package config

import (
	"fmt"
	"testing"
	"time"

	"github.com/stretchr/testify/assert"
)

func TestValidate_ValidConfig(t *testing.T) {
	cfg := &Config{
		Server: ServerConfig{Host: "localhost", Port: 8080, Mode: "debug"},
		Database: DatabaseConfig{
			DSN: "postgres://gochat:secret@localhost:5432/gochat_db?sslmode=disable",
		},
		Redis: RedisConfig{
			DSN: "redis://localhost:6379",
		},
		JWT: JWTConfig{
			Secret:             "test-secret-key-min-32-chars!!",
			ExpiryHours:        24,
			RefreshExpiryHours: 168,
		},
		Log:    LogConfig{Level: "info", Format: "json"},
		Worker: WorkerConfig{Concurrency: 4, BlockTimeoutS: 5, SweepIntervalS: 30},
		OAuth:  OAuthConfig{},
		Search: SearchConfig{Engine: "meilisearch", Host: "http://localhost:7700", IndexPrefix: "gochat_", TimeoutSeconds: 5},
	}

	err := Validate(cfg)
	assert.NoError(t, err)
}

func TestValidate_InvalidPort(t *testing.T) {
	cfg := &Config{
		Server:   ServerConfig{Host: "localhost", Port: 0, Mode: "debug"},
		Database: DatabaseConfig{DSN: "postgres://user@localhost:5432/db?sslmode=disable"},
		Redis:    RedisConfig{DSN: "redis://localhost:6379"},
		JWT:      JWTConfig{Secret: "test-secret-key-min-32-chars!!"},
	}

	err := Validate(cfg)
	assert.Error(t, err)
	assert.Contains(t, err.Error(), "invalid server port")
}

func TestValidate_InvalidMode(t *testing.T) {
	cfg := &Config{
		Server:   ServerConfig{Host: "localhost", Port: 8080, Mode: "invalid"},
		Database: DatabaseConfig{DSN: "postgres://user@localhost:5432/db?sslmode=disable"},
		Redis:    RedisConfig{DSN: "redis://localhost:6379"},
		JWT:      JWTConfig{Secret: "test-secret-key-min-32-chars!!"},
	}

	err := Validate(cfg)
	assert.Error(t, err)
	assert.Contains(t, err.Error(), "invalid server mode")
}

func TestValidate_MissingDBDSN(t *testing.T) {
	cfg := &Config{
		Server:   ServerConfig{Host: "localhost", Port: 8080, Mode: "debug"},
		Database: DatabaseConfig{},
		Redis:    RedisConfig{DSN: "redis://localhost:6379"},
		JWT:      JWTConfig{Secret: "test-secret-key-min-32-chars!!"},
	}

	err := Validate(cfg)
	assert.Error(t, err)
	assert.Contains(t, err.Error(), "database DSN is required")
}

func TestValidate_InvalidDBDSN(t *testing.T) {
	cfg := &Config{
		Server:   ServerConfig{Host: "localhost", Port: 8080, Mode: "debug"},
		Database: DatabaseConfig{DSN: "mysql://user@localhost/db"},
		Redis:    RedisConfig{DSN: "redis://localhost:6379"},
		JWT:      JWTConfig{Secret: "test-secret-key-min-32-chars!!"},
	}

	err := Validate(cfg)
	assert.Error(t, err)
	assert.Contains(t, err.Error(), "invalid database DSN")
}

func TestValidate_MissingRedisDSN(t *testing.T) {
	cfg := &Config{
		Server:   ServerConfig{Host: "localhost", Port: 8080, Mode: "debug"},
		Database: DatabaseConfig{DSN: "postgres://user@localhost:5432/db?sslmode=disable"},
		JWT:      JWTConfig{Secret: "test-secret-key-min-32-chars!!"},
	}

	err := Validate(cfg)
	assert.Error(t, err)
	assert.Contains(t, err.Error(), "redis DSN is required")
}

func TestValidate_InvalidRedisDSN(t *testing.T) {
	cfg := &Config{
		Server:   ServerConfig{Host: "localhost", Port: 8080, Mode: "debug"},
		Database: DatabaseConfig{DSN: "postgres://user@localhost:5432/db?sslmode=disable"},
		Redis:    RedisConfig{DSN: "not-a-valid-url://::"},
		JWT:      JWTConfig{Secret: "test-secret-key-min-32-chars!!"},
	}

	err := Validate(cfg)
	assert.Error(t, err)
	assert.Contains(t, err.Error(), "invalid redis DSN")
}

func TestValidate_JWTSecretInProduction(t *testing.T) {
	cfg := &Config{
		Server:   ServerConfig{Host: "localhost", Port: 8080, Mode: "release"},
		Database: DatabaseConfig{DSN: "postgres://user@localhost:5432/db?sslmode=disable"},
		Redis:    RedisConfig{DSN: "redis://localhost:6379"},
		JWT:      JWTConfig{Secret: "change-me-in-production"},
	}

	err := Validate(cfg)
	assert.Error(t, err)
	assert.Contains(t, err.Error(), "JWT secret must be changed in production")
}

func TestValidate_InvalidLogLevel(t *testing.T) {
	cfg := &Config{
		Server:   ServerConfig{Host: "localhost", Port: 8080, Mode: "debug"},
		Database: DatabaseConfig{DSN: "postgres://user@localhost:5432/db?sslmode=disable"},
		Redis:    RedisConfig{DSN: "redis://localhost:6379"},
		JWT:      JWTConfig{Secret: "test-secret-key-min-32-chars!!"},
		Log:      LogConfig{Level: "invalid"},
	}

	err := Validate(cfg)
	assert.Error(t, err)
	assert.Contains(t, err.Error(), "invalid log level")
}

func TestValidate_InvalidWorkerConcurrency(t *testing.T) {
	cfg := &Config{
		Server:   ServerConfig{Host: "localhost", Port: 8080, Mode: "debug"},
		Database: DatabaseConfig{DSN: "postgres://user@localhost:5432/db?sslmode=disable"},
		Redis:    RedisConfig{DSN: "redis://localhost:6379"},
		JWT:      JWTConfig{Secret: "test-secret-key-min-32-chars!!"},
		Log:      LogConfig{Level: "info"},
		Worker:   WorkerConfig{Concurrency: 0},
	}

	err := Validate(cfg)
	assert.Error(t, err)
	assert.Contains(t, err.Error(), "worker concurrency")
}

func TestValidate_SearchMeilisearchRequiresValidHost(t *testing.T) {
	cfg := &Config{
		Server:   ServerConfig{Host: "localhost", Port: 8080, Mode: "debug"},
		Database: DatabaseConfig{DSN: "postgres://user@localhost:5432/db?sslmode=disable"},
		Redis:    RedisConfig{DSN: "redis://localhost:6379"},
		JWT:      JWTConfig{Secret: "test-secret-key-min-32-chars!!"},
		Log:      LogConfig{Level: "info"},
		Worker:   WorkerConfig{Concurrency: 1, BlockTimeoutS: 5, SweepIntervalS: 30},
		Search:   SearchConfig{Engine: "meilisearch", Host: "not a url", TimeoutSeconds: 5},
	}

	err := Validate(cfg)
	assert.Error(t, err)
	assert.Contains(t, err.Error(), "invalid search.host")
}

func TestValidate_SearchDBFallbackAllowed(t *testing.T) {
	cfg := &Config{
		Server:   ServerConfig{Host: "localhost", Port: 8080, Mode: "debug"},
		Database: DatabaseConfig{DSN: "postgres://user@localhost:5432/db?sslmode=disable"},
		Redis:    RedisConfig{DSN: "redis://localhost:6379"},
		JWT:      JWTConfig{Secret: "test-secret-key-min-32-chars!!"},
		Log:      LogConfig{Level: "info"},
		Worker:   WorkerConfig{Concurrency: 1, BlockTimeoutS: 5, SweepIntervalS: 30},
		Search:   SearchConfig{Engine: "db"},
	}

	err := Validate(cfg)
	assert.NoError(t, err)
}

func TestValidate_SearchDBFallbackRejectedInRelease(t *testing.T) {
	cfg := &Config{
		Server:   ServerConfig{Host: "localhost", Port: 8080, Mode: "release"},
		Database: DatabaseConfig{DSN: "postgres://user@localhost:5432/db?sslmode=disable"},
		Redis:    RedisConfig{DSN: "redis://localhost:6379"},
		JWT:      JWTConfig{Secret: "test-secret-key-min-32-chars!!"},
		Log:      LogConfig{Level: "info"},
		Worker:   WorkerConfig{Concurrency: 1, BlockTimeoutS: 5, SweepIntervalS: 30},
		Search:   SearchConfig{Engine: "db"},
	}

	err := Validate(cfg)
	assert.Error(t, err)
	assert.Contains(t, err.Error(), "release mode requires meilisearch")
}

func TestDatabaseConfig_MigrateDSN(t *testing.T) {
	cfg := DatabaseConfig{
		DSN: "postgres://gochat:secret@localhost:5432/gochat_db?sslmode=disable",
	}

	dsn := cfg.MigrateDSN()
	assert.Equal(t, "postgres://gochat:secret@localhost:5432/gochat_db?sslmode=disable", dsn)
}

func TestJWTConfig_ExpiryDuration(t *testing.T) {
	cfg := JWTConfig{ExpiryHours: 24}
	dur := cfg.ExpiryDuration()
	assert.Equal(t, 24*time.Hour, dur)
}

func TestServerConfig_Address(t *testing.T) {
	cfg := ServerConfig{Host: "0.0.0.0", Port: 3000}
	addr := fmt.Sprintf("%s:%d", cfg.Host, cfg.Port)
	assert.Equal(t, "0.0.0.0:3000", addr)
}