package config

import (
	"fmt"
	"os"
	"time"

	"gopkg.in/yaml.v3"
)

// Config holds all configuration for the application
type Config struct {
	Server       ServerConfig       `yaml:"server"`
	Identity     IdentityConfig     `yaml:"identity"`
	Notification NotificationConfig `yaml:"notification"`
	Database     DatabaseConfig     `yaml:"database"`
	Rules        RulesConfig        `yaml:"rules"`
}

type ServerConfig struct {
	Port          int    `yaml:"port"`
	WebhookSecret string `yaml:"webhook_secret"`
}

type IdentityConfig struct {
	Provider string        `yaml:"provider"`
	CacheTTL time.Duration `yaml:"cache_ttl"`
	Gitea    GiteaConfig   `yaml:"gitea"`
}

type GiteaConfig struct {
	URL   string `yaml:"url"`
	Token string `yaml:"token"`
}

type NotificationConfig struct {
	Provider string      `yaml:"provider"`
	Slack    SlackConfig `yaml:"slack"`
}

type SlackConfig struct {
	BotToken       string `yaml:"bot_token"`
	DefaultChannel string `yaml:"default_channel"`
}

type DatabaseConfig struct {
	Driver string `yaml:"driver"`
	DSN    string `yaml:"dsn"`
}

type RulesConfig struct {
	PR      PRRules      `yaml:"pr"`
	Issue   IssueRules   `yaml:"issue"`
	Comment CommentRules `yaml:"comment"`
}

type PRRules struct {
	NotifyOwner     bool `yaml:"notify_owner"`
	NotifyReviewers bool `yaml:"notify_reviewers"`
	NotifyAssignees bool `yaml:"notify_assignees"`
}

type IssueRules struct {
	NotifyAssignees bool `yaml:"notify_assignees"`
}

type CommentRules struct {
	NotifyMentioned   bool `yaml:"notify_mentioned"`
	NotifyThreadOwner bool `yaml:"notify_thread_owner"`
	NotifyReviewers   bool `yaml:"notify_reviewers"`
}

// Load reads configuration from a YAML file
func Load(path string) (*Config, error) {
	data, err := os.ReadFile(path)
	if err != nil {
		return nil, fmt.Errorf("reading config file: %w", err)
	}

	// Expand environment variables
	data = []byte(os.ExpandEnv(string(data)))

	var cfg Config
	if err := yaml.Unmarshal(data, &cfg); err != nil {
		return nil, fmt.Errorf("parsing config file: %w", err)
	}

	// Set defaults
	if cfg.Server.Port == 0 {
		cfg.Server.Port = 8080
	}
	if cfg.Identity.CacheTTL == 0 {
		cfg.Identity.CacheTTL = 24 * time.Hour
	}
	if cfg.Database.Driver == "" {
		cfg.Database.Driver = "sqlite"
	}

	return &cfg, nil
}