hmn/src/website/fishbowl.go

package website

import (
	"fmt"
	"html/template"
	"io"
	"io/fs"
	"net/http"
	"strings"
	"time"

	"git.handmade.network/hmn/hmn/src/hmnurl"
	"git.handmade.network/hmn/hmn/src/oops"
	"git.handmade.network/hmn/hmn/src/templates"
	"git.handmade.network/hmn/hmn/src/utils"
)

// This will skip the common path prefix for fishbowl files.
// We unfortunately need to do this because we want to use http.FileServer,
// but _that_ needs an http.FS, but _that_ needs an fs.FS...
var fishbowlFS = utils.Must1(fs.Sub(templates.FishbowlFS, "src/fishbowls"))
var fishbowlHTTPFS = http.StripPrefix("/fishbowl", http.FileServer(http.FS(fishbowlFS)))

type fishbowlInfo struct {
	Slug         string
	Title        string
	Month        time.Month
	Year         int
	ContentsPath string
}

var fishbowls = [...]fishbowlInfo{
	{
		Slug:  "internet-os",
		Title: "The future of operating systems in an Internet world",
		Month: time.May, Year: 2020,
	},
	{
		Slug:  "metaprogramming",
		Title: "Compile-time introspection and metaprogramming",
		Month: time.June, Year: 2020,
	},
	{
		Slug:  "lisp-jam",
		Title: "Lessons from the LISP Jam",
		Month: time.August, Year: 2020,
	},
	{
		Slug:  "parallel-programming",
		Title: "Approaches to parallel programming",
		Month: time.November, Year: 2020,
	},
	{
		Slug:  "skimming",
		Title: "Code skimmability as the root cause for bad code structure decisions", // real snappy, this one
		Month: time.January, Year: 2021,
	},
	{
		Slug:  "config",
		Title: "How to design to avoid configuration",
		Month: time.March, Year: 2021,
	},
	{
		Slug:  "simplicity-performance",
		Title: "The relationship of simplicity and performance",
		Month: time.May, Year: 2021,
	},
	{
		Slug:  "teaching-software",
		Title: "How software development is taught",
		Month: time.June, Year: 2021,
	},
	{
		Slug:  "flexible-software",
		Title: "How to design flexible software",
		Month: time.December, Year: 2021,
	},
	{
		Slug:  "oop",
		Title: "What, if anything, is OOP?",
		Month: time.May, Year: 2022,
		ContentsPath: "oop/OOP.html",
	},
}

func FishbowlIndex(c *RequestContext) ResponseData {
	type fishbowlTmpl struct {
		Date  string
		Title string
		Url   string
	}

	var fishbowlTmpls []fishbowlTmpl
	for _, f := range fishbowls {
		fishbowlTmpls = append(fishbowlTmpls, fishbowlTmpl{
			Date:  fmt.Sprintf("%s %d", f.Month.String(), f.Year),
			Title: f.Title,
			Url:   hmnurl.BuildFishbowl(f.Slug),
		})
	}

	var res ResponseData
	err := res.WriteTemplate("fishbowl_index.html", getBaseData(c, "Fishbowls", nil), c.Perf)
	if err != nil {
		return c.ErrorResponse(http.StatusInternalServerError, oops.New(err, "failed to render fishbowl index page"))
	}
	return res
}

func Fishbowl(c *RequestContext) ResponseData {
	slug := c.PathParams["slug"]
	var info fishbowlInfo

	// Only serve up valid fishbowls (with content)
	exists := false
	for _, fishbowl := range fishbowls {
		if fishbowl.Slug == slug && fishbowl.ContentsPath != "" {
			exists = true
			info = fishbowl
		}
	}
	if !exists {
		return FourOhFour(c)
	}

	// Ensure trailing slash (it matters for relative URLs in the HTML)
	if !strings.HasSuffix(c.URL().Path, "/") {
		return c.Redirect(c.URL().Path+"/", http.StatusFound)
	}

	type FishbowlData struct {
		templates.BaseData
		Slug     string
		Info     fishbowlInfo
		Contents template.HTML
	}

	contentsFile := utils.Must1(fishbowlFS.Open(info.ContentsPath))

	tmpl := FishbowlData{
		BaseData: getBaseData(c, info.Title, []templates.Breadcrumb{
			{Name: "Fishbowls", Url: hmnurl.BuildFishbowlIndex()},
			{Name: info.Title, Url: hmnurl.BuildFishbowl(slug)},
		}),
		Slug:     slug,
		Info:     info,
		Contents: template.HTML(utils.Must1(io.ReadAll(contentsFile))),
	}

	var res ResponseData
	err := res.WriteTemplate("fishbowl.html", tmpl, c.Perf)
	if err != nil {
		return c.ErrorResponse(http.StatusInternalServerError, oops.New(err, "failed to render fishbowl index page"))
	}
	return res
}

func FishbowlFiles(c *RequestContext) ResponseData {
	var res ResponseData
	fishbowlHTTPFS.ServeHTTP(&res, c.Req)
	AddCORSHeaders(c, &res)
	return res
}