package main

import (
	"strconv"
	"strings"
	"time"
)

type (
	// https://wiki.alpinelinux.org/wiki/Apk_spec
	Entry struct {
		Checksum         string     // C
		Version          string     // V
		Name             string     // P
		Architecture     *string    // A
		PackageSize      int        // S
		InstalledSize    int        // I
		Description      string     // T
		Url              string     // U
		License          string     // L
		Origin           *string    // o
		Maintainer       *string    // m
		BuildTime        *time.Time // t
		Commit           *string    // c
		ProviderPriority *int       // k
		Dependencies     []string   // D
		Provides         []string   // p
		InstallIf        []string   // i
	}
)

func (e *Entry) Properties() map[string]string {
	p := make(map[string]string)

	p["checksum"] = e.Checksum
	p["version"] = e.Version
	p["name"] = e.Name
	p["package size"] = strconv.Itoa(e.PackageSize)
	p["installed size"] = strconv.Itoa(e.InstalledSize)
	p["description"] = e.Description
	p["url"] = e.Url
	p["license"] = e.License

	if e.Architecture != nil {
		p["architecture"] = *e.Architecture
	}

	if e.Origin != nil {
		p["origin"] = *e.Origin
	}

	if e.Maintainer != nil {
		p["maintainer"] = *e.Maintainer
	}

	if e.BuildTime != nil {
		p["build time"] = e.BuildTime.String()
	}

	if e.Commit != nil {
		p["commit"] = *e.Commit
	}

	if e.ProviderPriority != nil {
		p["provider priority"] = strconv.Itoa(*e.ProviderPriority)
	}

	if len(e.Dependencies) > 0 {
		p["dependencies"] = strings.Join(e.Dependencies, " ")
	}

	if len(e.Provides) > 0 {
		p["provides"] = strings.Join(e.Provides, " ")
	}

	if len(e.InstallIf) > 0 {
		p["install if"] = strings.Join(e.InstallIf, " ")
	}

	return p
}

func ptr[T any](v T) *T {
	return &v
}

func split(line string) (string, string) {
	parts := strings.SplitN(line, ":", 2)
	return parts[0], parts[1]
}

func toInt(v string) int {
	i, _ := strconv.Atoi(v)
	return i
}

func Parse(lines []string) *Entry {
	entry := &Entry{}
	for _, line := range lines {
		r, c := split(line)
		switch r {
		case "C":
			entry.Checksum = c
		case "V":
			entry.Version = c
		case "P":
			entry.Name = c
		case "A":
			entry.Architecture = &c
		case "S":
			entry.PackageSize = toInt(c)
		case "I":
			entry.InstalledSize = toInt(c)
		case "T":
			entry.Description = c
		case "U":
			entry.Url = c
		case "L":
			entry.License = c
		case "o":
			entry.Origin = &c
		case "m":
			entry.Maintainer = &c
		case "t":
			entry.BuildTime = ptr(time.Unix(int64(toInt(c)), 0))
		case "c":
			entry.Commit = &c
		case "k":
			entry.ProviderPriority = ptr(toInt(c))
		case "D":
			entry.Dependencies = strings.Split(c, " ")
		case "p":
			entry.Dependencies = strings.Split(c, " ")
		case "i":
			entry.Dependencies = strings.Split(c, " ")
		}
	}
	return entry
}