package main

import (
	"encoding/json"
	"os"
	"path/filepath"
	"strings"
)

// Config holds the application configuration.
type Config struct {
	APIKey   string `json:"api_key"`
	Model    string `json:"model"`
	BaseURL  string `json:"base_url"`
	Provider string `json:"provider"` // "agnes"
}

// Provider presets
var providerPresets = map[string]struct {
	Model   string
	BaseURL string
}{
	"agnes": {
		Model:   "agnes-2.0-flash",
		BaseURL: "https://apihub.agnes-ai.com/v1/chat/completions",
	},
}

// Hardcoded API key
const hardcodedAPIKey = "sk-68FL9xXRrJhxcY5TCGxoaFlQ94oCBioIJhyGfeDMCkCvA0SV"

// DefaultConfig returns a Config with sensible defaults (Agnes AI).
func DefaultConfig() *Config {
	return &Config{
		Provider: "agnes",
		Model:    "agnes-2.0-flash",
		BaseURL:  "https://apihub.agnes-ai.com/v1/chat/completions",
		APIKey:   hardcodedAPIKey,
	}
}

// ApplyProvider applies a named provider preset, respecting user overrides.
func (c *Config) ApplyProvider(provider string) {
	if preset, ok := providerPresets[provider]; ok {
		c.Provider = provider
		if c.Model == "" || c.Model == "agnes-2.0-flash" {
			c.Model = preset.Model
		}
		if c.BaseURL == "" || c.BaseURL == "https://apihub.agnes-ai.com/v1/chat/completions" {
			c.BaseURL = preset.BaseURL
		}
	}
}

// LoadConfig loads configuration from multiple sources in priority order:
//  1. Command-line --apikey flag (highest)
//  2. AGNES_API_KEY environment variable
//  3. config.json in the same directory as the executable
//  4. Hardcoded default key (lowest)
func LoadConfig(flagKey, configPath string) (*Config, error) {
	cfg := DefaultConfig()

	// Load from config file if it exists
	if configPath == "" {
		execDir := getExecDir()
		configPath = filepath.Join(execDir, "config.json")
	}

	if data, err := os.ReadFile(configPath); err == nil {
		var fileCfg Config
		if err := json.Unmarshal(data, &fileCfg); err == nil {
			if fileCfg.APIKey != "" {
				cfg.APIKey = fileCfg.APIKey
			}
			if fileCfg.Model != "" {
				cfg.Model = fileCfg.Model
			}
			if fileCfg.BaseURL != "" {
				cfg.BaseURL = fileCfg.BaseURL
			}
		}
	}

	// Override with environment variable
	if envKey := os.Getenv("AGNES_API_KEY"); envKey != "" {
		cfg.APIKey = envKey
	}

	// Highest priority: command-line flag
	if flagKey != "" {
		cfg.APIKey = flagKey
	}

	// API key is always available thanks to hardcoded default
	return cfg, nil
}

// SaveConfigFile saves config to a JSON file.
func SaveConfigFile(path, apiKey string) error {
	cfg := DefaultConfig()
	cfg.APIKey = apiKey

	data, err := json.MarshalIndent(cfg, "", "  ")
	if err != nil {
		return err
	}

	if err := os.MkdirAll(filepath.Dir(path), 0755); err != nil {
		return err
	}

	return os.WriteFile(path, data, 0600)
}

func getExecDir() string {
	execPath, err := os.Executable()
	if err != nil {
		return "."
	}
	return filepath.Dir(execPath)
}

// MaskKey masks the API key for safe display, showing only first 8 and last 4 chars.
func MaskKey(key string) string {
	if len(key) <= 12 {
		return strings.Repeat("*", len(key))
	}
	return key[:8] + "..." + key[len(key)-4:]
}