package handlers

import (
	"errors"
	"io/fs"
	"path/filepath"
	"time"

	"github.com/dustin/go-humanize"
	"sneak.berlin/go/webhooker/internal/database"
	"sneak.berlin/go/webhooker/internal/delivery"
)

// TargetRowView is one row of the target list on a webhook's page.
type TargetRowView struct {
	delivery.TargetView

	// Archive is a database target's archive file, and nil for a target
	// of any other type.
	Archive *ArchiveFileView
}

// ArchiveFileView is what a database target's row shows about its
// archive file.
type ArchiveFileView struct {
	Name string

	// Note stands in for the size and the last write when there are
	// none to show, and is empty when there are.
	Note string

	// Size is the size on disk. Written is how long ago the file was
	// last written, and WrittenUTC the full time the page shows on
	// hover.
	Size       string
	Written    string
	WrittenUTC string
}

// targetRows projects a webhook's targets for the target list on its
// page.
func (h *Handlers) targetRows(
	webhook *database.Webhook, targets []database.Target,
) []TargetRowView {
	views := delivery.NewTargetViews(targets)
	rows := make([]TargetRowView, len(views))

	// NewTargetViews returns one view per target, in order.
	for i := range views {
		rows[i].TargetView = views[i]

		if targets[i].Type == database.TargetTypeDatabase {
			rows[i].Archive = h.archiveFileView(webhook, &targets[i])
		}
	}

	return rows
}

// archiveFileView describes a database target's archive file from the
// file's metadata alone; the archive is never opened. The file is found
// by the name the archive writer uses, so it follows a rename of the
// webhook or the target.
func (h *Handlers) archiveFileView(
	webhook *database.Webhook, target *database.Target,
) *ArchiveFileView {
	path := delivery.ArchivePath(h.dbMgr, webhook, target)
	view := &ArchiveFileView{Name: filepath.Base(path)}

	file, err := delivery.StatArchive(path)

	switch {
	case errors.Is(err, fs.ErrNotExist):
		view.Note = "not created yet"
	case err != nil:
		h.log.Error(
			"failed to read archive file metadata",
			"target_id", target.ID,
			"error", err,
		)

		view.Note = "could not be read"
	default:
		view.Size = humanize.Bytes(uint64(file.Size)) //nolint:gosec // never negative
		view.Written = humanize.Time(file.Written)
		view.WrittenUTC = file.Written.UTC().Format(time.DateTime) + " UTC"
	}

	return view
}