package ceph

import (
	"io/fs"
	"log"

	"asciigoat.org/ini/basic"

	"darvaza.org/core"
)

var sectionMap = map[string]func(*Config, *basic.Section) error{
	"global": loadGlobalConfSection,
}

func loadConfSection(out *Config, src *basic.Section) error {
	h, ok := sectionMap[src.Key]
	if !ok {
		return core.Wrap(fs.ErrInvalid, "unknown section %q", src.Key)
	}

	return h(out, src)
}

func loadGlobalConfSection(out *Config, src *basic.Section) error {
	var cfg GlobalConfig

	for _, field := range src.Fields {
		if err := loadGlobalConfField(&cfg, field); err != nil {
			return core.Wrap(err, "global")
		}
	}

	out.Global = cfg
	return nil
}

func loadGlobalConfField(cfg *GlobalConfig, field basic.Field) error {
	log.Printf("%s[%q] = %q", "global", field.Key, field.Value)

	key, value := field.Key, field.Value

	switch key {
	case "fsid":
		return configFieldHandler(&cfg.FSID, key, value)
	case "mon_host":
		return configFieldHandler(&cfg.MonitorsAddr, key, value)
	case "mon_initial_members":
		return configFieldHandler(&cfg.Monitors, key, value)
	case "cluster_network":
		return configFieldHandler(&cfg.ClusterNetwork, key, value)
	default:
		return core.Wrap(fs.ErrNotExist, "field %q unknown", key)
	}
}

func configFieldHandler(vi any, key, value string) error

func newConfigFromDocument(doc *basic.Document) (*Config, error) {
	var out Config

	if len(doc.Global) > 0 {
		err := core.Wrap(fs.ErrInvalid, "fields before the first section")
		return nil, err
	}

	for i := range doc.Sections {
		src := &doc.Sections[i]
		if err := loadConfSection(&out, src); err != nil {
			return nil, err
		}
	}

	return &out, nil
}