// Oak Video Editor - Non-Linear Video Editor
// Copyright (C) 2026 Oak Team
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

//! PostgreSQL variants of the database-backend integration tests (plan
//! M13 D3): the same behaviors `database_test.rs` runs against SQLite,
//! driven by the shared fixtures in `tests/common/mod.rs`, against a
//! real PostgreSQL server.
//!
//! Gating: when `OAK_TEST_PG_URL` (a libpq URL such as
//! `postgres://user:pass@host:5432/db`) is set, every test connects to
//! that server and runs for real; when it is absent the tests skip with
//! a note on stderr, so `cargo test -p oakstorage` is green without a
//! PostgreSQL server (CI included). The URL should point at a dedicated
//! test database: each test resets the four schema tables (DROP + the
//! migration recreates them on connect), and the tests run serialized
//! against the shared database.

mod common;

use std::sync::Mutex;

use sea_orm::entity::prelude::*;
use sea_orm::{ConnectionTrait, QueryOrder};
use oaknode::id::NodeId;
use oaknode::value::NodeValue;
use oakstorage::backend::StorageBackend;
use oakstorage::backends::database::entities::{journal, project, snapshot};
use oakstorage::backends::database::{
	derive_stats, DatabaseBackend, KIND_IMPORT, KIND_REDO, ProjectStats, SNAPSHOT_KEEP,
};
use oakstorage::error::{
	OAKSTORAGE_E_FORMAT, OAKSTORAGE_E_INVALID, OAKSTORAGE_E_NOT_FOUND, OAKSTORAGE_OK,
};
use oakstorage::nodeutil::project_arc;
use oakstorage::registry::Registry;
use oakstorage::uri::StorageUri;

use common::*;

// ---------------------------------------------------------------------------
// Gating and isolation
// ---------------------------------------------------------------------------

/// The `OAK_TEST_PG_URL` connection string (None when not configured).
fn pg_url() -> Option<String> {
	std::env::var("OAK_TEST_PG_URL")
		.ok()
		.filter(|s| !s.trim().is_empty())
}

/// Strip the `postgres://` / `postgresql://` scheme from a connection
/// URL to get the `oakdb+pg://` uri body.
fn pg_body(url: &str) -> &str {
	url.strip_prefix("postgres://")
		.or_else(|| url.strip_prefix("postgresql://"))
		.unwrap_or(url)
}

/// Reset the four schema tables (the migration recreates them on the
/// next connection). Serialized with the other PG tests.
fn reset_tables(url: &str) {
	inspect_pg(url, |conn| async move {
		for table in ["journal", "snapshots", "settings", "projects"] {
			conn.execute_raw(sea_orm::Statement::from_string(
				sea_orm::DatabaseBackend::Postgres,
				format!("DROP TABLE IF EXISTS {table} CASCADE"),
			))
			.await
			.unwrap();
		}
	});
}

/// Run `f` with `(pg_url, oakdb+pg uri)` for an isolated test session.
/// Skips (with a note) when `OAK_TEST_PG_URL` is absent; otherwise the
/// tables are reset and the test runs against the shared database (the
/// tests share one server and one schema, so they run one at a time).
fn with_pg_uri(tag: &str, f: impl FnOnce(&str, &str)) {
	let Some(url) = pg_url() else {
		eprintln!("OAK_TEST_PG_URL is not set — skipping the PostgreSQL variant of '{tag}'");
		return;
	};
	static PG_LOCK: Mutex<()> = Mutex::new(());
	let _g = PG_LOCK.lock().unwrap_or_else(|e| e.into_inner());
	reset_tables(&url);
	let uri = format!("oakdb+pg://{}", pg_body(&url));
	f(&url, &uri);
}

// ---------------------------------------------------------------------------
// Round-trip through a fresh session
// ---------------------------------------------------------------------------

#[test]
fn pg_roundtrip_field_by_field() {
	with_pg_uri("roundtrip_field_by_field", |url, uri| {
		let backend = DatabaseBackend::new();

		let project = build_full_project();
		let uuid = uuid_of(&project);
		save_project(&backend, &project, uri).unwrap();

		// A new backend instance = a new session; the library row is
		// selected explicitly by uuid.
		let session = DatabaseBackend::new();
		let (loaded_uuid, loaded) = load_project(&session, &project_uri(uri, &uuid));
		assert_eq!(loaded_uuid, uuid);
		{
			let o = project.lock().unwrap();
			let l = loaded.lock().unwrap();
			assert_full_fields(&o, &l);
		}

		// The default (no ?project=) pick returns the same single row.
		let session = DatabaseBackend::new();
		let (loaded_uuid, _) = load_project(&session, uri);
		assert_eq!(loaded_uuid, uuid);

		// The settings mirror carries the current keys.
		let uuid_c = uuid.clone();
		let row = inspect_pg(url, move |conn| async move {
			project::Entity::find()
				.filter(project::Column::Uuid.eq(&uuid_c))
				.one(&conn)
				.await
				.unwrap()
				.unwrap()
				.id
		});
		let mirrored = settings_rows_pg(url, row);
		assert!(
			mirrored.contains(&("projectname".to_string(), "full-fixture".to_string())),
			"{mirrored:?}"
		);
	});
}

// ---------------------------------------------------------------------------
// Journal semantics: import, diff, no-op save
// ---------------------------------------------------------------------------

/// First save is one `kind='import'` command carrying every node plus
/// the settings pseudo-node (plan §2); the project row advances to seq 1.
#[test]
fn pg_first_save_is_an_import_command() {
	with_pg_uri("first_save_is_an_import_command", |url, uri| {
		let backend = DatabaseBackend::new();

		let project = build_full_project();
		let uuid = uuid_of(&project);
		let node_count = project.lock().unwrap().graph.node_count();
		save_project(&backend, &project, uri).unwrap();

		let uuid_c = uuid.clone();
		let rows = inspect_pg(url, move |conn| async move {
			let proj = project::Entity::find()
				.filter(project::Column::Uuid.eq(&uuid_c))
				.one(&conn)
				.await
				.unwrap()
				.unwrap();
			let rows = journal::Entity::find()
				.filter(journal::Column::ProjectId.eq(proj.id))
				.order_by_asc(journal::Column::Seq)
				.order_by_asc(journal::Column::NodeIdentity)
				.all(&conn)
				.await
				.unwrap();
			(proj.id, proj.command_seq, rows)
		});
		let (pid, command_seq, rows) = rows;
		assert_eq!(command_seq, 1);
		assert_eq!(
			rows.len(),
			node_count + 1,
			"every node + the settings pseudo-node"
		);
		assert!(rows.iter().all(|r| r.seq == 1 && r.kind == KIND_IMPORT), "one import command");
		assert!(rows.iter().all(|r| r.old_xml.is_none()), "import has no before images");
		assert!(rows.iter().all(|r| r.new_xml.is_some()), "import has after images");
		// The settings pseudo-node (identity 0) is present.
		assert!(rows.iter().any(|r| r.node_identity == 0), "settings row present");
		assert_eq!(
			rows.iter().filter(|r| r.node_identity == 0).count(),
			1,
			"exactly one settings row"
		);
		// The real-node rows use the +1 offset (settings 0 reserved).
		assert!(rows.iter().all(|r| r.node_identity >= 1 || r.node_identity == 0));
		// The node fragments round-trip: the settings row holds the settings
		// element.
		let settings_row = rows.iter().find(|r| r.node_identity == 0).unwrap();
		assert!(settings_row.new_xml.as_deref().unwrap().starts_with("<settings>"));
		let _ = pid;
	});
}

/// A later save is a diff: only the changed nodes land as `kind='redo'`
/// rows with both before and after images (plan §0).
#[test]
fn pg_later_saves_are_diffs() {
	with_pg_uri("later_saves_are_diffs", |url, uri| {
		let backend = DatabaseBackend::new();

		let project = build_full_project();
		let uuid = uuid_of(&project);
		save_project(&backend, &project, uri).unwrap();

		// Change one math node's value and one setting key.
		{
			let mut p = project.lock().unwrap();
			let math_ids: Vec<NodeId> = p
				.graph
				.node_ids()
				.into_iter()
				.filter(|id| p.graph.get(*id).unwrap().behavior.type_id() == MATH)
				.collect();
			let a = math_ids[0];
			p.graph
				.get_mut(a)
				.unwrap()
				.core
				.set_standard_value("param_a_in", -1, NodeValue::Float(9.5));
			p.settings.insert("projectname".to_string(), "diffed".to_string());
		}
		save_project(&backend, &project, uri).unwrap();

		let uuid_c = uuid.clone();
		let rows = inspect_pg(url, move |conn| async move {
			let proj = project::Entity::find()
				.filter(project::Column::Uuid.eq(&uuid_c))
				.one(&conn)
				.await
				.unwrap()
				.unwrap();
			let rows = journal::Entity::find()
				.filter(journal::Column::ProjectId.eq(proj.id))
				.all(&conn)
				.await
				.unwrap();
			(proj.id, proj.command_seq, rows)
		});
		let (pid, command_seq, rows) = rows;
		assert_eq!(command_seq, 2);
		let seq2: Vec<&journal::Model> = rows.iter().filter(|r| r.seq == 2).collect();
		assert_eq!(seq2.len(), 2, "one changed node + the settings row, nothing else");
		assert!(seq2.iter().all(|r| r.kind == KIND_REDO));
		assert!(
			seq2.iter().all(|r| r.old_xml.is_some() && r.new_xml.is_some()),
			"diff carries both images"
		);
		let settings_row = seq2.iter().find(|r| r.node_identity == 0).unwrap();
		assert!(settings_row.new_xml.as_deref().unwrap().contains(">diffed<"));
		let _ = pid;

		// Head state after the diff reflects both changes.
		let session = DatabaseBackend::new();
		let (_, loaded) = load_project(&session, &project_uri(uri, &uuid));
		{
			let l = loaded.lock().unwrap();
			let math_ids: Vec<NodeId> = l
				.graph
				.node_ids()
				.into_iter()
				.filter(|id| l.graph.get(*id).unwrap().behavior.type_id() == MATH)
				.collect();
			assert_eq!(
				l.graph.get(math_ids[0]).unwrap().core.standard_value("param_a_in", -1),
				NodeValue::Float(9.5)
			);
			assert_eq!(
				l.settings.get("projectname").cloned(),
				Some("diffed".to_string())
			);
		}
	});
}

/// A save that changes nothing bumps no command seq and writes no rows.
#[test]
fn pg_no_op_save_is_a_touch_only() {
	with_pg_uri("no_op_save_is_a_touch_only", |url, uri| {
		let backend = DatabaseBackend::new();

		let project = build_full_project();
		let uuid = uuid_of(&project);
		save_project(&backend, &project, uri).unwrap();
		save_project(&backend, &project, uri).unwrap();

		let uuid_c = uuid.clone();
		let (head, count) = inspect_pg(url, move |conn| async move {
			let proj = project::Entity::find()
				.filter(project::Column::Uuid.eq(&uuid_c))
				.one(&conn)
				.await
				.unwrap()
				.unwrap();
			let n = journal::Entity::find()
				.filter(journal::Column::ProjectId.eq(proj.id))
				.count(&conn)
				.await
				.unwrap();
			(proj.command_seq, n)
		});
		assert_eq!(head, 1, "no-op save keeps the head seq");
		// The import wrote 12 nodes + 1 settings row; the no-op added none.
		assert_eq!(count, 13, "only the import rows remain");
	});
}

// ---------------------------------------------------------------------------
// Snapshot + journal replay and undo to any point
// ---------------------------------------------------------------------------

/// With `Storage/SnapshotIntervalSec` ≤ 0 every dirty save writes a
/// snapshot; the newest snapshot is the replay base and the journal rows
/// after it are applied on top. Deleting every snapshot still recovers
/// the same state from an empty base plus the full journal (plan §0).
#[test]
fn pg_snapshot_and_journal_replay() {
	with_pg_uri("snapshot_and_journal_replay", |url, uri| {
		let backend = DatabaseBackend::new();

		with_config("Storage", "SnapshotIntervalSec", 0, || {
			let project = build_full_project();
			let uuid = uuid_of(&project);
			save_project(&backend, &project, uri).unwrap();
			// Second command: one value change.
			{
				let mut p = project.lock().unwrap();
				let math_ids: Vec<NodeId> = p
					.graph
					.node_ids()
					.into_iter()
					.filter(|id| p.graph.get(*id).unwrap().behavior.type_id() == MATH)
					.collect();
				p.graph
					.get_mut(math_ids[0])
					.unwrap()
					.core
					.set_standard_value("param_a_in", -1, NodeValue::Float(7.25));
			}
			save_project(&backend, &project, uri).unwrap();

			// Both saves produced snapshots (head seq 2).
			let uuid_c = uuid.clone();
			let snaps = inspect_pg(url, move |conn| async move {
				let proj = project::Entity::find()
					.filter(project::Column::Uuid.eq(&uuid_c))
					.one(&conn)
					.await
					.unwrap()
					.unwrap();
				snapshot::Entity::find()
					.filter(snapshot::Column::ProjectId.eq(proj.id))
					.all(&conn)
					.await
					.unwrap()
			});
			assert_eq!(snaps.len(), 2, "one snapshot per dirty save");

			// Load (head): snapshot seq 2 is the base, nothing after it.
			let session = DatabaseBackend::new();
			let (_, loaded) = load_project(&session, &project_uri(uri, &uuid));
			{
				let o = project.lock().unwrap();
				let l = loaded.lock().unwrap();
				assert_full_fields(&o, &l);
			}

			// Destroy the snapshots: replay degrades to empty base + full
			// journal and still reconstructs the head.
			let uuid_c = uuid.clone();
			inspect_pg(url, move |conn| async move {
				let proj = project::Entity::find()
					.filter(project::Column::Uuid.eq(&uuid_c))
					.one(&conn)
					.await
					.unwrap()
					.unwrap();
				snapshot::Entity::delete_many()
					.filter(snapshot::Column::ProjectId.eq(proj.id))
					.exec(&conn)
					.await
					.unwrap();
			});
			let session = DatabaseBackend::new();
			let (_, loaded) = load_project(&session, &project_uri(uri, &uuid));
			{
				let o = project.lock().unwrap();
				let l = loaded.lock().unwrap();
				assert_full_fields(&o, &l);
			}
		});
	});
}

/// The journal is the persistent undo history: `load_at(seq)` replays to
/// any point (plan §0 "撤销到任意点").
#[test]
fn pg_undo_to_any_point() {
	with_pg_uri("undo_to_any_point", |_url, uri| {
		let backend = DatabaseBackend::new();

		let project = build_full_project();
		let uuid = uuid_of(&project);
		let math_a = {
			let p = project.lock().unwrap();
			p.graph
				.node_ids()
				.into_iter()
				.find(|id| p.graph.get(*id).unwrap().behavior.type_id() == MATH)
				.unwrap()
		};
		// Command 1: value 2.5 (fixture default).
		save_project(&backend, &project, uri).unwrap();
		// Command 2: value 6.0.
		{
			let mut p = project.lock().unwrap();
			p.graph
				.get_mut(math_a)
				.unwrap()
				.core
				.set_standard_value("param_a_in", -1, NodeValue::Float(6.0));
		}
		save_project(&backend, &project, uri).unwrap();
		// Command 3: add a node.
		let (new_id, value) = {
			let mut p = project.lock().unwrap();
			let (core, behavior) = (oaknode::factory::Factory::global().find(MATH).unwrap().create)();
			let id = p.graph.add_node(core, behavior);
			p.graph
				.get_mut(id)
				.unwrap()
				.core
				.set_standard_value("param_a_in", -1, NodeValue::Float(11.0));
			let v = p
				.graph
				.get(id)
				.unwrap()
				.core
				.standard_value("param_a_in", -1);
			(id, v)
		};
		save_project(&backend, &project, uri).unwrap();

		// Head (seq 3): the extra node exists.
		let session = DatabaseBackend::new();
		let (_, head) = load_project(&session, &project_uri(uri, &uuid));
		{
			let h = head.lock().unwrap();
			assert!(h.graph.is_valid(new_id), "node added in command 3 is live");
			assert_eq!(
				h.graph.get(new_id).unwrap().core.standard_value("param_a_in", -1),
				value
			);
		}

		// Undo to seq 2: the node is gone, the value is 6.0.
		let session = DatabaseBackend::new();
		let at2 = load_at(&session, uri, &uuid, 2);
		{
			let l = at2.lock().unwrap();
			assert!(!l.graph.is_valid(new_id), "command 3 rolled back");
			let id = l
				.graph
				.node_ids()
				.into_iter()
				.find(|id| l.graph.get(*id).unwrap().behavior.type_id() == MATH)
				.unwrap();
			assert_eq!(
				l.graph.get(id).unwrap().core.standard_value("param_a_in", -1),
				NodeValue::Float(6.0)
			);
		}

		// Undo to seq 1: the value is back to the fixture default.
		let session = DatabaseBackend::new();
		let at1 = load_at(&session, uri, &uuid, 1);
		{
			let l = at1.lock().unwrap();
			assert_eq!(l.graph.node_count(), 12, "fixture node count");
			let id = l
				.graph
				.node_ids()
				.into_iter()
				.find(|id| l.graph.get(*id).unwrap().behavior.type_id() == MATH)
				.unwrap();
			assert_eq!(
				l.graph.get(id).unwrap().core.standard_value("param_a_in", -1),
				NodeValue::Float(2.5)
			);
		}

		// Undo to seq 0: an empty project.
		let session = DatabaseBackend::new();
		let at0 = load_at(&session, uri, &uuid, 0);
		{
			let l = at0.lock().unwrap();
			assert_eq!(l.graph.node_count(), 0, "empty project at seq 0");
		}

		// Out of range -> E_INVALID.
		let session = DatabaseBackend::new();
		assert_eq!(
			session
				.load_at(&StorageUri::parse(uri).unwrap(), &uuid, 99)
				.err()
				.unwrap()
				.code(),
			OAKSTORAGE_E_INVALID
		);
	});
}

/// Snapshot pruning keeps the newest [`SNAPSHOT_KEEP`] copies.
#[test]
fn pg_snapshot_pruning_keeps_three() {
	with_pg_uri("snapshot_pruning_keeps_three", |url, uri| {
		let backend = DatabaseBackend::new();

		with_config("Storage", "SnapshotIntervalSec", 0, || {
			let project = build_full_project();
			let uuid = uuid_of(&project);
			// 6 commands, each dirty-snapshotted.
			for i in 0..6i64 {
				{
					let mut p = project.lock().unwrap();
					let id = p.graph.node_ids()[0];
					p.graph.get_mut(id).unwrap().core.label = format!("step {i}");
				}
				save_project(&backend, &project, uri).unwrap();
			}
			let uuid_c = uuid.clone();
			let seqs = inspect_pg(url, move |conn| async move {
				let proj = project::Entity::find()
					.filter(project::Column::Uuid.eq(&uuid_c))
					.one(&conn)
					.await
					.unwrap()
					.unwrap();
				snapshot::Entity::find()
					.filter(snapshot::Column::ProjectId.eq(proj.id))
					.order_by_desc(snapshot::Column::CommandSeq)
					.all(&conn)
					.await
					.unwrap()
					.into_iter()
					.map(|s| s.command_seq)
					.collect::<Vec<i64>>()
			});
			assert_eq!(seqs.len() as u64, SNAPSHOT_KEEP, "only the newest {SNAPSHOT_KEEP}");
			assert_eq!(seqs[0], 6, "the newest survives");
		});
	});
}

/// Journal retention (`Storage/JournalRetentionDays`): rows older than
/// the window and covered by the newest snapshot are dropped; the head
/// stays reconstructible (snapshot + remaining rows).
#[test]
fn pg_journal_retention_truncation() {
	with_pg_uri("journal_retention_truncation", |url, uri| {
		let backend = DatabaseBackend::new();

		let project = build_full_project();
		let uuid = uuid_of(&project);
		// Command 1 (import) + command 2 (a value change).
		save_project(&backend, &project, uri).unwrap();
		{
			let mut p = project.lock().unwrap();
			let math_ids: Vec<NodeId> = p
				.graph
				.node_ids()
				.into_iter()
				.filter(|id| p.graph.get(*id).unwrap().behavior.type_id() == MATH)
				.collect();
			p.graph
				.get_mut(math_ids[0])
				.unwrap()
				.core
				.set_standard_value("param_a_in", -1, NodeValue::Float(3.25));
		}
		save_project(&backend, &project, uri).unwrap();
		// Snapshot at the head so rows ≤ 2 are covered.
		backend
			.snapshot(&StorageUri::parse(uri).unwrap(), &uuid)
			.unwrap();

		// Backdate every journal row two days, then save a third command
		// with a 1-day retention window.
		inspect_pg(url, |conn| async move {
			let old = chrono::Utc::now().naive_utc() - chrono::Duration::days(2);
			journal::Entity::update_many()
				.col_expr(journal::Column::At, sea_orm::sea_query::Expr::value(old))
				.exec(&conn)
				.await
				.unwrap();
		});
		with_config("Storage", "JournalRetentionDays", 1, || {
			{
				let mut p = project.lock().unwrap();
				let math_ids: Vec<NodeId> = p
					.graph
					.node_ids()
					.into_iter()
					.filter(|id| p.graph.get(*id).unwrap().behavior.type_id() == MATH)
					.collect();
				p.graph
					.get_mut(math_ids[0])
					.unwrap()
					.core
					.set_standard_value("param_a_in", -1, NodeValue::Float(4.5));
			}
			save_project(&backend, &project, uri).unwrap();
		});

		// Only the third command's rows survive.
		let uuid_c = uuid.clone();
		let (pid, rows) = inspect_pg(url, move |conn| async move {
			let proj = project::Entity::find()
				.filter(project::Column::Uuid.eq(&uuid_c))
				.one(&conn)
				.await
				.unwrap()
				.unwrap();
			let rows = journal::Entity::find()
				.filter(journal::Column::ProjectId.eq(proj.id))
				.all(&conn)
				.await
				.unwrap();
			(proj.id, rows)
		});
		let seqs: Vec<i64> = rows.iter().map(|r| r.seq).collect();
		assert!(!seqs.contains(&1) && !seqs.contains(&2), "old commands pruned: {seqs:?}");
		assert_eq!(seqs, vec![3], "only the fresh command remains");
		let _ = pid;

		// The head state is still correct (snapshot at seq 2 + command 3).
		let session = DatabaseBackend::new();
		let (_, loaded) = load_project(&session, &project_uri(uri, &uuid));
		{
			let l = loaded.lock().unwrap();
			let math_ids: Vec<NodeId> = l
				.graph
				.node_ids()
				.into_iter()
				.filter(|id| l.graph.get(*id).unwrap().behavior.type_id() == MATH)
				.collect();
			assert_eq!(
				l.graph.get(math_ids[0]).unwrap().core.standard_value("param_a_in", -1),
				NodeValue::Float(4.5)
			);
			assert_eq!(l.graph.node_count(), 12);
		}
	});
}

// ---------------------------------------------------------------------------
// Project-manager API surface
// ---------------------------------------------------------------------------

#[test]
fn pg_list_delete_duplicate_rename() {
	with_pg_uri("list_delete_duplicate_rename", |_url, uri| {
		let backend = DatabaseBackend::new();

		// Empty library lists nothing.
		assert!(backend.list_projects(&StorageUri::parse(uri).unwrap()).unwrap().is_empty());

		let alpha = save_named_project(&backend, uri, "Alpha");
		let beta = save_named_project(&backend, uri, "Beta");

		let list = backend.list_projects(&StorageUri::parse(uri).unwrap()).unwrap();
		assert_eq!(list.len(), 2, "two rows");
		// Most recently modified first.
		assert_eq!(list[0].name, "Beta");
		assert_eq!(list[1].name, "Alpha");
		assert_eq!(list[0].command_seq, 1);
		assert_eq!(list[0].schema_ver, oaknode::serializer::CURRENT_VERSION.0 as i32);

		// Rename (library metadata).
		backend
			.rename_project(&StorageUri::parse(uri).unwrap(), &alpha, "Alpha Renamed")
			.unwrap();
		let list = backend.list_projects(&StorageUri::parse(uri).unwrap()).unwrap();
		assert!(list.iter().any(|p| p.name == "Alpha Renamed"), "{list:?}");
		assert_eq!(
			backend
				.rename_project(&StorageUri::parse(uri).unwrap(), "{missing}", "X")
				.err()
				.unwrap()
				.code(),
			OAKSTORAGE_E_NOT_FOUND
		);

		// Duplicate: fresh uuid, default "(copy)" name, history copied.
		let copy = backend
			.duplicate_project(&StorageUri::parse(uri).unwrap(), &beta, None)
			.unwrap();
		assert_ne!(copy.uuid, beta, "fresh uuid");
		assert_eq!(copy.name, "Beta (copy)");
		assert_eq!(copy.command_seq, 1);
		let list = backend.list_projects(&StorageUri::parse(uri).unwrap()).unwrap();
		assert_eq!(list.len(), 3);
		let renamed_copy = backend
			.duplicate_project(&StorageUri::parse(uri).unwrap(), &beta, Some("Beta Clone"))
			.unwrap();
		assert_eq!(renamed_copy.name, "Beta Clone");
		assert_eq!(
			backend
				.duplicate_project(&StorageUri::parse(uri).unwrap(), "{missing}", None)
				.err()
				.unwrap()
				.code(),
			OAKSTORAGE_E_NOT_FOUND
		);

		// Delete.
		for uuid in [&alpha, &beta, &copy.uuid, &renamed_copy.uuid] {
			backend
				.delete_project(&StorageUri::parse(uri).unwrap(), uuid)
				.unwrap();
		}
		assert!(backend.list_projects(&StorageUri::parse(uri).unwrap()).unwrap().is_empty());
		assert_eq!(
			backend
				.delete_project(&StorageUri::parse(uri).unwrap(), "{missing}")
				.err()
				.unwrap()
				.code(),
			OAKSTORAGE_E_NOT_FOUND
		);
	});
}

/// Duplicating a full-feature project copies the whole history: the copy
/// loads identically under its own uuid and keeps the undo history.
#[test]
fn pg_duplicate_preserves_history() {
	with_pg_uri("duplicate_preserves_history", |_url, uri| {
		let backend = DatabaseBackend::new();

		let project = build_full_project();
		let uuid = uuid_of(&project);
		save_project(&backend, &project, uri).unwrap();
		{
			let mut p = project.lock().unwrap();
			let math_ids: Vec<NodeId> = p
				.graph
				.node_ids()
				.into_iter()
				.filter(|id| p.graph.get(*id).unwrap().behavior.type_id() == MATH)
				.collect();
			p.graph
				.get_mut(math_ids[0])
				.unwrap()
				.core
				.set_standard_value("param_a_in", -1, NodeValue::Float(6.0));
		}
		save_project(&backend, &project, uri).unwrap();

		let copy = backend
			.duplicate_project(&StorageUri::parse(uri).unwrap(), &uuid, None)
			.unwrap();
		assert_eq!(copy.command_seq, 2);

		// The copy loads through a fresh session, field-for-field (uuid is
		// fresh by design).
		let session = DatabaseBackend::new();
		let (loaded_uuid, loaded) = load_project(&session, &project_uri(uri, &copy.uuid));
		assert_eq!(loaded_uuid, copy.uuid);
		{
			let o = project.lock().unwrap();
			let l = loaded.lock().unwrap();
			assert_full_state(&o, &l);
		}

		// Undo history travels with the copy: load_at(1) on the copy gives
		// the pre-change state.
		let session = DatabaseBackend::new();
		let at1 = load_at(&session, uri, &copy.uuid, 1);
		{
			let l = at1.lock().unwrap();
			let math_ids: Vec<NodeId> = l
				.graph
				.node_ids()
				.into_iter()
				.filter(|id| l.graph.get(*id).unwrap().behavior.type_id() == MATH)
				.collect();
			assert_eq!(
				l.graph.get(math_ids[0]).unwrap().core.standard_value("param_a_in", -1),
				NodeValue::Float(2.5)
			);
		}
	});
}

/// Manager stats are derived from the node graph, not stored (plan §4).
#[test]
fn pg_project_stats_derived_from_graph() {
	with_pg_uri("project_stats_derived_from_graph", |_url, uri| {
		let backend = DatabaseBackend::new();

		let project = build_full_project();
		let uuid = uuid_of(&project);
		save_project(&backend, &project, uri).unwrap();

		let stats = backend
			.project_stats(&StorageUri::parse(uri).unwrap(), &uuid)
			.unwrap();
		assert_eq!(
			stats,
			ProjectStats {
				duration_ms: 6000,
				track_count: 1,
				clip_count: 2,
				footage_count: 2,
			}
		);
		// Same numbers derive_stats yields directly on the live project.
		let guard = project.lock().unwrap();
		assert_eq!(derive_stats(&guard), stats);
		assert_eq!(
			backend
				.project_stats(&StorageUri::parse(uri).unwrap(), "{missing}")
				.err()
				.unwrap()
				.code(),
			OAKSTORAGE_E_NOT_FOUND
		);
	});
}

#[test]
fn pg_export_and_import_round_trip() {
	with_pg_uri("export_and_import_round_trip", |_url, uri| {
		let dir = temp_dir("pg_xi");
		let backend = DatabaseBackend::new();

		let project = build_full_project();
		let uuid = uuid_of(&project);
		save_project(&backend, &project, uri).unwrap();

		// Export: .ove written from an in-memory assembly; the file backend
		// re-imports it byte-for-byte.
		let out = dir.join("exported.ove");
		let file = file_uri(&out);
		backend
			.export_to_file(
				&StorageUri::parse(uri).unwrap(),
				&uuid,
				&StorageUri::parse(&file).unwrap(),
			)
			.unwrap();
		assert!(out.exists(), ".ove written");
		let text = std::fs::read_to_string(&out).unwrap();
		assert!(text.starts_with("<project version=\"1\">"), "{text}");
		let file_backend = Registry::global()
			.resolve(&StorageUri::parse(&file).unwrap())
			.unwrap();
		let result = file_backend
			.load(&StorageUri::parse(&file).unwrap())
			.unwrap();
		assert_eq!(result.version_info, OAKSTORAGE_OK);
		let loaded = unsafe { project_arc(&result.project) }.unwrap();
		release(result.project);
		{
			let o = project.lock().unwrap();
			let l = loaded.lock().unwrap();
			assert_full_fields(&o, &l);
		}

		// Import: the .ove lands as a new library row under a fresh uuid;
		// importing it again yields a distinct row.
		let imported = backend
			.import_from_file(
				&StorageUri::parse(uri).unwrap(),
				&StorageUri::parse(&file).unwrap(),
			)
			.unwrap();
		assert_ne!(imported, uuid, "import gets a fresh uuid");
		let imported2 = backend
			.import_from_file(
				&StorageUri::parse(uri).unwrap(),
				&StorageUri::parse(&file).unwrap(),
			)
			.unwrap();
		assert_ne!(imported2, imported, "repeat imports are new rows");
		let list = backend.list_projects(&StorageUri::parse(uri).unwrap()).unwrap();
		assert_eq!(list.len(), 3, "original + two imports");
		let session = DatabaseBackend::new();
		let (imported_uuid, imported_proj) = load_project(&session, &project_uri(uri, &imported));
		assert_eq!(imported_uuid, imported);
		{
			let l = imported_proj.lock().unwrap();
			assert_eq!(l.graph.node_count(), 12);
			assert_eq!(
				l.settings.get("projectname").cloned(),
				Some("full-fixture".to_string())
			);
		}

		// Error paths: unknown project on export; non-file target; corrupt
		// file on import.
		assert_eq!(
			backend
				.export_to_file(
					&StorageUri::parse(uri).unwrap(),
					"{missing}",
					&StorageUri::parse(&file).unwrap(),
				)
				.err()
				.unwrap()
				.code(),
			OAKSTORAGE_E_NOT_FOUND
		);
		assert_eq!(
			backend
				.export_to_file(
					&StorageUri::parse(uri).unwrap(),
					&uuid,
					&StorageUri::parse("oakdb+sqlite:///tmp/x.db").unwrap(),
				)
				.err()
				.unwrap()
				.code(),
			OAKSTORAGE_E_INVALID
		);
		let corrupt = dir.join("corrupt.ove");
		std::fs::write(&corrupt, "<project><nodes><node></project>").unwrap();
		assert_eq!(
			backend
				.import_from_file(
					&StorageUri::parse(uri).unwrap(),
					&StorageUri::parse(&file_uri(&corrupt)).unwrap(),
				)
				.err()
				.unwrap()
				.code(),
			OAKSTORAGE_E_FORMAT
		);
	});
}

// ---------------------------------------------------------------------------
// Project selection (`?project=` vs default)
// ---------------------------------------------------------------------------

#[test]
fn pg_project_selection_via_query() {
	with_pg_uri("project_selection_via_query", |_url, uri| {
		let backend = DatabaseBackend::new();

		let a = save_named_project(&backend, uri, "A");
		let b = save_named_project(&backend, uri, "B");

		// Explicit uuid picks the right row regardless of recency.
		let session = DatabaseBackend::new();
		let (loaded_uuid, _) = load_project(&session, &project_uri(uri, &a));
		assert_eq!(loaded_uuid, a);

		// Default pick = most recently modified (B was written last).
		let session = DatabaseBackend::new();
		let (loaded_uuid, loaded) = load_project(&session, uri);
		assert_eq!(loaded_uuid, b);
		assert_eq!(
			loaded.lock().unwrap().settings.get("projectname").cloned(),
			Some("B".to_string())
		);

		// Unknown uuid -> E_NOT_FOUND; empty library -> E_NOT_FOUND.
		let session = DatabaseBackend::new();
		assert_eq!(
			session
				.load(&StorageUri::parse(&project_uri(uri, "{missing}")).unwrap())
				.err()
				.unwrap()
				.code(),
			OAKSTORAGE_E_NOT_FOUND
		);
	});
}