patchwork

package engine

import (
	"context"

	"git.pablomurad.com/pablo/patchwork/internal/store"
)

// missingScansToRemove: a file must be absent from this many consecutive
// scans before its page leaves the feeds. One miss is often an upload that
// replaces the file by deleting it first.
const missingScansToRemove = 2

// Reconcile is called after a full scan with every path that exists. Pages
// whose file is absent move toward removal; present pages that were missing
// come back.
func (e *Engine) Reconcile(ctx context.Context, present map[string]bool, dryRun bool) ([]Result, error) {
	var out []Result
	err := e.Store.Tx(ctx, dryRun, func(q *store.Queries) error {
		pages, err := q.Pages(ctx, e.Source, true)
		if err != nil {
			return err
		}
		now := e.Now()
		for i := range pages {
			p := &pages[i]
			if present[p.Path] {
				if p.RemovedAt == nil && p.MissingScans == 0 {
					continue
				}
				restored := p.RemovedAt != nil
				p.RemovedAt, p.MissingScans = nil, 0
				if err := q.UpdatePage(ctx, p); err != nil {
					return err
				}
				if restored {
					out = append(out, Result{Path: p.Path, Slug: p.Slug, Action: Unchanged, Restored: true})
				}
				continue
			}
			if p.RemovedAt != nil {
				continue
			}
			p.MissingScans++
			if p.MissingScans >= missingScansToRemove {
				p.RemovedAt = &now
				out = append(out, Result{Path: p.Path, Slug: p.Slug, Action: Removed})
			}
			if err := q.UpdatePage(ctx, p); err != nil {
				return err
			}
		}
		return nil
	})
	return out, err
}

// ActivePages counts pages that haven't been removed.
func (e *Engine) ActivePages(ctx context.Context) (int, error) {
	pages, err := e.Store.Pages(ctx, e.Source, false)
	return len(pages), err
}