// Package meta defines properties about this project.
package meta

import (
	"fmt"
	"path"
	"time"
)

// VersionTagPrefix is the prefix used on Git tags corresponding to semantic
// version releases.
const VersionTagPrefix = "v"

// Properties about this software package.
type Properties struct {
	// Name is the project name.
	Name string

	// FullName is the "owner/name" identifier for the project.
	FullName string

	// Description is the concise project headline.
	Description string

	// BuildVersion is the version that was built. Typically populated at build
	// time and will typically be empty for non-release builds.
	BuildVersion string

	// ReleaseVersion is the version of the most recent release.
	ReleaseVersion string

	// ReleaseDate is the date of the most recent release. (RFC3339 date format.)
	ReleaseDate string

	// ConceptDOI is the DOI for all versions.
	ConceptDOI string

	// DOI for the most recent release.
	DOI string

	// ZenodoID is the Zenodo deposit ID for the most recent release.
	ZenodoID string
}

// Meta defines specific properties for the current version of this software.
var Meta = &Properties{
	Name:           "addchain",
	FullName:       "mmcloughlin/addchain",
	Description:    "Cryptographic Addition Chain Generation in Go",
	BuildVersion:   buildversion,
	ReleaseVersion: releaseversion,
	ReleaseDate:    releasedate,
	ConceptDOI:     conceptdoi,
	DOI:            doi,
	ZenodoID:       zenodoid,
}

// Title is a full project title, suitable for a citation.
func (p *Properties) Title() string {
	return fmt.Sprintf("%s: %s", p.Name, p.Description)
}

// IsRelease reports whether the built version is a release.
func (p *Properties) IsRelease() bool {
	return p.BuildVersion == p.ReleaseVersion
}

// ReleaseTag returns the release tag corresponding to the most recent release.
func (p *Properties) ReleaseTag() string {
	return VersionTagPrefix + p.ReleaseVersion
}

// Module returns the Go module path.
func (p *Properties) Module() string {
	return path.Join("github.com", p.FullName)
}

// RepositoryURL returns a URL to the hosted repository.
func (p *Properties) RepositoryURL() string {
	return "https://" + p.Module()
}

// ReleaseURL returns the URL to the release page.
func (p *Properties) ReleaseURL() string {
	return fmt.Sprintf("%s/releases/tag/%s", p.RepositoryURL(), p.ReleaseTag())
}

// ReleaseTime returns the release date as a time object.
func (p *Properties) ReleaseTime() (time.Time, error) {
	return time.Parse("2006-01-02", p.ReleaseDate)
}

// DOIURL returns the DOI URL corresponding to the most recent release.
func (p *Properties) DOIURL() string { return doiurl(p.DOI) }

// ConceptDOIURL returns the DOI URL corresponding to the most recent release.
func (p *Properties) ConceptDOIURL() string { return doiurl(p.ConceptDOI) }

func doiurl(doi string) string {
	return "https://doi.org/" + doi
}