// PicoClaw - Ultra-lightweight personal AI agent
// License: MIT
//
// Copyright (c) 2026 PicoClaw contributors

package providers

import (
	"fmt"

	"github.com/sipeed/picoclaw/pkg/config"
)

// CreateProvider creates a provider based on the configuration.
// It uses the model_list configuration (new format) to create providers.
// The old providers config is automatically converted to model_list during config loading.
// Returns the provider, the model ID to use, and any error.
func CreateProvider(cfg *config.Config) (LLMProvider, string, error) {
	model := cfg.Agents.Defaults.GetModelName()

	// Ensure model_list is populated from providers config if needed
	// This handles two cases:
	// 1. ModelList is empty - convert all providers
	// 2. ModelList has some entries but not all providers - merge missing ones
	if cfg.HasProvidersConfig() {
		providerModels := config.ConvertProvidersToModelList(cfg)
		existingModelNames := make(map[string]bool)
		for _, m := range cfg.ModelList {
			existingModelNames[m.ModelName] = true
		}
		for _, pm := range providerModels {
			if !existingModelNames[pm.ModelName] {
				cfg.ModelList = append(cfg.ModelList, pm)
			}
		}
	}

	// Must have model_list at this point
	if len(cfg.ModelList) == 0 {
		return nil, "", fmt.Errorf("no providers configured. Please add entries to model_list in your config")
	}

	// Get model config from model_list
	modelCfg, err := cfg.GetModelConfig(model)
	if err != nil {
		return nil, "", fmt.Errorf("model %q not found in model_list: %w", model, err)
	}

	// Inject global workspace if not set in model config
	if modelCfg.Workspace == "" {
		modelCfg.Workspace = cfg.WorkspacePath()
	}

	// Use factory to create provider
	provider, modelID, err := CreateProviderFromConfig(modelCfg)
	if err != nil {
		return nil, "", fmt.Errorf("failed to create provider for model %q: %w", model, err)
	}

	return provider, modelID, nil
}