package config

import (
	"context"
	"fmt"
)

// ProviderConfig holds provider-specific settings.
type ProviderConfig struct {
	Type        string  `yaml:"type"`
	Model       string  `yaml:"model"`
	APIKey      string  `yaml:"api_key"`
	BaseURL     string  `yaml:"base_url,omitempty"`
	MaxTokens   int     `yaml:"max_tokens,omitempty"`
	Temperature float32 `yaml:"temperature,omitempty"`
}

// ToolPolicy controls which tools are available and their permissions.
type ToolPolicy struct {
	DefaultPermission string   `yaml:"default_permission"`
	AllowList         []string `yaml:"allow_list,omitempty"`
	DenyList          []string `yaml:"deny_list,omitempty"`
}

// LoggingConfig controls logging output.
type LoggingConfig struct {
	Level  string `yaml:"level"`
	Format string `yaml:"format"`
	Output string `yaml:"output"`
}

// Config is the top-level configuration for the agent.
type Config struct {
	Model    string         `yaml:"model"`
	Provider ProviderConfig `yaml:"provider"`
	Tools    ToolPolicy     `yaml:"tools"`
	Logging  LoggingConfig  `yaml:"logging"`
}

// Loader is responsible for loading configuration from various sources.
type Loader interface {
	Load(ctx context.Context, workdir string) (Config, error)
}

// ErrConfigNotFound is returned when no configuration file is found.
var ErrConfigNotFound = fmt.Errorf("config file not found")

// ErrInvalidConfig is returned when the configuration is invalid.
var ErrInvalidConfig = fmt.Errorf("invalid configuration")

// LoadDefault returns a Config with sensible defaults.
func LoadDefault() Config {
	return Config{
		Model: "gpt-4o",
		Provider: ProviderConfig{
			Type:        "openai",
			Model:       "gpt-4o",
			Temperature: 0.7,
			MaxTokens:   4096,
		},
		Tools: ToolPolicy{
			DefaultPermission: "allow",
		},
		Logging: LoggingConfig{
			Level:  "info",
			Format: "text",
			Output: "stderr",
		},
	}
}