package main

import (
	"fmt"
	"gopkg.in/yaml.v3"
	"os"
)

type Config struct {
	Links   []Link `yaml:"links"`
	Monitor []Item `yaml:"monitor"`
	Exec    []Item `yaml:"exec"`
}

func loadConfig(path string) (*Config, error) {
	f, err := os.Open(path)
	if err != nil {
		return nil, err
	}
	defer f.Close()
	var cfg Config
	dec := yaml.NewDecoder(f)
	dec.KnownFields(true)
	if err := dec.Decode(&cfg); err != nil {
		return nil, fmt.Errorf("parse %s: %w", path, err)
	}
	seen := map[string]bool{} // item names are global keys (monVals, RunScript)
	for _, l := range cfg.Links {
		if seen[l.Name] {
			return nil, fmt.Errorf("duplicate name %q", l.Name)
		}
		seen[l.Name] = true
	}
	for _, list := range [][]Item{cfg.Monitor, cfg.Exec} {
		for _, it := range list {
			if seen[it.Name] {
				return nil, fmt.Errorf("duplicate name %q", it.Name)
			}
			seen[it.Name] = true
		}
	}
	for _, it := range cfg.Monitor {
		if it.Refresh <= 0 {
			return nil, fmt.Errorf("monitor %q: refresh must be > 0", it.Name)
		}
		if it.Data != "text" && it.Data != "percentage" {
			return nil, fmt.Errorf("monitor %q: data must be text|percentage", it.Name)
		}
	}
	for _, it := range cfg.Exec {
		if len(it.ArgTypes) != it.Args {
			return nil, fmt.Errorf("exec %q: arg_types must have args entries", it.Name)
		}
		for _, t := range it.ArgTypes {
			if t != "text" && t != "number" {
				return nil, fmt.Errorf("exec %q: arg type must be text|number", it.Name)
			}
		}
	}
	return &cfg, nil
}