package channelserver

import (
	"fmt"
	"os"
	"os/exec"
	"path/filepath"
	"sort"
	"strings"
	"sync"
	"testing"

	"erupe-ce/server/channelserver/compression/nullcomp"
	"github.com/jmoiron/sqlx"
	_ "github.com/lib/pq"
)

var (
	testDBOnce        sync.Once
	testDB            *sqlx.DB
	testDBSetupFailed bool
)

// TestDBConfig holds the configuration for the test database
type TestDBConfig struct {
	Host     string
	Port     string
	User     string
	Password string
	DBName   string
}

// DefaultTestDBConfig returns the default test database configuration
// that matches docker-compose.test.yml
func DefaultTestDBConfig() *TestDBConfig {
	return &TestDBConfig{
		Host:     getEnv("TEST_DB_HOST", "localhost"),
		Port:     getEnv("TEST_DB_PORT", "5433"),
		User:     getEnv("TEST_DB_USER", "test"),
		Password: getEnv("TEST_DB_PASSWORD", "test"),
		DBName:   getEnv("TEST_DB_NAME", "erupe_test"),
	}
}

func getEnv(key, defaultValue string) string {
	if value := os.Getenv(key); value != "" {
		return value
	}
	return defaultValue
}

// SetupTestDB creates a connection to the test database and applies the schema.
// The schema is applied only once per test binary via sync.Once. Subsequent calls
// only TRUNCATE data for test isolation, avoiding expensive pg_restore + patch cycles.
func SetupTestDB(t *testing.T) *sqlx.DB {
	t.Helper()

	testDBOnce.Do(func() {
		config := DefaultTestDBConfig()
		connStr := fmt.Sprintf(
			"host=%s port=%s user=%s password=%s dbname=%s sslmode=disable",
			config.Host, config.Port, config.User, config.Password, config.DBName,
		)

		db, err := sqlx.Open("postgres", connStr)
		if err != nil {
			testDBSetupFailed = true
			return
		}

		if err := db.Ping(); err != nil {
			_ = db.Close()
			testDBSetupFailed = true
			return
		}

		// Clean the database and apply schema once
		CleanTestDB(t, db)
		ApplyTestSchema(t, db)

		testDB = db
	})

	if testDBSetupFailed || testDB == nil {
		t.Skipf("Test database not available. Run: docker compose -f docker/docker-compose.test.yml up -d")
		return nil
	}

	// Truncate all data for test isolation (schema stays intact)
	truncateAllTables(t, testDB)

	return testDB
}

// CleanTestDB drops all objects in the public schema to ensure a clean state
func CleanTestDB(t *testing.T, db *sqlx.DB) {
	t.Helper()

	// Drop and recreate the public schema to remove all objects (tables, types, sequences, etc.)
	_, err := db.Exec(`DROP SCHEMA public CASCADE; CREATE SCHEMA public;`)
	if err != nil {
		t.Logf("Warning: Failed to clean database: %v", err)
	}
}

// ApplyTestSchema applies the database schema from init.sql using pg_restore
func ApplyTestSchema(t *testing.T, db *sqlx.DB) {
	t.Helper()

	// Find the project root (where schemas/ directory is located)
	projectRoot := findProjectRoot(t)
	schemaPath := filepath.Join(projectRoot, "schemas", "init.sql")

	// Get the connection config
	config := DefaultTestDBConfig()

	// Use pg_restore to load the schema dump
	// The init.sql file is a pg_dump custom format, so we need pg_restore
	cmd := exec.Command("pg_restore",
		"-h", config.Host,
		"-p", config.Port,
		"-U", config.User,
		"-d", config.DBName,
		"--no-owner",
		"--no-acl",
		schemaPath,
	)
	cmd.Env = append(os.Environ(), fmt.Sprintf("PGPASSWORD=%s", config.Password))

	output, err := cmd.CombinedOutput()
	if err != nil {
		out := string(output)
		// pg_restore reports non-fatal warnings (version mismatches, already exists) as errors.
		// Only fail if we see no "errors ignored on restore" summary, which means a real failure.
		if !strings.Contains(out, "errors ignored on restore") {
			t.Fatalf("pg_restore failed: %v\n%s", err, out)
		}
		t.Logf("pg_restore completed with non-fatal warnings (ignored)")
	}

	// Apply the 9.2 update schema (init.sql bootstraps to 9.1.0)
	applyUpdateSchema(t, db, projectRoot)

	// Apply patch schemas in order
	applyPatchSchemas(t, db, projectRoot)
}

// applyUpdateSchema applies the 9.2 update schema that bridges init.sql (v9.1.0) to v9.2.0.
// It runs each statement individually to tolerate partial failures (e.g. role references).
func applyUpdateSchema(t *testing.T, db *sqlx.DB, projectRoot string) {
	t.Helper()

	updatePath := filepath.Join(projectRoot, "schemas", "update-schema", "9.2-update.sql")
	updateSQL, err := os.ReadFile(updatePath)
	if err != nil {
		t.Logf("Warning: Could not read 9.2 update schema: %v", err)
		return
	}

	// Strip the outer BEGIN/END transaction wrapper so we can run statements individually.
	content := string(updateSQL)
	content = strings.Replace(content, "BEGIN;", "", 1)
	// Remove trailing END; (last occurrence)
	if idx := strings.LastIndex(content, "END;"); idx >= 0 {
		content = content[:idx] + content[idx+4:]
	}

	// Split on semicolons and execute each statement, tolerating errors from
	// role references or already-applied changes.
	for _, stmt := range strings.Split(content, ";") {
		stmt = strings.TrimSpace(stmt)
		if stmt == "" {
			continue
		}
		if _, err := db.Exec(stmt); err != nil {
			// Silently ignore — these are expected for role mismatches, already-applied changes, etc.
		}
	}
}

// applyPatchSchemas applies all patch schema files in numeric order
func applyPatchSchemas(t *testing.T, db *sqlx.DB, projectRoot string) {
	t.Helper()

	patchDir := filepath.Join(projectRoot, "schemas", "patch-schema")
	entries, err := os.ReadDir(patchDir)
	if err != nil {
		t.Logf("Warning: Could not read patch-schema directory: %v", err)
		return
	}

	// Sort patch files numerically
	var patchFiles []string
	for _, entry := range entries {
		if !entry.IsDir() && strings.HasSuffix(entry.Name(), ".sql") {
			patchFiles = append(patchFiles, entry.Name())
		}
	}
	sort.Strings(patchFiles)

	// Apply each patch in its own transaction
	for _, filename := range patchFiles {
		patchPath := filepath.Join(patchDir, filename)
		patchSQL, err := os.ReadFile(patchPath)
		if err != nil {
			t.Logf("Warning: Failed to read patch file %s: %v", filename, err)
			continue
		}

		// Start a new transaction for each patch
		tx, err := db.Begin()
		if err != nil {
			t.Logf("Warning: Failed to start transaction for patch %s: %v", filename, err)
			continue
		}

		_, err = tx.Exec(string(patchSQL))
		if err != nil {
			_ = tx.Rollback()
			t.Logf("Warning: Failed to apply patch %s: %v", filename, err)
			// Continue with other patches even if one fails
		} else {
			_ = tx.Commit()
		}
	}
}

// findProjectRoot finds the project root directory by looking for the schemas directory
func findProjectRoot(t *testing.T) string {
	t.Helper()

	// Start from current directory and walk up
	dir, err := os.Getwd()
	if err != nil {
		t.Fatalf("Failed to get working directory: %v", err)
	}

	for {
		schemasPath := filepath.Join(dir, "schemas")
		if stat, err := os.Stat(schemasPath); err == nil && stat.IsDir() {
			return dir
		}

		parent := filepath.Dir(dir)
		if parent == dir {
			t.Fatal("Could not find project root (schemas directory not found)")
		}
		dir = parent
	}
}

// truncateAllTables truncates all tables in the public schema for test isolation.
func truncateAllTables(t *testing.T, db *sqlx.DB) {
	t.Helper()

	rows, err := db.Query("SELECT tablename FROM pg_tables WHERE schemaname = 'public'")
	if err != nil {
		t.Fatalf("Failed to list tables for truncation: %v", err)
	}
	defer rows.Close()

	var tables []string
	for rows.Next() {
		var name string
		if err := rows.Scan(&name); err != nil {
			t.Fatalf("Failed to scan table name: %v", err)
		}
		tables = append(tables, name)
	}

	if len(tables) > 0 {
		_, err := db.Exec("TRUNCATE " + strings.Join(tables, ", ") + " CASCADE")
		if err != nil {
			t.Fatalf("Failed to truncate tables: %v", err)
		}
	}
}

// TeardownTestDB is a no-op. The shared DB connection is reused across tests
// and closed automatically at process exit.
func TeardownTestDB(t *testing.T, db *sqlx.DB) {
	t.Helper()
}

// CreateTestUser creates a test user and returns the user ID
func CreateTestUser(t *testing.T, db *sqlx.DB, username string) uint32 {
	t.Helper()

	var userID uint32
	err := db.QueryRow(`
		INSERT INTO users (username, password, rights)
		VALUES ($1, 'test_password_hash', 0)
		RETURNING id
	`, username).Scan(&userID)

	if err != nil {
		t.Fatalf("Failed to create test user: %v", err)
	}

	return userID
}

// CreateTestCharacter creates a test character and returns the character ID
func CreateTestCharacter(t *testing.T, db *sqlx.DB, userID uint32, name string) uint32 {
	t.Helper()

	// Create minimal valid savedata (needs to be large enough for the game to parse)
	// The name is at offset 88, and various game mode pointers extend up to ~147KB for ZZ mode
	// We need at least 150KB to accommodate all possible pointer offsets
	saveData := make([]byte, 150000) // Large enough for all game modes
	copy(saveData[88:], append([]byte(name), 0x00)) // Name at offset 88 with null terminator

	// Import the nullcomp package for compression
	compressed, err := nullcomp.Compress(saveData)
	if err != nil {
		t.Fatalf("Failed to compress savedata: %v", err)
	}

	var charID uint32
	err = db.QueryRow(`
		INSERT INTO characters (user_id, is_female, is_new_character, name, unk_desc_string, gr, hr, weapon_type, last_login, savedata, decomyset, savemercenary)
		VALUES ($1, false, false, $2, '', 0, 0, 0, 0, $3, '', '')
		RETURNING id
	`, userID, name, compressed).Scan(&charID)

	if err != nil {
		t.Fatalf("Failed to create test character: %v", err)
	}

	return charID
}

// CreateTestGuild creates a test guild with the given leader and returns the guild ID
func CreateTestGuild(t *testing.T, db *sqlx.DB, leaderCharID uint32, name string) uint32 {
	t.Helper()

	tx, err := db.Begin()
	if err != nil {
		t.Fatalf("Failed to begin transaction: %v", err)
	}

	var guildID uint32
	err = tx.QueryRow(
		"INSERT INTO guilds (name, leader_id) VALUES ($1, $2) RETURNING id",
		name, leaderCharID,
	).Scan(&guildID)
	if err != nil {
		_ = tx.Rollback()
		t.Fatalf("Failed to create test guild: %v", err)
	}

	_, err = tx.Exec(
		"INSERT INTO guild_characters (guild_id, character_id) VALUES ($1, $2)",
		guildID, leaderCharID,
	)
	if err != nil {
		_ = tx.Rollback()
		t.Fatalf("Failed to add leader to guild: %v", err)
	}

	if err := tx.Commit(); err != nil {
		t.Fatalf("Failed to commit guild creation: %v", err)
	}

	return guildID
}

// SetTestDB assigns a database to a Server and initializes all repositories.
// Use this in integration tests instead of setting s.server.db directly.
func SetTestDB(s *Server, db *sqlx.DB) {
	s.db = db
	s.charRepo = NewCharacterRepository(db)
	s.guildRepo = NewGuildRepository(db)
	s.userRepo = NewUserRepository(db)
	s.gachaRepo = NewGachaRepository(db)
	s.houseRepo = NewHouseRepository(db)
	s.festaRepo = NewFestaRepository(db)
	s.towerRepo = NewTowerRepository(db)
	s.rengokuRepo = NewRengokuRepository(db)
	s.mailRepo = NewMailRepository(db)
}