package config

import (
	"log"
	"os"
	"strconv"
	"strings"

	"github.com/joho/godotenv"
)

// Config holds all runtime configuration for the GoClaw Gateway.
//
// LLM Provider selection (via LLM_BASE_URL env):
//
//	Cloud (default):  https://ollama.com/v1          — Ollama Cloud API (requires OLLAMA_API_KEY)
//	OpenAI-compat:    https://api.openai.com/v1       — OpenAI or any OpenAI-compatible endpoint
//	Local GPU node:   http://localhost:11434/v1        — Local Ollama (only on machines with GPU)
//
// To use a local Ollama instance on a GPU-equipped agent node, set:
//
//	LLM_BASE_URL=http://<gpu-node-ip>:11434/v1
//	LLM_API_KEY=                                      # (empty for local Ollama)
type Config struct {
	// Server
	Port string

	// LLM / Ollama Cloud
	// LLM_BASE_URL — OpenAI-compatible base URL (without trailing slash, /v1 suffix included).
	// Default: https://ollama.com/v1 (Ollama Cloud).
	// For local GPU agents set LLM_BASE_URL=http://<host>:11434/v1
	LLMBaseURL string
	LLMAPIKey  string

	// Deprecated aliases kept for backward-compat (mapped to LLMBaseURL / LLMAPIKey)
	OllamaBaseURL string
	OllamaAPIKey  string

	// Database (MySQL/TiDB)
	DatabaseURL string

	// Project root (for file tools)
	ProjectRoot string

	// Gateway defaults
	DefaultModel       string
	MaxToolIterations  int
	RequestTimeoutSecs int
}

func Load() *Config {
	// Try to load .env from parent directory (project root) or current dir
	_ = godotenv.Load("../.env")
	_ = godotenv.Load(".env")

	maxIter, _ := strconv.Atoi(getEnv("GATEWAY_MAX_TOOL_ITERATIONS", "10"))
	timeout, _ := strconv.Atoi(getEnv("GATEWAY_REQUEST_TIMEOUT_SECS", "120"))

	// Resolve LLM base URL — priority: LLM_BASE_URL > OLLAMA_BASE_URL > default cloud
	rawLLMURL := getEnvFirst(
		"LLM_BASE_URL",      // preferred new name
		"OLLAMA_BASE_URL",   // legacy alias
	)
	if rawLLMURL == "" {
		// Default: Ollama Cloud (OpenAI-compatible, requires OLLAMA_API_KEY)
		rawLLMURL = "https://ollama.com/v1"
	}
	// Normalise: strip trailing slash, ensure /v1 suffix for bare Ollama hosts
	llmBaseURL := normaliseLLMURL(rawLLMURL)

	// Resolve API key — priority: LLM_API_KEY > OLLAMA_API_KEY
	llmAPIKey := getEnvFirst("LLM_API_KEY", "OLLAMA_API_KEY")

	cfg := &Config{
		Port:               getEnv("GATEWAY_PORT", "18789"),
		LLMBaseURL:         llmBaseURL,
		LLMAPIKey:          llmAPIKey,
		OllamaBaseURL:      llmBaseURL, // backward-compat alias
		OllamaAPIKey:       llmAPIKey,  // backward-compat alias
		DatabaseURL:        getEnv("DATABASE_URL", ""),
		ProjectRoot:        getEnv("PROJECT_ROOT", "/home/ubuntu/goclaw-control-center"),
		DefaultModel:       getEnv("DEFAULT_MODEL", "qwen2.5:7b"),
		MaxToolIterations:  maxIter,
		RequestTimeoutSecs: timeout,
	}

	if cfg.LLMAPIKey == "" {
		log.Println("[Config] WARNING: LLM_API_KEY / OLLAMA_API_KEY is not set — cloud API calls will fail")
	}
	if cfg.DatabaseURL == "" {
		log.Println("[Config] WARNING: DATABASE_URL is not set — agent config will use defaults")
	}

	log.Printf("[Config] LLM endpoint: %s", cfg.LLMBaseURL)

	return cfg
}

// normaliseLLMURL ensures the URL has a /v1 suffix for bare Ollama hosts.
// Examples:
//
//	"http://localhost:11434"   → "http://localhost:11434/v1"
//	"http://localhost:11434/"  → "http://localhost:11434/v1"
//	"https://ollama.com/v1"   → "https://ollama.com/v1"   (unchanged)
//	"https://api.openai.com/v1" → unchanged
func normaliseLLMURL(raw string) string {
	u := strings.TrimRight(raw, "/")
	if !strings.HasSuffix(u, "/v1") {
		u += "/v1"
	}
	return u
}

// getEnvFirst returns the value of the first non-empty env variable from the list.
func getEnvFirst(keys ...string) string {
	for _, k := range keys {
		if v := os.Getenv(k); v != "" {
			return v
		}
	}
	return ""
}

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