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{
			Host:     "localhost",
			Port:     5432,
			User:     "gochat",
			Password: "secret",
			Name:     "gochat_db",
		},
		Redis: RedisConfig{
			URL: "redis://localhost:6379",
		},
		JWT: JWTConfig{
			Secret:             "test-secret-key-min-32-chars!!",
			ExpiryHours:        24,
			RefreshExpiryHours: 168,
		},
		Log:       LogConfig{Level: "info", Format: "json"},
		Captain:   CaptainConfig{Enabled: false},
		Worker:    WorkerConfig{Concurrency: 4},
		OAuth:     OAuthConfig{},
		RateLimit: RateLimitConfig{Enabled: true, RequestsPerMinute: 100, WindowSeconds: 60},
		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{Host: "localhost", Name: "db", User: "user"},
		Redis:    RedisConfig{URL: "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{Host: "localhost", Name: "db", User: "user"},
		Redis:    RedisConfig{URL: "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_MissingDBHost(t *testing.T) {
	cfg := &Config{
		Server:   ServerConfig{Host: "localhost", Port: 8080, Mode: "debug"},
		Database: DatabaseConfig{Name: "db", User: "user"},
		Redis:    RedisConfig{URL: "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 host is required")
}

func TestValidate_MissingDBName(t *testing.T) {
	cfg := &Config{
		Server:   ServerConfig{Host: "localhost", Port: 8080, Mode: "debug"},
		Database: DatabaseConfig{Host: "localhost", User: "user"},
		Redis:    RedisConfig{URL: "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 name is required")
}

func TestValidate_MissingRedisURL(t *testing.T) {
	cfg := &Config{
		Server:   ServerConfig{Host: "localhost", Port: 8080, Mode: "debug"},
		Database: DatabaseConfig{Host: "localhost", Name: "db", User: "user"},
		JWT:      JWTConfig{Secret: "test-secret-key-min-32-chars!!"},
	}

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

func TestValidate_InvalidRedisURL(t *testing.T) {
	cfg := &Config{
		Server:   ServerConfig{Host: "localhost", Port: 8080, Mode: "debug"},
		Database: DatabaseConfig{Host: "localhost", Name: "db", User: "user"},
		Redis:    RedisConfig{URL: "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 URL")
}

func TestValidate_JWTSecretInProduction(t *testing.T) {
	cfg := &Config{
		Server:   ServerConfig{Host: "localhost", Port: 8080, Mode: "release"},
		Database: DatabaseConfig{Host: "localhost", Name: "db", User: "user"},
		Redis:    RedisConfig{URL: "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{Host: "localhost", Name: "db", User: "user"},
		Redis:    RedisConfig{URL: "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{Host: "localhost", Name: "db", User: "user"},
		Redis:    RedisConfig{URL: "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{Host: "localhost", Name: "db", User: "user"},
		Redis:     RedisConfig{URL: "redis://localhost:6379"},
		JWT:       JWTConfig{Secret: "test-secret-key-min-32-chars!!"},
		Log:       LogConfig{Level: "info"},
		Worker:    WorkerConfig{Concurrency: 1},
		RateLimit: RateLimitConfig{RequestsPerMinute: 100, WindowSeconds: 60},
		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{Host: "localhost", Name: "db", User: "user"},
		Redis:     RedisConfig{URL: "redis://localhost:6379"},
		JWT:       JWTConfig{Secret: "test-secret-key-min-32-chars!!"},
		Log:       LogConfig{Level: "info"},
		Worker:    WorkerConfig{Concurrency: 1},
		RateLimit: RateLimitConfig{RequestsPerMinute: 100, WindowSeconds: 60},
		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{Host: "localhost", Name: "db", User: "user"},
		Redis:     RedisConfig{URL: "redis://localhost:6379"},
		JWT:       JWTConfig{Secret: "test-secret-key-min-32-chars!!"},
		Log:       LogConfig{Level: "info"},
		Worker:    WorkerConfig{Concurrency: 1},
		RateLimit: RateLimitConfig{RequestsPerMinute: 100, WindowSeconds: 60},
		Search:    SearchConfig{Engine: "db"},
	}

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

func TestDatabaseConfig_DSN(t *testing.T) {
	cfg := DatabaseConfig{
		Host:     "localhost",
		Port:     5432,
		User:     "gochat",
		Password: "secret",
		DBName:   "gochat_db",
		SSLMode:  "disable",
	}

	dsn := cfg.DSN()
	assert.Contains(t, dsn, "host=localhost")
	assert.Contains(t, dsn, "port=5432")
	assert.Contains(t, dsn, "user=gochat")
	assert.Contains(t, dsn, "dbname=gochat_db")
	assert.Contains(t, dsn, "sslmode=disable")
}

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)
}