package main

import (
	"context"
	"fmt"
	"log"
	"net/url"
	"os"
	"path/filepath"

	"github.com/a-h/templ"
	"github.com/pelletier/go-toml/v2"
)

type Config struct {
	Title    string
	Domain   string
	Forge    string
	Menu     []*Link
	Packages []*Package
}

type Link struct {
	Name string
	URL  string
}

type Package struct {
	Name string
	URL  string
}

func must[T any](t T, err error) T {
	if err != nil {
		panic(err)
	}
	return t
}

func fatal(err error) {
	if err != nil {
		log.Fatal(err)
	}
}

func importString(config *Config, pkg Package) string {
	return fmt.Sprintf("%s git %s",
		must(url.JoinPath(config.Domain, pkg.Name)),
		must(url.JoinPath(config.Forge, pkg.Name)),
	)
}

func sourceString(config *Config, pkg Package) string {
	return fmt.Sprintf("%s _ %s %s",
		must(url.JoinPath(config.Domain, pkg.Name)),
		must(url.JoinPath(config.Forge, pkg.Name, "tree/main{/dir}")),
		must(url.JoinPath(config.Forge, pkg.Name, "tree/main{/dir}/{file}#n{line}")),
	)
}

func godocURL(config *Config, pkg *Package) string {
	return must(url.JoinPath("https://pkg.go.dev", packageImportPath(config, pkg)))
}

func packageImportPath(config *Config, pkg *Package) string {
	return must(url.JoinPath(config.Domain, pkg.Name))
}

func packageForgeURL(config *Config, pkg *Package) string {
	return must(url.JoinPath(config.Forge, pkg.Name))
}

func getConfig(filename string) (cfg *Config, err error) {
	cfg = new(Config)
	file, err := os.Open(filename)
	if err != nil {
		return nil, err
	}
	defer file.Close()
	dec := toml.NewDecoder(file)
	err = dec.Decode(cfg)
	if err != nil {
		return nil, err
	}

	return cfg, nil
}

const destDir = "dist"

func renderToFile(c templ.Component, filename string) error {
	pathname := filepath.Join(destDir, filename)
	err := os.MkdirAll(filepath.Dir(pathname), 0755)
	if err != nil {
		return err
	}
	file, err := os.Create(pathname)
	if err != nil {
		return err
	}
	defer file.Close()

	return c.Render(context.Background(), file)
}

func main() {
	cfg, err := getConfig("vanity.toml")
	fatal(err)

	err = renderToFile(
		ListPage(cfg),
		"index.html",
	)
	fatal(err)

	for _, pkg := range cfg.Packages {
		err = renderToFile(
			PackagePage(cfg, pkg),
			filepath.Join(pkg.Name, "index.html"),
		)
		fatal(err)
	}
}