package integration_test

import (
	"context"
	"database/sql"
	"errors"
	"fmt"
	"io/fs"
	"path/filepath"
	"testing"

	_ "modernc.org/sqlite"
	"sub2api-cn-relay-manager/internal/store/migrations"
	"sub2api-cn-relay-manager/internal/store/sqlite"
)

func TestStoreInitCreatesRequiredTables(t *testing.T) {
	store := openTestStore(t)
	defer closeTestStore(t, store)

	for _, table := range []string{"hosts", "packs", "providers"} {
		if !tableExists(t, store.SQLDB(), table) {
			t.Fatalf("table %q does not exist after store initialization", table)
		}
	}
}

func TestStoreInitEnforcesUniqueConstraints(t *testing.T) {
	ctx := context.Background()
	store := openTestStore(t)
	defer closeTestStore(t, store)

	packID, err := store.Packs().Create(ctx, sqlite.Pack{
		PackID:   "openai-cn-pack",
		Version:  "1.0.0",
		Checksum: "checksum-1",
	})
	if err != nil {
		t.Fatalf("Packs().Create() error = %v", err)
	}

	provider := sqlite.Provider{
		PackID:      packID,
		ProviderID:  "deepseek",
		DisplayName: "DeepSeek",
		BaseURL:     "https://api.deepseek.com",
		Platform:    "openai",
	}

	if _, err := store.Providers().Create(ctx, provider); err != nil {
		t.Fatalf("Providers().Create() first call error = %v", err)
	}

	if _, err := store.Providers().Create(ctx, provider); err == nil {
		t.Fatal("Providers().Create() second call error = nil, want unique constraint failure")
	}
}

func TestStoreInitEnforcesProviderForeignKey(t *testing.T) {
	ctx := context.Background()
	store := openTestStore(t)
	defer closeTestStore(t, store)

	_, err := store.Providers().Create(ctx, sqlite.Provider{
		PackID:      9999,
		ProviderID:  "ghost",
		DisplayName: "Ghost",
		BaseURL:     "https://ghost.example.com",
		Platform:    "openai",
	})
	if err == nil {
		t.Fatal("Providers().Create() error = nil, want foreign key failure")
	}
}

func TestStoreInitRollsBackTransaction(t *testing.T) {
	ctx := context.Background()
	store := openTestStore(t)
	defer closeTestStore(t, store)

	wantErr := errors.New("force rollback")

	err := store.WithTx(ctx, func(queries *sqlite.Queries) error {
		_, err := queries.Hosts.Create(ctx, sqlite.Host{
			HostID:              "host-1",
			BaseURL:             "https://host.example.com",
			HostVersion:         "0.1.126",
			CapabilityProbeJSON: `{"supports_batch_accounts":true}`,
		})
		if err != nil {
			return err
		}

		return wantErr
	})
	if !errors.Is(err, wantErr) {
		t.Fatalf("WithTx() error = %v, want %v", err, wantErr)
	}

	if got := countRows(t, store.SQLDB(), "hosts"); got != 0 {
		t.Fatalf("hosts row count after rollback = %d, want 0", got)
	}
}

func TestStoreInitRecordsMigrationLedgerOnce(t *testing.T) {
	dbPath := filepath.Join(t.TempDir(), "state.db")
	dsn := fmt.Sprintf("file:%s?_busy_timeout=5000", filepath.ToSlash(dbPath))
	wantMigrations := migrationCount(t)

	store1, err := sqlite.Open(context.Background(), dsn)
	if err != nil {
		t.Fatalf("first sqlite.Open() error = %v", err)
	}
	if got := countRows(t, store1.SQLDB(), "schema_migrations"); got != wantMigrations {
		t.Fatalf("schema_migrations row count after first open = %d, want %d", got, wantMigrations)
	}
	if err := store1.Close(); err != nil {
		t.Fatalf("first store.Close() error = %v", err)
	}

	store2, err := sqlite.Open(context.Background(), dsn)
	if err != nil {
		t.Fatalf("second sqlite.Open() error = %v", err)
	}
	defer closeTestStore(t, store2)

	if got := countRows(t, store2.SQLDB(), "schema_migrations"); got != wantMigrations {
		t.Fatalf("schema_migrations row count after second open = %d, want %d", got, wantMigrations)
	}
}

func TestStoreAppliesLatestMigration(t *testing.T) {
	store := openTestStore(t)
	defer closeTestStore(t, store)

	for _, table := range []string{
		"import_runs",
		"import_run_items",
		"import_run_item_events",
		"logical_groups",
		"logical_group_models",
		"logical_group_routes",
		"logical_group_route_models",
		"route_decision_logs",
		"route_failover_events",
		"route_sticky_audit",
		"provider_accounts",
	} {
		if !tableExists(t, store.SQLDB(), table) {
			t.Fatalf("table %q does not exist after latest migration", table)
		}
	}

	for _, column := range []string{
		"host_id",
		"subscription_users_json",
		"subscription_days",
		"probe_api_key",
	} {
		if !tableColumnExists(t, store.SQLDB(), "import_runs", column) {
			t.Fatalf("column %q missing from import_runs", column)
		}
	}

	for _, column := range []string{
		"api_key_fingerprint",
		"canonical_model_families_json",
		"matched_account_state",
		"account_resolution",
		"provision_reused",
		"reused_from_provider_id",
		"reused_from_account_id",
		"lease_owner",
		"lease_until",
	} {
		if !tableColumnExists(t, store.SQLDB(), "import_run_items", column) {
			t.Fatalf("column %q missing from import_run_items", column)
		}
	}

	for _, column := range []string{
		"logical_group_id",
		"display_name",
		"route_policy",
		"sticky_mode",
		"conversation_ttl_seconds",
		"user_model_ttl_seconds",
		"failover_threshold",
		"cooldown_seconds",
	} {
		if !tableColumnExists(t, store.SQLDB(), "logical_groups", column) {
			t.Fatalf("column %q missing from logical_groups", column)
		}
	}

	for _, column := range []string{
		"logical_group_id",
		"public_model",
		"status",
	} {
		if !tableColumnExists(t, store.SQLDB(), "logical_group_models", column) {
			t.Fatalf("column %q missing from logical_group_models", column)
		}
	}

	for _, column := range []string{
		"route_id",
		"logical_group_id",
		"priority",
		"weight",
		"shadow_group_id",
		"shadow_host_id",
		"upstream_base_url_hint",
		"cooldown_until",
	} {
		if !tableColumnExists(t, store.SQLDB(), "logical_group_routes", column) {
			t.Fatalf("column %q missing from logical_group_routes", column)
		}
	}

	for _, column := range []string{
		"route_id",
		"public_model",
		"shadow_model",
		"status",
	} {
		if !tableColumnExists(t, store.SQLDB(), "logical_group_route_models", column) {
			t.Fatalf("column %q missing from logical_group_route_models", column)
		}
	}

	for _, column := range []string{
		"request_id",
		"logical_group_id",
		"public_model",
		"sticky_key",
		"sticky_hit",
		"selected_route_id",
		"selected_shadow_group_id",
		"fallback_used",
		"upstream_status",
		"latency_ms",
	} {
		if !tableColumnExists(t, store.SQLDB(), "route_decision_logs", column) {
			t.Fatalf("column %q missing from route_decision_logs", column)
		}
	}

	for _, column := range []string{
		"request_id",
		"logical_group_id",
		"public_model",
		"from_route_id",
		"to_route_id",
		"reason",
		"failure_count",
	} {
		if !tableColumnExists(t, store.SQLDB(), "route_failover_events", column) {
			t.Fatalf("column %q missing from route_failover_events", column)
		}
	}

	for _, column := range []string{
		"sticky_key",
		"sticky_key_type",
		"logical_group_id",
		"public_model",
		"route_id",
		"action",
		"expires_at",
	} {
		if !tableColumnExists(t, store.SQLDB(), "route_sticky_audit", column) {
			t.Fatalf("column %q missing from route_sticky_audit", column)
		}
	}

	for _, column := range []string{
		"host_id",
		"provider_id",
		"route_id",
		"shadow_group_id",
		"host_account_id",
		"key_fingerprint",
		"account_status",
		"last_probe_status",
		"last_probe_at",
		"disabled_reason",
	} {
		if !tableColumnExists(t, store.SQLDB(), "provider_accounts", column) {
			t.Fatalf("column %q missing from provider_accounts", column)
		}
	}
}

func TestStoreInitEnforcesLogicalRoutingConstraints(t *testing.T) {
	ctx := context.Background()
	store := openTestStore(t)
	defer closeTestStore(t, store)

	db := store.SQLDB()
	mustExecSQL(t, db, `
INSERT INTO logical_groups (
    logical_group_id,
    display_name,
    status
) VALUES (?, ?, ?)`,
		"gpt-shared",
		"GPT Shared",
		"active",
	)

	if _, err := db.ExecContext(ctx, `
INSERT INTO logical_groups (
    logical_group_id,
    display_name,
    status
) VALUES (?, ?, ?)`,
		"gpt-shared",
		"GPT Shared Duplicate",
		"active",
	); err == nil {
		t.Fatal("duplicate logical_group_id insert error = nil, want unique constraint failure")
	}

	mustExecSQL(t, db, `
INSERT INTO logical_group_models (
    logical_group_id,
    public_model
) VALUES (?, ?)`,
		"gpt-shared",
		"gpt-5.4",
	)

	if _, err := db.ExecContext(ctx, `
INSERT INTO logical_group_models (
    logical_group_id,
    public_model
) VALUES (?, ?)`,
		"gpt-shared",
		"gpt-5.4",
	); err == nil {
		t.Fatal("duplicate logical_group_models insert error = nil, want unique constraint failure")
	}

	if _, err := db.ExecContext(ctx, `
INSERT INTO logical_group_routes (
    route_id,
    logical_group_id,
    name,
    status,
    priority,
    shadow_group_id,
    shadow_host_id
) VALUES (?, ?, ?, ?, ?, ?, ?)`,
		"route-missing-group",
		"missing-group",
		"Missing Group Route",
		"active",
		10,
		"shadow-group-a",
		"shadow-host-a",
	); err == nil {
		t.Fatal("logical_group_routes missing group error = nil, want foreign key failure")
	}

	mustExecSQL(t, db, `
INSERT INTO logical_group_routes (
    route_id,
    logical_group_id,
    name,
    status,
    priority,
    shadow_group_id,
    shadow_host_id
) VALUES (?, ?, ?, ?, ?, ?, ?)`,
		"route-asxs",
		"gpt-shared",
		"ASXS",
		"active",
		10,
		"gpt-shared__asxs",
		"remote43",
	)

	if _, err := db.ExecContext(ctx, `
INSERT INTO logical_group_route_models (
    route_id,
    public_model,
    shadow_model
) VALUES (?, ?, ?)`,
		"missing-route",
		"gpt-5.4",
		"gpt-5.4",
	); err == nil {
		t.Fatal("logical_group_route_models missing route error = nil, want foreign key failure")
	}

	mustExecSQL(t, db, `
INSERT INTO logical_group_route_models (
    route_id,
    public_model,
    shadow_model
) VALUES (?, ?, ?)`,
		"route-asxs",
		"gpt-5.4",
		"gpt-5.4",
	)

	if _, err := db.ExecContext(ctx, `
INSERT INTO logical_group_route_models (
    route_id,
    public_model,
    shadow_model
) VALUES (?, ?, ?)`,
		"route-asxs",
		"gpt-5.4",
		"gpt-5.4-alt",
	); err == nil {
		t.Fatal("duplicate logical_group_route_models insert error = nil, want unique constraint failure")
	}
}

func TestStoreInitBackfillsLedgerForCompletePreLedgerSchema(t *testing.T) {
	dbPath := filepath.Join(t.TempDir(), "state.db")
	dsn := fmt.Sprintf("file:%s?_busy_timeout=5000", filepath.ToSlash(dbPath))
	wantMigrations := migrationCount(t)

	rawDB := openRawSQLiteDB(t, dsn)
	createLegacy0001Schema(t, rawDB)
	closeRawSQLiteDB(t, rawDB)

	store, err := sqlite.Open(context.Background(), dsn)
	if err != nil {
		t.Fatalf("sqlite.Open() on complete pre-ledger schema error = %v", err)
	}
	defer closeTestStore(t, store)

	if got := countRows(t, store.SQLDB(), "schema_migrations"); got != wantMigrations {
		t.Fatalf("schema_migrations row count after backfill = %d, want %d", got, wantMigrations)
	}
}

func TestStoreInitFailsWhenPreLedgerSchemaIsPartial(t *testing.T) {
	dbPath := filepath.Join(t.TempDir(), "state.db")
	dsn := fmt.Sprintf("file:%s?_busy_timeout=5000", filepath.ToSlash(dbPath))

	rawDB := openRawSQLiteDB(t, dsn)
	mustExec(t, rawDB, `
CREATE TABLE hosts (
    id INTEGER PRIMARY KEY AUTOINCREMENT,
    host_id TEXT NOT NULL UNIQUE,
    base_url TEXT NOT NULL,
    host_version TEXT NOT NULL,
    capability_probe_json TEXT NOT NULL DEFAULT '{}',
    created_at TEXT NOT NULL DEFAULT CURRENT_TIMESTAMP
)`)
	closeRawSQLiteDB(t, rawDB)

	store, err := sqlite.Open(context.Background(), dsn)
	if err == nil {
		closeTestStore(t, store)
		t.Fatal("sqlite.Open() error = nil, want partial pre-ledger schema failure")
	}
}

func openTestStore(t *testing.T) *sqlite.DB {
	t.Helper()

	dbPath := filepath.Join(t.TempDir(), "state.db")
	dsn := fmt.Sprintf("file:%s?_busy_timeout=5000&_pragma=foreign_keys(0)", filepath.ToSlash(dbPath))

	store, err := sqlite.Open(context.Background(), dsn)
	if err != nil {
		t.Fatalf("sqlite.Open() error = %v", err)
	}

	return store
}

func openRawSQLiteDB(t *testing.T, dsn string) *sql.DB {
	t.Helper()

	db, err := sql.Open("sqlite", dsn)
	if err != nil {
		t.Fatalf("sql.Open() error = %v", err)
	}

	if err := db.PingContext(context.Background()); err != nil {
		t.Fatalf("raw db PingContext() error = %v", err)
	}

	return db
}

func closeRawSQLiteDB(t *testing.T, db *sql.DB) {
	t.Helper()

	if err := db.Close(); err != nil {
		t.Fatalf("raw db Close() error = %v", err)
	}
}

func migrationCount(t *testing.T) int {
	t.Helper()

	names, err := fs.Glob(migrations.Files, "*.sql")
	if err != nil {
		t.Fatalf("fs.Glob(migrations.Files) error = %v", err)
	}
	return len(names)
}

func createLegacy0001Schema(t *testing.T, db *sql.DB) {
	t.Helper()

	mustExec(t, db, `
CREATE TABLE hosts (
    id INTEGER PRIMARY KEY AUTOINCREMENT,
    host_id TEXT NOT NULL UNIQUE,
    base_url TEXT NOT NULL,
    host_version TEXT NOT NULL,
    capability_probe_json TEXT NOT NULL DEFAULT '{}',
    created_at TEXT NOT NULL DEFAULT CURRENT_TIMESTAMP
)`)
	mustExec(t, db, `
CREATE TABLE packs (
    id INTEGER PRIMARY KEY AUTOINCREMENT,
    pack_id TEXT NOT NULL UNIQUE,
    version TEXT NOT NULL,
    checksum TEXT NOT NULL,
    installed_at TEXT NOT NULL DEFAULT CURRENT_TIMESTAMP
)`)
	mustExec(t, db, `
CREATE TABLE providers (
    id INTEGER PRIMARY KEY AUTOINCREMENT,
    pack_id INTEGER NOT NULL,
    provider_id TEXT NOT NULL,
    display_name TEXT NOT NULL,
    base_url TEXT NOT NULL,
    platform TEXT NOT NULL,
    created_at TEXT NOT NULL DEFAULT CURRENT_TIMESTAMP,
    CONSTRAINT fk_providers_pack
        FOREIGN KEY (pack_id)
        REFERENCES packs(id)
        ON DELETE CASCADE,
    CONSTRAINT uq_providers_pack_provider
        UNIQUE (pack_id, provider_id)
)`)
}

func mustExec(t *testing.T, db *sql.DB, statement string) {
	t.Helper()

	if _, err := db.ExecContext(context.Background(), statement); err != nil {
		t.Fatalf("ExecContext() error = %v", err)
	}
}

func mustExecSQL(t *testing.T, db *sql.DB, statement string, args ...any) {
	t.Helper()

	if _, err := db.ExecContext(context.Background(), statement, args...); err != nil {
		t.Fatalf("ExecContext() error = %v", err)
	}
}

func closeTestStore(t *testing.T, store *sqlite.DB) {
	t.Helper()

	if err := store.Close(); err != nil {
		t.Fatalf("store.Close() error = %v", err)
	}
}

func tableExists(t *testing.T, db *sql.DB, table string) bool {
	t.Helper()

	var name string
	err := db.QueryRowContext(
		context.Background(),
		"SELECT name FROM sqlite_master WHERE type = 'table' AND name = ?",
		table,
	).Scan(&name)
	if errors.Is(err, sql.ErrNoRows) {
		return false
	}
	if err != nil {
		t.Fatalf("tableExists(%q) query error = %v", table, err)
	}

	return name == table
}

func countRows(t *testing.T, db *sql.DB, table string) int {
	t.Helper()

	var count int
	query := fmt.Sprintf("SELECT COUNT(*) FROM %s", table)
	if err := db.QueryRowContext(context.Background(), query).Scan(&count); err != nil {
		t.Fatalf("countRows(%q) query error = %v", table, err)
	}

	return count
}

func tableColumnExists(t *testing.T, db *sql.DB, table, column string) bool {
	t.Helper()

	rows, err := db.QueryContext(context.Background(), "PRAGMA table_info("+table+")")
	if err != nil {
		t.Fatalf("table_info(%q) query error = %v", table, err)
	}
	defer rows.Close()

	for rows.Next() {
		var (
			cid        int
			name       string
			columnType string
			notNull    int
			defaultVal sql.NullString
			pk         int
		)
		if err := rows.Scan(&cid, &name, &columnType, &notNull, &defaultVal, &pk); err != nil {
			t.Fatalf("table_info(%q) scan error = %v", table, err)
		}
		if name == column {
			return true
		}
	}
	if err := rows.Err(); err != nil {
		t.Fatalf("table_info(%q) rows error = %v", table, err)
	}
	return false
}