package config

import (
	"fmt"
	"os"
	"time"

	"gopkg.in/yaml.v3"
)

type Config struct {
	ServerName        string        `yaml:"server_name"`
	DiscordWebhookURL string        `yaml:"discord_webhook_url"`
	NotifyRoleID      string        `yaml:"notify_role_id"`
	SampleInterval    time.Duration `yaml:"sample_interval"`
	SummaryInterval   time.Duration `yaml:"summary_interval"`
	RequestTimeout    time.Duration `yaml:"request_timeout"`
	Thresholds        Thresholds    `yaml:"thresholds"`
	Sites             []Site        `yaml:"sites"`
}

type Thresholds struct {
	DiskUsedPercentWarning  float64 `yaml:"disk_used_percent_warning"`
	DiskUsedPercentCritical float64 `yaml:"disk_used_percent_critical"`
	FreeGBWarning           float64 `yaml:"free_gb_warning"`
	FreeGBCritical          float64 `yaml:"free_gb_critical"`
	InodeUsedPercentWarning float64 `yaml:"inode_used_percent_warning"`
	InodeUsedPercentCritical float64 `yaml:"inode_used_percent_critical"`
	MemoryUsedPercentWarning float64 `yaml:"memory_used_percent_warning"`
	MemoryUsedPercentCritical float64 `yaml:"memory_used_percent_critical"`
	SwapUsedPercentWarning   float64 `yaml:"swap_used_percent_warning"`
	SwapUsedPercentCritical  float64 `yaml:"swap_used_percent_critical"`
	CPUAvg15mWarning        float64 `yaml:"cpu_avg_15m_warning"`
	CPUAvg15mCritical       float64 `yaml:"cpu_avg_15m_critical"`
	CPUAvg12hWarning        float64 `yaml:"cpu_avg_12h_warning"`
	CPUAvg12hCritical       float64 `yaml:"cpu_avg_12h_critical"`
	LoadPerCoreWarning      float64 `yaml:"load_per_core_warning"`
	LoadPerCoreCritical     float64 `yaml:"load_per_core_critical"`
	ProcessCountWarning     int     `yaml:"process_count_warning"`
	ProcessCountCritical    int     `yaml:"process_count_critical"`
}

type Site struct {
	Name           string        `yaml:"name"`
	URL            string        `yaml:"url"`
	ExpectedStatus int           `yaml:"expected_status"`
	Timeout        time.Duration `yaml:"timeout"`
}

func Load(path string) (Config, error) {
	data, err := os.ReadFile(path)
	if err != nil {
		return Config{}, err
	}

	var cfg Config
	if err := yaml.Unmarshal(data, &cfg); err != nil {
		return Config{}, err
	}

	applyDefaults(&cfg)
	if err := cfg.Validate(); err != nil {
		return Config{}, err
	}

	return cfg, nil
}

func applyDefaults(cfg *Config) {
	if cfg.SampleInterval == 0 {
		cfg.SampleInterval = time.Minute
	}
	if cfg.SummaryInterval == 0 {
		cfg.SummaryInterval = 6 * time.Hour
	}
	if cfg.RequestTimeout == 0 {
		cfg.RequestTimeout = 10 * time.Second
	}
	for index := range cfg.Sites {
		if cfg.Sites[index].ExpectedStatus == 0 {
			cfg.Sites[index].ExpectedStatus = 200
		}
		if cfg.Sites[index].Timeout == 0 {
			cfg.Sites[index].Timeout = cfg.RequestTimeout
		}
	}
	if cfg.Thresholds.ProcessCountWarning == 0 {
		cfg.Thresholds.ProcessCountWarning = 350
	}
	if cfg.Thresholds.ProcessCountCritical == 0 {
		cfg.Thresholds.ProcessCountCritical = 500
	}
}

func (cfg Config) Validate() error {
	if cfg.ServerName == "" {
		return fmt.Errorf("server_name is required")
	}
	if cfg.DiscordWebhookURL == "" {
		return fmt.Errorf("discord_webhook_url is required")
	}
	if cfg.SampleInterval <= 0 {
		return fmt.Errorf("sample_interval must be > 0")
	}
	if cfg.SummaryInterval <= 0 {
		return fmt.Errorf("summary_interval must be > 0")
	}
	for _, site := range cfg.Sites {
		if site.Name == "" {
			return fmt.Errorf("site name is required")
		}
		if site.URL == "" {
			return fmt.Errorf("site URL is required for %s", site.Name)
		}
	}
	return nil
}