package main

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

type Config struct {
	Links   []Link    `yaml:"links"`
	Monitor []Monitor `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 _, m := range cfg.Monitor {
		if seen[m.Name] {
			return nil, fmt.Errorf("duplicate name %q", m.Name)
		}
		seen[m.Name] = true
	}
	for _, it := range cfg.Exec {
		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.Percentages < 0 || it.Percentages > 8 {
			return nil, fmt.Errorf("monitor %q: percentages must be 1..8", 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
}