package database

import (
	"fmt"
	"net/url"
	"os"
	"path/filepath"
	"testing"
	"time"

	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
	"gorm.io/driver/postgres"
	"gorm.io/driver/sqlite"
	"gorm.io/gorm"
	"gorm.io/gorm/logger"
)

const captainSkillMigrationBaseline = `
CREATE TABLE accounts (id INTEGER PRIMARY KEY);
CREATE TABLE captain_assistants (id INTEGER PRIMARY KEY, account_id INTEGER NOT NULL);
CREATE TABLE captain_skills (id INTEGER PRIMARY KEY, account_id INTEGER NOT NULL);
CREATE TABLE captain_assistant_skills (
  id INTEGER PRIMARY KEY,
  account_id INTEGER NOT NULL REFERENCES accounts(id) ON DELETE CASCADE,
  assistant_id INTEGER NOT NULL REFERENCES captain_assistants(id) ON DELETE CASCADE,
  skill_id INTEGER NOT NULL REFERENCES captain_skills(id) ON DELETE CASCADE,
  created_at TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
  UNIQUE (assistant_id, skill_id)
);
CREATE INDEX idx_captain_assistant_skills_account ON captain_assistant_skills(account_id);
CREATE INDEX idx_captain_assistant_skills_skill ON captain_assistant_skills(skill_id);
`

func captainSkillMigrationDir(t *testing.T, dialect string) string {
	t.Helper()
	dir := t.TempDir()
	for _, direction := range []string{"up", "down"} {
		require.NoError(t, os.WriteFile(filepath.Join(dir, "000080_baseline."+direction+".sql"), []byte("SELECT 1;"), 0o600))
	}
	for _, direction := range []string{"up", "down"} {
		name := "000081_enforce_captain_skill_tenant_consistency." + direction + ".sql"
		parts := []string{"..", "..", "migrations"}
		if dialect != "" {
			parts = append(parts, dialect)
		}
		data, err := os.ReadFile(filepath.Join(append(parts, name)...))
		require.NoError(t, err)
		require.NoError(t, os.WriteFile(filepath.Join(dir, name), data, 0o600))
	}
	return dir
}

func TestCaptainSkillSQLiteMigrationRoundTrip(t *testing.T) {
	dbPath := filepath.Join(t.TempDir(), "captain-skill.db")
	dbURL := "sqlite3://" + dbPath + "?_foreign_keys=on"
	db, err := gorm.Open(sqlite.Open(dbPath+"?_foreign_keys=on"), &gorm.Config{Logger: logger.Default.LogMode(logger.Silent)})
	require.NoError(t, err)
	sqlDB, err := db.DB()
	require.NoError(t, err)
	sqlDB.SetMaxOpenConns(1)
	t.Cleanup(func() { _ = sqlDB.Close() })
	require.NoError(t, db.Exec(captainSkillMigrationBaseline).Error)
	require.NoError(t, db.Exec("INSERT INTO accounts VALUES (1), (2); INSERT INTO captain_assistants VALUES (1, 1), (2, 2); INSERT INTO captain_skills VALUES (1, 1), (2, 2)").Error)

	migrations := captainSkillMigrationDir(t, "sqlite")
	require.NoError(t, ForceVersion(dbURL, migrations, 80))
	require.NoError(t, MigrateSteps(dbURL, migrations, 1))
	version, dirty, err := CurrentVersion(dbURL, migrations)
	require.NoError(t, err)
	assert.Equal(t, uint(81), version)
	assert.False(t, dirty)

	require.NoError(t, db.Exec("INSERT INTO captain_assistant_skills(id, account_id, assistant_id, skill_id) VALUES (1, 1, 1, 1)").Error)
	assert.Error(t, db.Exec("INSERT INTO captain_assistant_skills(id, account_id, assistant_id, skill_id) VALUES (2, 1, 2, 1)").Error)
	assert.Error(t, db.Exec("INSERT INTO captain_assistant_skills(id, account_id, assistant_id, skill_id) VALUES (3, 1, 1, 2)").Error)

	require.NoError(t, MigrateSteps(dbURL, migrations, -1))
	version, dirty, err = CurrentVersion(dbURL, migrations)
	require.NoError(t, err)
	assert.Equal(t, uint(80), version)
	assert.False(t, dirty)
	require.NoError(t, db.Exec("INSERT INTO captain_assistant_skills(id, account_id, assistant_id, skill_id) VALUES (2, 1, 2, 1), (3, 1, 1, 2)").Error)
	assert.False(t, db.Migrator().HasIndex("captain_assistants", "idx_captain_assistants_account_id_id"))
	assert.False(t, db.Migrator().HasIndex("captain_skills", "idx_captain_skills_account_id_id"))
}

func openCaptainMigrationPostgres(t *testing.T) (*gorm.DB, string) {
	t.Helper()
	dsn := os.Getenv("GOCHAT_TEST_DB_URL")
	if dsn == "" {
		dsn = "postgres://postgres:postgres@localhost:5432/gochat_test?sslmode=disable"
	}
	admin, err := gorm.Open(postgres.Open(dsn), &gorm.Config{Logger: logger.Default.LogMode(logger.Silent)})
	require.NoError(t, err)
	adminDB, err := admin.DB()
	require.NoError(t, err)
	t.Cleanup(func() { _ = adminDB.Close() })

	schema := fmt.Sprintf("captain_skill_migration_%d", time.Now().UnixNano())
	require.NoError(t, admin.Exec("CREATE SCHEMA "+schema).Error)
	t.Cleanup(func() { _ = admin.Exec("DROP SCHEMA " + schema + " CASCADE").Error })
	migrationURL, err := url.Parse(dsn)
	require.NoError(t, err)
	require.NotEmpty(t, migrationURL.Scheme, "GOCHAT_TEST_DB_URL must be a PostgreSQL URL")
	query := migrationURL.Query()
	query.Set("search_path", schema)
	migrationURL.RawQuery = query.Encode()

	db, err := gorm.Open(postgres.Open(migrationURL.String()), &gorm.Config{Logger: logger.Default.LogMode(logger.Silent)})
	require.NoError(t, err)
	sqlDB, err := db.DB()
	require.NoError(t, err)
	sqlDB.SetMaxOpenConns(1)
	t.Cleanup(func() { _ = sqlDB.Close() })
	require.NoError(t, db.Exec(captainSkillMigrationBaseline).Error)
	return db, migrationURL.String()
}

func runCaptainSkillMigration(t *testing.T, fn func() error) {
	t.Helper()
	require.NoError(t, withSanitizedPQEnvironment(fn))
}

func TestCaptainSkillPostgresMigrationRoundTrip(t *testing.T) {
	if os.Getenv("GOCHAT_TEST_DB") == "sqlite" {
		t.Skip("PostgreSQL migration test")
	}
	db, dbURL := openCaptainMigrationPostgres(t)
	require.NoError(t, db.Exec("INSERT INTO accounts VALUES (1), (2); INSERT INTO captain_assistants VALUES (1, 1), (2, 2); INSERT INTO captain_skills VALUES (1, 1), (2, 2)").Error)
	migrations := captainSkillMigrationDir(t, "")
	runCaptainSkillMigration(t, func() error { return ForceVersion(dbURL, migrations, 80) })
	runCaptainSkillMigration(t, func() error { return MigrateSteps(dbURL, migrations, 1) })

	require.NoError(t, db.Exec("INSERT INTO captain_assistant_skills(id, account_id, assistant_id, skill_id) VALUES (1, 1, 1, 1)").Error)
	assert.Error(t, db.Exec("INSERT INTO captain_assistant_skills(id, account_id, assistant_id, skill_id) VALUES (2, 1, 2, 1)").Error)
	assert.Error(t, db.Exec("INSERT INTO captain_assistant_skills(id, account_id, assistant_id, skill_id) VALUES (3, 1, 1, 2)").Error)

	runCaptainSkillMigration(t, func() error { return MigrateSteps(dbURL, migrations, -1) })
	require.NoError(t, db.Exec("INSERT INTO captain_assistant_skills(id, account_id, assistant_id, skill_id) VALUES (2, 1, 2, 1), (3, 1, 1, 2)").Error)
	var count int64
	require.NoError(t, db.Raw("SELECT count(*) FROM pg_indexes WHERE schemaname = current_schema() AND indexname IN ('idx_captain_assistants_account_id_id', 'idx_captain_skills_account_id_id')").Scan(&count).Error)
	assert.Zero(t, count)
}

func TestCaptainSkillPostgresMigrationRejectsDirtyBindingsAtomically(t *testing.T) {
	if os.Getenv("GOCHAT_TEST_DB") == "sqlite" {
		t.Skip("PostgreSQL migration test")
	}
	db, dbURL := openCaptainMigrationPostgres(t)
	require.NoError(t, db.Exec("INSERT INTO accounts VALUES (1), (2); INSERT INTO captain_assistants VALUES (1, 1), (2, 2); INSERT INTO captain_skills VALUES (1, 1), (2, 2); INSERT INTO captain_assistant_skills(id, account_id, assistant_id, skill_id) VALUES (1, 1, 2, 1)").Error)
	migrations := captainSkillMigrationDir(t, "")
	runCaptainSkillMigration(t, func() error { return ForceVersion(dbURL, migrations, 80) })
	err := withSanitizedPQEnvironment(func() error { return MigrateSteps(dbURL, migrations, 1) })
	require.Error(t, err)

	var count int64
	require.NoError(t, db.Table("captain_assistant_skills").Count(&count).Error)
	assert.Equal(t, int64(1), count)
	require.NoError(t, db.Raw("SELECT count(*) FROM pg_indexes WHERE schemaname = current_schema() AND indexname IN ('idx_captain_assistants_account_id_id', 'idx_captain_skills_account_id_id')").Scan(&count).Error)
	assert.Zero(t, count)
	require.NoError(t, db.Raw("SELECT count(*) FROM pg_constraint WHERE connamespace = current_schema()::regnamespace AND conname IN ('fk_captain_assistant_skills_assistant_tenant', 'fk_captain_assistant_skills_skill_tenant')").Scan(&count).Error)
	assert.Zero(t, count)
	version, dirty, versionErr := CurrentVersion(dbURL, migrations)
	require.NoError(t, versionErr)
	assert.Equal(t, uint(81), version)
	assert.True(t, dirty)
}