package config

import (
	"fmt"
	"os"
	"time"

	"github.com/spf13/viper"
)

// Config holds the benchmark configuration.
type Config struct {
	APIEndpoint   string            `yaml:"apiEndpoint" mapstructure:"apiEndpoint"`
	APIKey        string            `yaml:"apiKey" mapstructure:"apiKey"` // Consider loading from env or secure store
	Model         string            `yaml:"model" mapstructure:"model"`
	Requests      int               `yaml:"requests"`
	Concurrency   int               `yaml:"concurrency"`
	RateLimit     int               `yaml:"rateLimit"` // Requests per second
	Duration      time.Duration     `yaml:"duration"`
	PromptTokens  int               `yaml:"promptTokens"`
	MaxTokens     int               `yaml:"maxTokens"`
	Streaming     bool              `yaml:"streaming" mapstructure:"streaming"`
	Timeout       time.Duration     `yaml:"timeout"`      // Request timeout
	RequestTimeout time.Duration    `yaml:"requestTimeout" mapstructure:"request_timeout"` // Timeout for individual HTTP requests (defaults to global Timeout if 0)
	OutputReport  string            `yaml:"outputReport"` // Path to save the HTML report
	Headers       map[string]string `yaml:"headers"`       // Custom HTTP headers
	Payload       map[string]any    `yaml:"payload"`       // Custom payload fields
	Client        string            `yaml:"client"`        // "fasthttp" or "nethttp"
	ReportFile    string            `yaml:"reportFile" mapstructure:"report_file"`    // Output file for the HTML report
	// Add other configuration parameters as needed
}

// LoadConfig loads configuration from the specified file path.
func LoadConfig(filePath string) (*Config, error) {
	// Check if the file exists
	if _, err := os.Stat(filePath); os.IsNotExist(err) {
		return nil, fmt.Errorf("config file not found at path: %s", filePath)
	}

	v := viper.New()
	v.SetConfigFile(filePath)
	v.SetConfigType("yaml")

	// Read the configuration file
	if err := v.ReadInConfig(); err != nil {
		return nil, fmt.Errorf("failed to read config file '%s': %w", filePath, err)
	}

	var config Config
	// Unmarshal the configuration into the Config struct
	if err := v.Unmarshal(&config); err != nil {
		return nil, fmt.Errorf("failed to unmarshal config from '%s': %w", filePath, err)
	}

	// Set default RequestTimeout if not provided
	if config.RequestTimeout <= 0 {
		config.RequestTimeout = config.Timeout
	}

	// TODO: Add validation for required fields if necessary
	return &config, nil
}