feat: like button (only inmem-cache for now)

3 files changed, 183 insertions, 17 deletions

diff --git a/internal/router/api-v1-like.go b/internal/router/api-v1-like.go
new file mode 100644
index 0000000..1732c77
--- /dev/null
+++ b/internal/router/api-v1-like.go
@@ -0,0 +1,117 @@
+package router
+
+import (
+	"fmt"
+	"log/slog"
+	"net/url"
+	"strconv"
+	"strings"
+
+	"github.com/SayaAndy/saya-today-web/internal/b2"
+	"github.com/gofiber/fiber/v2"
+)
+
+func init() {
+	tm.Add("blog-page-like-button", "views/partials/blog-page-like-button.html")
+}
+
+func Api_V1_Like_Put(b2 *b2.B2Client) func(c *fiber.Ctx) error {
+	return func(c *fiber.Ctx) error {
+		c.Set(fiber.HeaderContentType, fiber.MIMETextPlainCharsetUTF8)
+
+		referer := c.Get("Referer", "")
+		if referer == "" {
+			return c.Status(fiber.ErrBadRequest.Code).SendString("'Referer' header is empty")
+		}
+		urlStruct, err := url.ParseRequestURI(referer)
+		if err != nil {
+			return c.Status(fiber.ErrBadRequest.Code).SendString(fmt.Sprintf("'Referer' header is invalid: %s", err.Error()))
+		}
+
+		path := urlStruct.EscapedPath()
+		pathParts := strings.Split(strings.Trim(path, "/"), "/")
+		if len(pathParts) != 3 {
+			return c.Status(fiber.ErrBadRequest.Code).SendString("'Referer' header is invalid: expect format '/{lang}/blog/{page}'")
+		}
+
+		lang, page := pathParts[0], pathParts[2]
+
+		pageLink := lang + "/" + page + ".md"
+		if pages, _ := b2.Scan(pageLink); len(pages) == 0 {
+			return c.Status(fiber.ErrNotFound.Code).SendString(fmt.Sprintf("server did not find '%s' article", pageLink))
+		}
+
+		ip := c.IP()
+		newLikeStatus, err := strconv.ParseBool(c.FormValue("like", "true"))
+		if err != nil {
+			return c.Status(fiber.ErrBadRequest.Code).SendString("invalid 'like' value")
+		}
+
+		if newLikeStatus {
+			CCache.LikeOn(ip, page)
+		} else {
+			CCache.LikeOff(ip, page)
+		}
+
+		slog.Debug("someone pressed the like button!", slog.String("ip", ip), slog.String("page", page), slog.String("new_like_status", fmt.Sprint(newLikeStatus)))
+		if c.Get("HX-Request", "false") == "true" {
+			content, err := tm.Render("blog-page-like-button", fiber.Map{
+				"Liked": newLikeStatus,
+			})
+			if err != nil {
+				slog.Warn("failed to generate div", slog.String("path", path), slog.String("error", err.Error()))
+				return c.Status(fiber.ErrInternalServerError.Code).SendString("failed to generate div")
+			}
+			c.Set(fiber.HeaderContentType, fiber.MIMETextHTMLCharsetUTF8)
+			return c.Status(fiber.StatusOK).Send(content)
+		}
+
+		return c.Status(fiber.StatusOK).SendString(fmt.Sprint(newLikeStatus))
+	}
+}
+
+func Api_V1_Like_Get(b2 *b2.B2Client) func(c *fiber.Ctx) error {
+	return func(c *fiber.Ctx) error {
+		c.Set(fiber.HeaderContentType, fiber.MIMETextPlainCharsetUTF8)
+
+		referer := c.Get("Referer", "")
+		if referer == "" {
+			return c.Status(fiber.ErrBadRequest.Code).SendString("'Referer' header is empty")
+		}
+		urlStruct, err := url.ParseRequestURI(referer)
+		if err != nil {
+			return c.Status(fiber.ErrBadRequest.Code).SendString(fmt.Sprintf("'Referer' header is invalid: %s", err.Error()))
+		}
+
+		path := urlStruct.EscapedPath()
+		pathParts := strings.Split(strings.Trim(path, "/"), "/")
+		if len(pathParts) != 3 {
+			return c.Status(fiber.ErrBadRequest.Code).SendString("'Referer' header is invalid: expect format '/{lang}/blog/{page}'")
+		}
+
+		lang, page := pathParts[0], pathParts[2]
+
+		pageLink := lang + "/" + page + ".md"
+		if pages, _ := b2.Scan(pageLink); len(pages) == 0 {
+			return c.Status(fiber.ErrNotFound.Code).SendString(fmt.Sprintf("server did not find '%s' article", pageLink))
+		}
+
+		ip := c.IP()
+		likeStatus := CCache.GetLikeStatus(ip, page)
+
+		slog.Debug("someone requested the like status!", slog.String("ip", ip), slog.String("page", page), slog.Bool("like_status", likeStatus))
+		if c.Get("HX-Request", "false") == "true" {
+			content, err := tm.Render("blog-page-like-button", fiber.Map{
+				"Liked": likeStatus,
+			})
+			if err != nil {
+				slog.Warn("failed to generate div", slog.String("path", path), slog.String("error", err.Error()))
+				return c.Status(fiber.ErrInternalServerError.Code).SendString("failed to generate div")
+			}
+			c.Set(fiber.HeaderContentType, fiber.MIMETextHTMLCharsetUTF8)
+			return c.Status(fiber.StatusOK).Send(content)
+		}
+
+		return c.Status(fiber.StatusOK).SendString(fmt.Sprint(likeStatus))
+	}
+}
diff --git a/internal/router/client-cache.go b/internal/router/client-cache.go
index a4a0cc2..3104a66 100644
--- a/internal/router/client-cache.go
+++ b/internal/router/client-cache.go
@@ -9,40 +9,90 @@ import (
 )
 
 type ClientCache struct {
-	hashMap  map[string][]byte
-	mutexMap map[string]*sync.Mutex
-	salt     []byte
+	hashMap      map[string]string
+	mutexLikeMap map[string]*sync.Mutex
+	mutexHashMap map[string]*sync.Mutex
+	likePageMap  map[string]map[string]struct{}
+	salt         []byte
 }
 
 var CCache *ClientCache
 
 func NewClientCache(salt []byte) *ClientCache {
 	return &ClientCache{
-		hashMap:  make(map[string][]byte),
-		mutexMap: make(map[string]*sync.Mutex),
-		salt:     salt,
+		hashMap:      make(map[string]string),
+		mutexLikeMap: make(map[string]*sync.Mutex),
+		mutexHashMap: make(map[string]*sync.Mutex),
+		likePageMap:  make(map[string]map[string]struct{}),
+		salt:         salt,
 	}
 }
 
-func (c *ClientCache) GetHash(id string) []byte {
-
+func (c *ClientCache) GetHash(id string) string {
 	if val, ok := c.hashMap[id]; ok {
-		slog.Debug("gave an old hash", slog.String("hash", base64.RawStdEncoding.EncodeToString(val)))
+		slog.Debug("gave an old hash", slog.String("hash", val))
 		return val
 	}
 
-	if _, ok := c.mutexMap[id]; !ok {
-		c.mutexMap[id] = &sync.Mutex{}
+	if _, ok := c.mutexHashMap[id]; !ok {
+		c.mutexHashMap[id] = &sync.Mutex{}
 	}
-	c.mutexMap[id].Lock()
-	defer c.mutexMap[id].Unlock()
+	c.mutexHashMap[id].Lock()
+	defer c.mutexHashMap[id].Unlock()
 
 	if val, ok := c.hashMap[id]; ok {
-		slog.Debug("gave a newly generated hash", slog.String("hash", base64.RawStdEncoding.EncodeToString(val)))
+		slog.Debug("gave a newly generated hash", slog.String("hash", val))
 		return val
 	}
 
-	c.hashMap[id] = argon2.IDKey([]byte(id), c.salt, 1, 64*1024, 4, 32)
-	slog.Debug("generated hash", slog.String("hash", base64.RawStdEncoding.EncodeToString(c.hashMap[id])))
+	c.hashMap[id] = base64.RawStdEncoding.EncodeToString(argon2.IDKey([]byte(id), c.salt, 1, 64*1024, 4, 32))
+	slog.Debug("generated hash", slog.String("hash", c.hashMap[id]))
 	return c.hashMap[id]
 }
+
+func (c *ClientCache) GetLikeStatus(id string, page string) bool {
+	if _, ok := c.likePageMap[page]; !ok {
+		return false
+	}
+	_, ok := c.likePageMap[page][c.GetHash(id)]
+	return ok
+}
+
+func (c *ClientCache) LikeOn(id string, page string) (alreadyLiked bool) {
+	if _, ok := c.mutexLikeMap[id]; !ok {
+		c.mutexLikeMap[id] = &sync.Mutex{}
+	}
+	c.mutexLikeMap[id].Lock()
+	defer c.mutexLikeMap[id].Unlock()
+
+	hash := c.GetHash(id)
+
+	if userSet, ok := c.likePageMap[page]; ok {
+		_, alreadyLiked = userSet[hash]
+		c.likePageMap[page][hash] = struct{}{}
+		return
+	}
+
+	c.likePageMap[page] = make(map[string]struct{})
+	c.likePageMap[page][hash] = struct{}{}
+	return
+}
+
+func (c *ClientCache) LikeOff(id string, page string) (alreadyUnliked bool) {
+	if _, ok := c.mutexLikeMap[id]; !ok {
+		c.mutexLikeMap[id] = &sync.Mutex{}
+	}
+	c.mutexLikeMap[id].Lock()
+	defer c.mutexLikeMap[id].Unlock()
+
+	if _, ok := c.likePageMap[page]; !ok {
+		return true
+	}
+	hash := c.GetHash(id)
+	if _, ok := c.likePageMap[page][hash]; !ok {
+		return true
+	}
+
+	delete(c.likePageMap[page], hash)
+	return false
+}
diff --git a/internal/router/lang-blog-title.go b/internal/router/lang-blog-title.go
index 5b80ec8..bafb0d2 100644
--- a/internal/router/lang-blog-title.go
+++ b/internal/router/lang-blog-title.go
@@ -24,7 +24,6 @@ func Lang_Blog_Title(l map[string]*locale.LocaleConfig, langs []string, b2Client
 	return func(c *fiber.Ctx) error {
 		ip := c.IP()
 		slog.Debug("client entering blog page", slog.String("ip", ip), slog.String("page", c.Path()))
-		go CCache.GetHash(ip)
 
 		lang := c.Params("lang")
 		if !slices.Contains(langs, lang) {