//! The migrations are the contract texts byte for byte (`0001_init.sql` = `server-v1.sql`, SPEC §14.1;
//! `0002_categories_v2.sql` = `contracts/schema/migrations/0002_categories_v2.sql`, §14.1.1), connections carry the
//! §8.9 pragmas, a fresh database holds the fourteen defaults of AC-7.2, and a v1 database in use upgrades to schema
//! 2 without losing or changing a row.

use std::path::PathBuf;

use axum::http::{Method, StatusCode};
use kvitt_server::db;
use sqlx::{AssertSqlSafe, SqlitePool};

use crate::support::{ADMIN_ID, MEMBER_ID, TestApp, admin_token, authed};

fn manifest(path: &str) -> PathBuf {
    PathBuf::from(env!("CARGO_MANIFEST_DIR")).join(path)
}

/// The fourteen default categories of AC-7.2 and §14.1.1: id suffix, key, icon, colour, sort order, created_at and
/// the `server_version` on a fresh database (the ten v1 seeds 1 to 10, then migration 0002's rows 11 to 14).
const DEFAULTS: [(&str, &str, &str, &str, i64, &str, i64); 14] = [
    ("001", "groceries", "shopping_cart", "green", 10, V1_AT, 1),
    ("002", "restaurants", "restaurant", "orange", 20, V1_AT, 2),
    ("011", "housing", "key", "indigo", 25, V2_AT, 11),
    ("003", "home", "home", "brown", 30, V1_AT, 3),
    ("004", "utilities", "bolt", "yellow", 40, V1_AT, 4),
    ("012", "insurance", "shield", "slate", 45, V2_AT, 12),
    ("005", "transport", "directions_car", "blue", 50, V1_AT, 5),
    ("006", "travel", "flight", "teal", 60, V1_AT, 6),
    ("007", "entertainment", "movie", "purple", 70, V1_AT, 7),
    ("008", "health", "medical_services", "red", 80, V1_AT, 8),
    ("013", "children", "child_care", "lime", 85, V2_AT, 13),
    ("009", "shopping", "shopping_bag", "pink", 90, V1_AT, 9),
    ("014", "fees", "account_balance", "amber", 95, V2_AT, 14),
    ("00a", "other", "category", "grey", 100, V1_AT, 10),
];
const V1_AT: &str = "2026-10-17T00:00:00.000Z";
const V2_AT: &str = "2026-10-18T00:00:00.000Z";
const ID_PREFIX: &str = "01920000-0000-7000-8000-000000000";
const NEW_IDS: [&str; 4] = [
    "01920000-0000-7000-8000-000000000011",
    "01920000-0000-7000-8000-000000000012",
    "01920000-0000-7000-8000-000000000013",
    "01920000-0000-7000-8000-000000000014",
];

#[test]
fn migration_0001_is_byte_identical_to_contract_schema() {
    let migration = std::fs::read(manifest("migrations/0001_init.sql")).unwrap();
    let contract = std::fs::read(manifest("../../../contracts/schema/server-v1.sql")).unwrap();
    assert!(
        migration == contract,
        "migrations/0001_init.sql differs from contracts/schema/server-v1.sql"
    );
}

#[test]
fn migration_0002_is_byte_identical_to_contract_migration() {
    let migration = std::fs::read(manifest("migrations/0002_categories_v2.sql")).unwrap();
    let contract = std::fs::read(manifest(
        "../../../contracts/schema/migrations/0002_categories_v2.sql",
    ))
    .unwrap();
    assert!(
        migration == contract,
        "migrations/0002_categories_v2.sql differs from contracts/schema/migrations/0002_categories_v2.sql"
    );
}

#[test]
fn the_embedded_migrator_holds_exactly_those_migrations() {
    let v1 = std::fs::read_to_string(manifest("../../../contracts/schema/server-v1.sql")).unwrap();
    let v2 = std::fs::read_to_string(manifest(
        "../../../contracts/schema/migrations/0002_categories_v2.sql",
    ))
    .unwrap();
    let migrations: Vec<_> = db::MIGRATOR.iter().collect();
    assert_eq!(migrations.len(), 2);
    assert_eq!(migrations[0].version, 1);
    assert_eq!(migrations[0].sql.as_ref(), v1.as_str());
    assert_eq!(migrations[1].version, 2);
    assert_eq!(migrations[1].sql.as_ref(), v2.as_str());
    // sqlx wraps each migration in one transaction unless it opts out (SPEC §14.1.1 relies on it).
    assert!(migrations.iter().all(|m| !m.no_tx));
    assert_eq!(db::SCHEMA_VERSION, 2);
}

/// Every row of `table` in a stable order, each rendered with SQLite's `quote()` per column (type-exact).
async fn dump(pool: &SqlitePool, table: &str, filter: &str) -> Vec<String> {
    let columns: Vec<String> =
        sqlx::query_scalar("SELECT name FROM pragma_table_info(?) ORDER BY cid")
            .bind(table)
            .fetch_all(pool)
            .await
            .unwrap();
    assert!(!columns.is_empty(), "{table} has no columns");
    let row = columns
        .iter()
        .map(|c| format!("quote({c})"))
        .collect::<Vec<_>>()
        .join(" || '|' || ");
    let order = columns.join(", ");
    sqlx::query_scalar(AssertSqlSafe(format!(
        "SELECT {row} FROM {table} {filter} ORDER BY {order}"
    )))
    .fetch_all(pool)
    .await
    .unwrap()
}

async fn user_tables(pool: &SqlitePool) -> Vec<String> {
    sqlx::query_scalar(
        "SELECT name FROM sqlite_master WHERE type = 'table' AND name NOT LIKE 'sqlite_%' \
         AND name <> '_sqlx_migrations' ORDER BY name",
    )
    .fetch_all(pool)
    .await
    .unwrap()
}

async fn scalar_i64(pool: &SqlitePool, sql: &'static str) -> i64 {
    sqlx::query_scalar(sql).fetch_one(pool).await.unwrap()
}

async fn foreign_key_violations(pool: &SqlitePool) -> usize {
    sqlx::query("PRAGMA foreign_key_check")
        .fetch_all(pool)
        .await
        .unwrap()
        .len()
}

type CategoryRow = (
    String,
    Option<String>,
    Option<String>,
    String,
    String,
    i64,
    String,
    String,
    Option<String>,
    Option<String>,
    i64,
);

async fn categories(pool: &SqlitePool, filter: &str) -> Vec<CategoryRow> {
    sqlx::query_as(AssertSqlSafe(format!(
        "SELECT id, default_key, name, icon, color, sort_order, created_at, updated_at, archived_at, deleted_at, \
         server_version FROM categories {filter} ORDER BY sort_order, id"
    )))
    .fetch_all(pool)
    .await
    .unwrap()
}

#[tokio::test]
async fn a_fresh_database_holds_exactly_the_fourteen_defaults() {
    let app = TestApp::empty().await;
    let pool = &app.state.db;
    let rows = categories(pool, "").await;
    let expected: Vec<CategoryRow> = DEFAULTS
        .iter()
        .map(|&(suffix, key, icon, color, sort, at, version)| {
            (
                format!("{ID_PREFIX}{suffix}"),
                Some(key.to_owned()),
                None,
                icon.to_owned(),
                color.to_owned(),
                sort,
                at.to_owned(),
                at.to_owned(),
                None,
                None,
                version,
            )
        })
        .collect();
    assert_eq!(rows, expected);
    assert_eq!(
        scalar_i64(pool, "SELECT value FROM sync_sequence WHERE id = 1").await,
        14
    );
    assert_eq!(foreign_key_violations(pool).await, 0);
    // The rebuilt table keeps the v1 constraints and accepts exactly the fourteen keys.
    let insert = |key: &'static str, version: i64| {
        sqlx::query(
            "INSERT INTO categories (id, default_key, name, icon, color, sort_order, created_at, updated_at, \
             server_version) VALUES (?, ?, NULL, 'home', 'grey', 1, ?, ?, ?)",
        )
        .bind(format!("0192f000-0000-7000-8000-{version:012}"))
        .bind(key)
        .bind(V2_AT)
        .bind(V2_AT)
        .bind(version)
        .execute(pool)
    };
    assert!(insert("pets", 100).await.is_err(), "unknown key rejected");
    assert!(
        insert("fees", 101).await.is_err(),
        "default_key stays unique"
    );
    let nameless_custom = sqlx::query(
        "INSERT INTO categories (id, default_key, name, icon, color, sort_order, created_at, updated_at, \
         server_version) VALUES ('0192f000-0000-7000-8000-000000000102', NULL, NULL, 'home', 'grey', 1, ?, ?, 102)",
    )
    .bind(V2_AT)
    .bind(V2_AT)
    .execute(pool)
    .await;
    assert!(nameless_custom.is_err(), "a custom category needs a name");
}

/// A v1 database in use: the household, a custom category, a renamed and an archived default, an account, a
/// recurring template and expenses referencing default and custom categories. Rows take versions 15 to 23 and the
/// sequence ends at 23.
async fn fill_v1(app: &TestApp) {
    let pool = &app.state.db;
    app.seed_household().await;
    let statements = [
        "INSERT INTO categories (id, default_key, name, icon, color, sort_order, created_at, updated_at, \
         archived_at, deleted_at, server_version) VALUES ('0192c000-0000-7000-8000-000000000001', NULL, 'Hemförsäkring', \
         'pets', 'lime', 110, '2026-10-17T09:00:00.000Z', '2026-10-17T09:00:00.000Z', NULL, NULL, 17)",
        "UPDATE categories SET name = 'Mat', updated_at = '2026-10-17T09:01:00.000Z', server_version = 18 \
         WHERE default_key = 'groceries'",
        "UPDATE categories SET archived_at = '2026-10-17T09:02:00.000Z', updated_at = '2026-10-17T09:02:00.000Z', \
         server_version = 19 WHERE default_key = 'other'",
        "INSERT INTO accounts (id, name, name_key, created_by_user_id, created_at, updated_at, server_version) \
         VALUES ('0192b000-0000-7000-8000-000000000001', 'Vardag', 'vardag', '0192a000-0000-7000-8000-000000000001', \
         '2026-10-17T09:03:00.000Z', '2026-10-17T09:03:00.000Z', 20)",
        "INSERT INTO account_default_shares (account_id, user_id, share_bp) VALUES \
         ('0192b000-0000-7000-8000-000000000001', '0192a000-0000-7000-8000-000000000001', 5000), \
         ('0192b000-0000-7000-8000-000000000001', '0192a000-0000-7000-8000-000000000002', 5000)",
        "INSERT INTO recurring_templates (id, account_id, category_id, amount_ore, description, notes, payer_user_id, \
         split_mode, day_of_month, start_period, end_period, paused, last_generated_period, created_by_user_id, \
         updated_by_user_id, created_at, updated_at, deleted_at, server_version) VALUES \
         ('0192d000-0000-7000-8000-000000000001', '0192b000-0000-7000-8000-000000000001', \
         '01920000-0000-7000-8000-000000000003', 1250000, 'Hyra', '', '0192a000-0000-7000-8000-000000000001', \
         'default', 25, '2026-10', NULL, 0, '2026-10', '0192a000-0000-7000-8000-000000000001', \
         '0192a000-0000-7000-8000-000000000001', '2026-10-17T09:04:00.000Z', '2026-10-17T09:04:00.000Z', NULL, 21)",
        "INSERT INTO expenses (id, account_id, category_id, amount_ore, description, notes, expense_date, \
         payer_user_id, split_mode, recurring_template_id, recurring_period, import_key, created_by_user_id, \
         updated_by_user_id, updated_by_device_id, created_at, updated_at, deleted_at, server_received_at, \
         server_version) VALUES ('0192e000-0000-7000-8000-000000000001', '0192b000-0000-7000-8000-000000000001', \
         '01920000-0000-7000-8000-000000000003', 1250000, 'Hyra', '', '2026-10-25', \
         '0192a000-0000-7000-8000-000000000001', 'default', '0192d000-0000-7000-8000-000000000001', '2026-10', NULL, \
         '0192a000-0000-7000-8000-000000000001', '0192a000-0000-7000-8000-000000000001', NULL, \
         '2026-10-17T09:05:00.000Z', '2026-10-17T09:05:00.000Z', NULL, '2026-10-17T09:05:00.000Z', 22)",
        "INSERT INTO expenses (id, account_id, category_id, amount_ore, description, notes, expense_date, \
         payer_user_id, split_mode, recurring_template_id, recurring_period, import_key, created_by_user_id, \
         updated_by_user_id, updated_by_device_id, created_at, updated_at, deleted_at, server_received_at, \
         server_version) VALUES ('0192e000-0000-7000-8000-000000000002', '0192b000-0000-7000-8000-000000000001', \
         '0192c000-0000-7000-8000-000000000001', 34900, 'Försäkring', 'Kvartal', '2026-10-16', \
         '0192a000-0000-7000-8000-000000000002', 'full', NULL, NULL, NULL, \
         '0192a000-0000-7000-8000-000000000002', '0192a000-0000-7000-8000-000000000002', NULL, \
         '2026-10-17T09:06:00.000Z', '2026-10-17T09:06:00.000Z', NULL, '2026-10-17T09:06:00.000Z', 23)",
        "INSERT INTO expense_splits (expense_id, user_id, share_ore, share_bp) VALUES \
         ('0192e000-0000-7000-8000-000000000001', '0192a000-0000-7000-8000-000000000001', 625000, 5000), \
         ('0192e000-0000-7000-8000-000000000001', '0192a000-0000-7000-8000-000000000002', 625000, 5000), \
         ('0192e000-0000-7000-8000-000000000002', '0192a000-0000-7000-8000-000000000001', 0, NULL), \
         ('0192e000-0000-7000-8000-000000000002', '0192a000-0000-7000-8000-000000000002', 34900, NULL)",
        "UPDATE sync_sequence SET value = 23 WHERE id = 1",
    ];
    for sql in statements {
        sqlx::query(sql)
            .execute(pool)
            .await
            .unwrap_or_else(|e| panic!("{e}: {sql}"));
    }
}

#[tokio::test]
async fn a_v1_database_in_use_upgrades_to_schema_2_keeping_every_row() {
    let app = TestApp::at_v1().await;
    let pool = &app.state.db;
    assert_eq!(
        sqlx::query_scalar::<_, String>("SELECT value FROM meta WHERE key = 'schema_version'")
            .fetch_one(pool)
            .await
            .unwrap(),
        "1"
    );
    assert_eq!(
        scalar_i64(pool, "SELECT COUNT(*) FROM categories").await,
        10
    );
    fill_v1(&app).await;
    let old_sequence = scalar_i64(pool, "SELECT value FROM sync_sequence WHERE id = 1").await;
    assert_eq!(old_sequence, 23);
    let epoch: String = sqlx::query_scalar("SELECT value FROM meta WHERE key = 'sync_epoch'")
        .fetch_one(pool)
        .await
        .unwrap();

    let tables = user_tables(pool).await;
    let mut before = Vec::new();
    for table in &tables {
        if table != "meta" && table != "sync_sequence" {
            before.push((table.clone(), dump(pool, table, "").await));
        }
    }

    db::migrate(pool).await.unwrap();

    // The connection that ran the migration had foreign keys on (SPEC §8.9), and nothing dangles afterwards.
    let mut conn = pool.acquire().await.unwrap();
    let fk: i64 = sqlx::query_scalar("PRAGMA foreign_keys")
        .fetch_one(&mut *conn)
        .await
        .unwrap();
    assert_eq!(fk, 1);
    drop(conn);
    assert_eq!(foreign_key_violations(pool).await, 0);
    assert_eq!(
        user_tables(pool).await,
        tables,
        "no table added or left behind"
    );
    assert_eq!(
        sqlx::query_scalar::<_, String>("SELECT value FROM meta WHERE key = 'schema_version'")
            .fetch_one(pool)
            .await
            .unwrap(),
        "2"
    );
    assert_eq!(
        sqlx::query_scalar::<_, String>("SELECT value FROM meta WHERE key = 'sync_epoch'")
            .fetch_one(pool)
            .await
            .unwrap(),
        epoch
    );
    assert_eq!(
        scalar_i64(pool, "SELECT value FROM sync_sequence WHERE id = 1").await,
        old_sequence + 4
    );

    // Every earlier row, categories included, is unchanged.
    let old_only = format!("WHERE id NOT IN ('{}')", NEW_IDS.join("', '"));
    for (table, rows) in &before {
        let filter = if table == "categories" {
            old_only.as_str()
        } else {
            ""
        };
        assert_eq!(&dump(pool, table, filter).await, rows, "{table} changed");
    }

    // The four new rows, versions after the old sequence value.
    let new_rows = categories(pool, &format!("WHERE id IN ('{}')", NEW_IDS.join("', '"))).await;
    let expected: Vec<CategoryRow> = DEFAULTS
        .iter()
        .filter(|d| d.5 == V2_AT)
        .zip(1..)
        .map(|(&(suffix, key, icon, color, sort, at, _), n)| {
            (
                format!("{ID_PREFIX}{suffix}"),
                Some(key.to_owned()),
                None,
                icon.to_owned(),
                color.to_owned(),
                sort,
                at.to_owned(),
                at.to_owned(),
                None,
                None,
                old_sequence + n,
            )
        })
        .collect();
    assert_eq!(new_rows, expected);
    assert_eq!(
        scalar_i64(pool, "SELECT COUNT(*) FROM categories").await,
        15
    );

    // A phone at the old cursor pulls exactly the four new categories.
    let reply = app
        .send(authed(
            Method::GET,
            &format!("/sync?since={old_sequence}"),
            &admin_token(),
        ))
        .await;
    assert_eq!(reply.status, StatusCode::OK);
    let page = &reply.json;
    assert_eq!(page["since"], old_sequence);
    assert_eq!(page["next_since"], old_sequence + 4);
    assert_eq!(page["has_more"], false);
    let ids: Vec<&str> = page["categories"]
        .as_array()
        .unwrap()
        .iter()
        .map(|c| c["id"].as_str().unwrap())
        .collect();
    assert_eq!(ids, NEW_IDS);
    for array in [
        "users",
        "accounts",
        "recurring_templates",
        "expenses",
        "settlements",
        "audit_entries",
    ] {
        assert_eq!(page[array], serde_json::json!([]), "{array}");
    }
    assert_eq!(page["categories"][1]["default_key"], "insurance");
    assert_eq!(page["categories"][1]["color"], "slate");
    // The users the seeding referenced are still the household.
    let users: Vec<String> = sqlx::query_scalar("SELECT id FROM users ORDER BY id")
        .fetch_all(pool)
        .await
        .unwrap();
    assert_eq!(users, [ADMIN_ID, MEMBER_ID]);

    // A second run is a no-op.
    db::migrate(pool).await.unwrap();
    assert_eq!(
        scalar_i64(pool, "SELECT COUNT(*) FROM categories").await,
        15
    );
}

#[tokio::test]
async fn migrated_database_has_schema_version_seed_rows_and_pragmas() {
    let app = TestApp::empty().await;
    let pool = &app.state.db;
    let version: String = sqlx::query_scalar("SELECT value FROM meta WHERE key = 'schema_version'")
        .fetch_one(pool)
        .await
        .unwrap();
    assert_eq!(version, db::SCHEMA_VERSION.to_string());
    let epoch: String = sqlx::query_scalar("SELECT value FROM meta WHERE key = 'sync_epoch'")
        .fetch_one(pool)
        .await
        .unwrap();
    assert_eq!(epoch.len(), 32);
    let categories: i64 = sqlx::query_scalar("SELECT COUNT(*) FROM categories")
        .fetch_one(pool)
        .await
        .unwrap();
    assert_eq!(categories, 14);

    let mut conn = pool.acquire().await.unwrap();
    let journal: String = sqlx::query_scalar("PRAGMA journal_mode")
        .fetch_one(&mut *conn)
        .await
        .unwrap();
    assert_eq!(journal, "wal");
    let fk: i64 = sqlx::query_scalar("PRAGMA foreign_keys")
        .fetch_one(&mut *conn)
        .await
        .unwrap();
    assert_eq!(fk, 1);
    let sync: i64 = sqlx::query_scalar("PRAGMA synchronous")
        .fetch_one(&mut *conn)
        .await
        .unwrap();
    assert_eq!(sync, 1, "synchronous = NORMAL");
    let busy: i64 = sqlx::query_scalar("PRAGMA busy_timeout")
        .fetch_one(&mut *conn)
        .await
        .unwrap();
    assert_eq!(busy, 5000);
}

#[tokio::test]
async fn migrating_twice_is_a_no_op() {
    let app = TestApp::empty().await;
    db::migrate(&app.state.db).await.unwrap();
}

#[tokio::test]
async fn server_version_sequence_starts_after_the_seed_and_increments() {
    let app = TestApp::empty().await;
    let mut tx = db::begin_immediate(&app.state.db).await.unwrap();
    assert_eq!(db::next_server_version(&mut tx).await.unwrap(), 15);
    assert_eq!(db::next_server_version(&mut tx).await.unwrap(), 16);
    tx.commit().await.unwrap();
    let mut conn = app.state.db.acquire().await.unwrap();
    assert_eq!(
        db::sequence::current_server_version(&mut conn)
            .await
            .unwrap(),
        16
    );
}