package server

import (
	"context"
	"os"
	"path/filepath"
	"slices"

	"jarl/internal/api"
	"jarl/internal/stats"
)

// storage reports the size of Jarl's databases and how full the disks
// Jarl uses are (the dashboard's Storage card).
func (s *Server) storage(ctx context.Context) *api.Storage {
	out := &api.Storage{Databases: []api.Database{}, Disks: []api.Disk{}}
	dbFile := func(label, path string) *api.Database {
		if path == "" || path == ":memory:" {
			return nil
		}
		d := api.Database{Label: label, Path: path}
		for _, suffix := range []string{"", "-wal", "-shm"} {
			if fi, err := os.Stat(path + suffix); err == nil {
				d.Bytes += fi.Size()
			}
		}
		out.Databases = append(out.Databases, d)
		out.Total += d.Bytes
		return &out.Databases[len(out.Databases)-1]
	}
	labels := []string{}
	dirs := map[string]string{}
	add := func(label, dir string) {
		if dir != "" {
			labels = append(labels, label)
			dirs[label] = dir
		}
	}
	const jarlDB, statsDB = "Jarl's database", "statistics database"
	if p := s.store.Path(); p != "" {
		dbFile(jarlDB, p)
		add(jarlDB, filepath.Dir(p))
	}
	if s.cfg.Stats != nil {
		if p := s.cfg.Stats.Store().Path(); p != "" && p != ":memory:" {
			if d := dbFile(statsDB, p); d != nil && s.cfg.Stats.Options().RetainQueries > 0 {
				if n, err := s.cfg.Stats.Store().QueryLogSize(ctx); err == nil {
					d.QueryLogRows = &n
				}
			}
			add(statsDB, filepath.Dir(p))
		}
		if lf := s.cfg.Stats.Options().LogFile; lf != "" {
			add("named's logs", filepath.Dir(lf))
		}
	}
	paths := s.eng.Config().Paths
	add("zone files", paths.ZoneDir)
	add("named.conf", paths.ConfigDir)
	add("Jarl's cache and blocklists", paths.CacheDir)
	add("backups", s.cfg.BackupDir)
	for _, d := range stats.DiskUsage(labels, dirs) {
		disk := api.Disk{Path: d.Path, Holds: d.Holds, Total: d.Total, Free: d.Free}
		for _, db := range out.Databases {
			if slices.Contains(d.Holds, db.Label) {
				disk.Databases += db.Bytes
			}
		}
		out.Disks = append(out.Disks, disk)
	}
	return out
}