ZDDC/zddc/internal/archive/resolver.go
2026-06-11 13:32:31 -05:00

98 lines
2.6 KiB
Go

package archive
import (
"strings"
)
// Resolve parses the .archive request filename and returns the server-relative
// path (no leading slash) of the resolved file within the named project. The
// caller serves that file in place — the .archive URL is intentionally stable
// across revisions so external links like .archive/<tracking>.html#section
// keep tracking the latest copy without exposing the per-transmittal URL.
//
// Project is the top-level segment of the .archive contextPath
// (/<project>/.../.archive/<filename>). An empty project — i.e. a request
// against /.archive/ at the very root — returns ("", false): stable refs
// must be project-rooted to avoid cross-project tracking-number collisions.
//
// Supported URL filename patterns (after stripping .html suffix):
// - trackingNumber → highest base revision of trackingNumber
// - trackingNumber_rev → base revision file for rev
// - trackingNumber_rev+C1 → modifier file (C1, B1, N1, Q1)
//
// Returns ("", false) if project is empty, the filename cannot be parsed, or
// no match exists in the project.
func Resolve(idx *Index, project, filename string) (string, bool) {
if project == "" {
return "", false
}
// Strip .html suffix
stem := strings.TrimSuffix(filename, ".html")
if stem == filename {
// No .html suffix — not a valid archive request
return "", false
}
idx.mu.RLock()
defer idx.mu.RUnlock()
pe, ok := idx.ByProject[project]
if !ok {
return "", false
}
// Try to split off revision part (last _ segment)
lastUnderscore := strings.LastIndex(stem, "_")
if lastUnderscore < 0 {
// No underscore — treat entire stem as tracking number
tracking := stem
te, ok := pe.ByTracking[tracking]
if !ok || te.HighestBaseRev == "" {
return "", false
}
re, ok := te.ByRevision[te.HighestBaseRev]
if !ok || re.BasePath == "" {
return "", false
}
return re.BasePath, true
}
tracking := stem[:lastUnderscore]
revPart := stem[lastUnderscore+1:]
// Split revPart on "+" to separate baseRev from modifier
plusIdx := strings.Index(revPart, "+")
var baseRev, modifier string
if plusIdx < 0 {
baseRev = revPart
modifier = ""
} else {
baseRev = revPart[:plusIdx]
modifier = revPart[plusIdx+1:]
}
te, ok := pe.ByTracking[tracking]
if !ok {
return "", false
}
re, ok := te.ByRevision[baseRev]
if !ok {
return "", false
}
if modifier == "" {
if re.BasePath == "" {
return "", false
}
return re.BasePath, true
}
// Modifier lookup
path, ok := re.Modifiers[modifier]
if !ok {
return "", false
}
return path, true
}