be empty.
    let before = read_item("42_story_my_feature").unwrap();
    assert!(
        before.name.as_deref().unwrap_or("").is_empty(),
        "name should be empty before migration"
    );

    migrate_names_from_slugs();

    // After migration the name should be derived from the slug.
    let after = read_item("42_story_my_feature").unwrap();
    assert_eq!(
        after.name.as_deref(),
        Some("My feature"),
        "name should be derived from slug after migration"
    );
}

#[test]
fn migrate_names_from_slugs_leaves_existing_names_unchanged() {
    init_for_test();

    write_item(
        "43_story_named_item",
        "1_backlog",
        Some("Already Named"),
        None,
        None,
        None,
        None,
        None,
        None,
        None,
    );

    migrate_names_from_slugs();

    let after = read_item("43_story_named_item").unwrap();
    assert_eq!(
        after.name.as_deref(),
        Some("Already Named"),
        "pre-existing name must not be overwritten"
    );
}

#[test]
fn migrate_names_from_slugs_noop_when_crdt_not_initialised() {
    // Should not panic when called before init.
    // In practice get_crdt() returns None in a fresh thread.
    // We call it here just to confirm no panic.
    migrate_names_from_slugs();
}

// ── set_depends_on regression tests ──────────────────────────────────────

#[test]
fn set_depends_on_round_trip_and_clear() {
    use super::super::read::{check_unmet_deps_crdt, read_item};
    init_for_test();

    write_item(
        "872_test_target",
        "1_backlog",
        Some("Target"),
        None,
        None,
        None,
        None,
        None,
        None,
        None,
    );

    // Set depends_on to [837] and verify CRDT register holds the list.
    let ok = set_depends_on("872_test_target", &[837]);
    assert!(ok, "set_depends_on should return true for known item");
    let view = read_item("872_test_target").unwrap();
    assert_eq!(
        view.depends_on,
        Some(vec![837]),
        "CRDT register should hold [837]"
    );

    // Clear by passing an empty slice.
    let ok = set_depends_on("872_test_target", &[]);
    assert!(ok, "set_depends_on([]) should return true");
    let view = read_item("872_test_target").unwrap();
    assert_eq!(
        view.depends_on, None,
        "clearing should leave register unset"
    );

    // Auto-assigner sees no unmet dependency after clearing.
    let unmet = check_unmet_deps_crdt("872_test_target");
    assert!(
        unmet.is_empty(),
        "after clearing deps, auto-assigner should see no unmet dependencies"
    );
}

#[test]
fn set_depends_on_returns_false_for_unknown_story() {
    init_for_test();
    let ok = set_depends_on("nonexistent_story_872", &[1, 2, 3]);
    assert!(
        !ok,
        "set_depends_on should return false for unknown story_id"
    );
}

// ── set_mergemaster_attempted regression tests ───────────────────────────

#[test]
fn set_mergemaster_attempted_true_then_false_flips_register() {
    init_for_test();

    write_item(
        "873_story_mergemaster_flip",
        "4_merge",
        None,
        None,
        None,
        None,
        None,
        None,
        None,
        None,
    );

    // Set true — register must read back as true.
    let ok = set_mergemaster_attempted("873_story_mergemaster_flip", true);
    assert!(
        ok,
        "set_mergemaster_attempted should return true for known item"
    );
    let view = read_item("873_story_mergemaster_flip").unwrap();
    assert_eq!(
        view.mergemaster_attempted,
        Some(true),
        "CRDT register should hold true after setting true"
    );

    // Set false — register must flip back to false (not unset).
    let ok = set_mergemaster_attempted("873_story_mergemaster_flip", false);
    assert!(
        ok,
        "set_mergemaster_attempted(false) should return true for known item"
    );
    let view = read_item("873_story_mergemaster_flip").unwrap();
    assert_eq!(
        view.mergemaster_attempted,
        Some(false),
        "CRDT register should hold false after explicit clear"
    );
}

#[test]
fn set_mergemaster_attempted_returns_false_for_unknown_story() {
    init_for_test();
    let ok = set_mergemaster_attempted("nonexistent_story_mm", true);
    assert!(
        !ok,
        "set_mergemaster_attempted should return false for unknown story_id"
    );
}

// ── set_agent tests ──────────────────────────────────────────────────────

#[test]
fn set_agent_some_writes_name() {
    init_for_test();

    write_item(
        "871_story_set_agent_write",
        "2_current",
        Some("Set Agent Write"),
        None,
        None,
        None,
        None,
        None,
        None,
        None,
    );

    let found = set_agent("871_story_set_agent_write", Some("coder-1"));
    assert!(found, "set_agent should return true for an existing item");

    let item = read_item("871_story_set_agent_write").expect("item must exist");
    assert_eq!(
        item.agent.as_deref(),
        Some("coder-1"),
        "agent should be written to CRDT register"
    );
}

#[test]
fn set_agent_none_clears_register() {
    init_for_test();

    write_item(
        "871_story_set_agent_clear",
        "2_current",
        Some("Set Agent Clear"),
        Some("coder-2"),
        None,
        None,
        None,
        None,
        None,
        None,
    );

    // Confirm agent is set.
    let before = read_item("871_story_set_agent_clear").expect("item must exist");
    assert_eq!(before.agent.as_deref(), Some("coder-2"));

    // Clear it.
    let found = set_agent("871_story_set_agent_clear", None);
    assert!(found, "set_agent should return true for an existing item");

    let after = read_item("871_story_set_agent_clear").expect("item must exist");
    assert!(
        after.agent.as_deref().unwrap_or("").is_empty(),
        "agent should be cleared (empty string) after set_agent(None)"
    );
}

#[test]
fn set_agent_returns_false_for_unknown_story() {
    init_for_test();

    let found = set_agent("999_story_nonexistent", Some("coder-1"));
    assert!(
        !found,
        "set_agent should return false when story is not in the CRDT"
    );
}

// ── set_qa_mode regression tests ─────────────────────────────────────────

#[test]
fn set_qa_mode_round_trip_server_then_human() {
    use crate::io::story_metadata::QaMode;
    init_for_test();

    write_item(
        "869_story_qa_roundtrip",
        "1_backlog",
        None,
        None,
        None,
        None,
        None,
        None,
        None,
        None,
    );

    // Set qa=server via typed path and assert CRDT register reflects it.
    let ok = set_qa_mode("869_story_qa_roundtrip", Some(QaMode::Server));
    assert!(ok, "set_qa_mode should return true for known item");
    let view = read_item("869_story_qa_roundtrip").unwrap();
    assert_eq!(
        view.qa_mode.as_deref(),
        Some("server"),
        "CRDT register should hold \"server\""
    );

    // Set qa=human via typed path and assert CRDT register is updated.
    let ok = set_qa_mode("869_story_qa_roundtrip", Some(QaMode::Human));
    assert!(ok, "set_qa_mode should return true for known item");
    let view = read_item("869_story_qa_roundtrip").unwrap();
    assert_eq!(
        view.qa_mode.as_deref(),
        Some("human"),
        "CRDT register should hold \"human\""
    );

    // Clear via None — register goes back to unset.
    let ok = set_qa_mode("869_story_qa_roundtrip", None);
    assert!(ok, "set_qa_mode(None) should return true");
    let view = read_item("869_story_qa_roundtrip").unwrap();
    assert_eq!(
        view.qa_mode, None,
        "clearing qa_mode should leave register unset"
    );
}

#[test]
fn set_qa_mode_returns_false_for_unknown_story() {
    init_for_test();
    use crate::io::story_metadata::QaMode;
    let ok = set_qa_mode("nonexistent_story_qa", Some(QaMode::Server));
    assert!(!ok, "set_qa_mode should return false for unknown story_id");
}

// ── set_retry_count / bump_retry_count tests ─────────────────────────────

#[test]
fn bump_retry_count_increments_by_one() {
    init_for_test();
    write_item(
        "9001_story_bump_test",
        "2_current",
        None,
        None,
        None,
        None,
        None,
        None,
        None,
        None,
    );

    let v1 = bump_retry_count("9001_story_bump_test");
    assert_eq!(v1, 1, "first bump should return 1");

    let v2 = bump_retry_count("9001_story_bump_test");
    assert_eq!(v2, 2, "second bump should return 2");

    let item = read_item("9001_story_bump_test").expect("item must exist");
    assert_eq!(
        item.retry_count,
        Some(2),
        "CRDT must reflect final bump value"
    );
}

#[test]
fn set_retry_count_resets_to_zero() {
    init_for_test();
    write_item(
        "9002_story_set_test",
        "2_current",
        None,
        None,
        Some(5),
        None,
        None,
        None,
        None,
        None,
    );

    set_retry_count("9002_story_set_test", 0);

    let item = read_item("9002_story_set_test").expect("item must exist");
    assert_eq!(
        item.retry_count,
        Some(0),
        "set_retry_count(0) must reset to 0"
    );
}

#[test]
fn bump_returns_zero_for_missing_item() {
    init_for_test();
    let result = bump_retry_count("nonexistent_story");
    assert_eq!(result, 0, "bump on missing item should return 0 (no-op)");
}

#[tokio::test]
async fn bug_511_rowid_replay_preserves_field_update_after_list_insert() {
    let tmp = tempfile::tempdir().unwrap();
    let db_path = tmp.path().join("bug511.db");

    let options = SqliteConnectOptions::new()
        .filename(&db_path)
        .create_if_missing(true);
    let pool = SqlitePool::connect_with(options).await.unwrap();
    sqlx::migrate!("./migrations").run(&pool).await.unwrap();

    let kp = make_keypair();
    let mut crdt = BaseCrdt::<PipelineDoc>::new(&kp);

    // Insert 5 dummy items to advance items.our_seq to 5.
    for i in 0..5u32 {
        let sid = format!("{}_story_warmup", i);
        let item: JsonValue = json!({
            "story_id": sid,
            "stage": "1_backlog",
            "name": "",
            "agent": "",
            "retry_count": 0.0,
            "blocked": false,
            "depends_on": "",
        "claimed_by": "",
        "claimed_at": 0.0,
        })
        .into();
        let op = crdt.doc.items.insert(ROOT_ID, item).sign(&kp);
        crdt.apply(op.clone());
        // We don't persist these to the DB — they are pre-history.
    }

    // Now insert the real item. items.our_seq was 5, so this op gets seq=6.
    let target_item: JsonValue = json!({
        "story_id": "511_story_target",
        "stage": "1_backlog",
        "name": "Bug 511 target",
        "agent": "",
        "retry_count": 0.0,
        "blocked": false,
        "depends_on": "",
        "claimed_by": "",
        "claimed_at": 0.0,
    })
    .into();
    let insert_op = crdt.doc.items.insert(ROOT_ID, target_item).sign(&kp);
    crdt.apply(insert_op.clone());
    // insert_op.inner.seq == 6

    // Now update the stage. The stage LwwRegisterCrdt for this item starts
    // at our_seq=0, so this field op gets seq=1. Crucially: seq=1 < seq=6.
    let idx = rebuild_index(&crdt)["511_story_target"];
    let stage_op = crdt.doc.items[idx]
        .stage
        .set("2_current".to_string())
        .sign(&kp);
    crdt.apply(stage_op.clone());
    // stage_op.inner.seq == 1

    // Persist BOTH ops in causal order (insert first, update second).
    // This means insert_op gets rowid < stage_op rowid.
    let now = chrono::Utc::now().to_rfc3339();
    for op in [&insert_op, &stage_op] {
        let op_json = serde_json::to_string(op).unwrap();
        let op_id = hex::encode(&op.id());
        sqlx::query(
            "INSERT INTO crdt_ops (op_id, seq, op_json, created_at) VALUES (?1, ?2, ?3, ?4)",
        )
        .bind(&op_id)
        .bind(op.inner.seq as i64)
        .bind(&op_json)
        .bind(&now)
        .execute(&pool)
        .await
        .unwrap();
    }

    // Replay by rowid ASC (the fix). The insert must come before the field
    // update regardless of their field-level seq values.
    let rows: Vec<(String,)> = sqlx::query_as("SELECT op_json FROM crdt_ops ORDER BY rowid ASC")
        .fetch_all(&pool)
        .await
        .unwrap();

    let mut crdt2 = BaseCrdt::<PipelineDoc>::new(&kp);
    for (json_str,) in &rows {
        let op: SignedOp = serde_json::from_str(json_str).unwrap();
        crdt2.apply(op);
    }

    // The item must be in the CRDT and must reflect the stage update.
    let index2 = rebuild_index(&crdt2);
    assert!(
        index2.contains_key("511_story_target"),
        "item not found after rowid-order replay"
    );
    let idx2 = index2["511_story_target"];
    let view = extract_item_view(&crdt2.doc.items[idx2]).unwrap();
    assert_eq!(
        view.stage, "2_current",
        "stage field update lost during replay (bug 511 regression)"
    );

    // Confirm the bug is reproducible by replaying seq ASC instead.
    // With seq ASC the stage_op (seq=1) arrives before insert_op (seq=6),
    // fails ErrPathMismatch, and the item ends up at "1_backlog".
    let rows_wrong_order: Vec<(String,)> =
        sqlx::query_as("SELECT op_json FROM crdt_ops ORDER BY seq ASC")
            .fetch_all(&pool)
            .await
            .unwrap();

    let mut crdt3 = BaseCrdt::<PipelineDoc>::new(&kp);
    for (json_str,) in &rows_wrong_order {
        let op: SignedOp = serde_json::from_str(json_str).unwrap();
        crdt3.apply(op);
    }

    let index3 = rebuild_index(&crdt3);
    // With seq ASC replay, the item is created (insert_op eventually runs)
    // but the stage update is lost (it ran before the item existed).
    if let Some(idx3) = index3.get("511_story_target") {
        let view3 = extract_item_view(&crdt3.doc.items[*idx3]).unwrap();
        // The bug: stage is still "1_backlog" because the update was dropped.
        assert_eq!(
            view3.stage, "1_backlog",
            "expected seq-ASC replay to exhibit the bug (update lost)"
        );
    }
}

// ── Story 889 regression tests ───────────────────────────────────────────────

/// Regression for story 889: a tombstoned story must not be resurrected by
/// concurrent write_item calls racing the delete.  Spawns a tokio task that
/// hammers write_item every 10ms, tombstones the item mid-race, then verifies
/// the projection stays empty for ~500ms and remains empty after the writer
/// stops.
///
/// The tokio current_thread runtime keeps all tasks on the same OS thread, so
/// the thread-local test CRDT is visible to the spawned task.
#[tokio::test]
async fn tombstone_survives_concurrent_writes() {
    use std::sync::Arc;
    use std::sync::atomic::{AtomicBool, Ordering};

    use super::super::read::{evict_item, read_item};

    init_for_test();

    let story_id = "889_story_tombstone_concurrent";

    write_item(
        story_id,
        "2_current",
        Some("Tombstone Concurrent Test"),
        None,
        None,
        None,
        None,
        None,
        None,
        None,
    );
    assert!(
        read_item(story_id).is_some(),
        "item must exist before eviction"
    );

    let stop = Arc::new(AtomicBool::new(false));
    let stop_clone = stop.clone();

    let writer = tokio::task::spawn(async move {
        while !stop_clone.load(Ordering::Relaxed) {
            write_item(
                story_id,
                "2_current",
                Some("Tombstone Concurrent Test"),
                None,
                None,
                None,
                None,
                None,
                None,
                None,
            );
            tokio::time::sleep(tokio::time::Duration::from_millis(10)).await;
        }
    });

    tokio::time::sleep(tokio::time::Duration::from_millis(30)).await;

    evict_item(story_id).expect("evict_item must succeed");

    let deadline = tokio::time::Instant::now() + tokio::time::Duration::from_millis(500);
    while tokio::time::Instant::now() < deadline {
        assert!(
            read_item(story_id).is_none(),
            "tombstoned story must not reappear while concurrent writes are in flight"
        );
        tokio::time::sleep(tokio::time::Duration::from_millis(10)).await;
    }

    stop.store(true, Ordering::Relaxed);
    writer.await.unwrap();

    assert!(
        read_item(story_id).is_none(),
        "tombstoned story must stay gone after concurrent writer stops"
    );
}