Add support for shortcode-like feature in posts

admin-app/app.go

@@ -1,18 +1,27 @@
 package admin_app
 
 import (
+	"log"
+
 	"github.com/gin-gonic/gin"
 	"github.com/matheusgomes28/urchin/common"
 	"github.com/matheusgomes28/urchin/database"
+	"github.com/matheusgomes28/urchin/plugins"
+	lua "github.com/yuin/gopher-lua"
 )
 
-func SetupRoutes(app_settings common.AppSettings, database database.Database) *gin.Engine {
+func SetupRoutes(app_settings common.AppSettings, database database.Database, shortcode_handlers map[string]*lua.LState, hooks map[string]plugins.Hook) *gin.Engine {
 
 	r := gin.Default()
 	r.MaxMultipartMemory = 1
 
+	post_hook, ok := hooks["add_post"]
+	if !ok {
+		log.Fatalf("could not find add_post hook")
+	}
+
 	r.GET("/posts/:id", getPostHandler(database))
-	r.POST("/posts", postPostHandler(database))
+	r.POST("/posts", postPostHandler(database, shortcode_handlers, post_hook.(plugins.PostHook)))
 	r.PUT("/posts", putPostHandler(database))
 	r.DELETE("/posts/:id", deletePostHandler(database))
 

admin-app/post.go

@@ -4,12 +4,15 @@ import (
 	"encoding/json"
 	"fmt"
 	"net/http"
+	"regexp"
 	"strings"
 
 	"github.com/gin-gonic/gin"
 	"github.com/matheusgomes28/urchin/common"
 	"github.com/matheusgomes28/urchin/database"
+	"github.com/matheusgomes28/urchin/plugins"
 	"github.com/rs/zerolog/log"
+	lua "github.com/yuin/gopher-lua"
 )
 
 func getPostHandler(database database.Database) func(*gin.Context) {
@@ -37,7 +40,7 @@ func getPostHandler(database database.Database) func(*gin.Context) {
 	}
 }
 
-func postPostHandler(database database.Database) func(*gin.Context) {
+func postPostHandler(database database.Database, shortcode_handlers map[string]*lua.LState, post_hook plugins.PostHook) func(*gin.Context) {
 	return func(c *gin.Context) {
 		var add_post_request AddPostRequest
 		if c.Request.Body == nil {
@@ -57,13 +60,25 @@ func postPostHandler(database database.Database) func(*gin.Context) {
 		if err != nil {
 			log.Error().Msgf("failed to add post required data is missing: %v", err)
 			c.JSON(http.StatusBadRequest, common.ErrorRes("missing required data", err))
-			return
 		}
 
+		// TODO : Move this into the plugin
+		altered_post := post_hook.UpdatePost(add_post_request.Title, add_post_request.Content, add_post_request.Excerpt, shortcode_handlers)
+
+		// transformed_content, err := transformContent(add_post_request.Content, shortcode_handlers)
+		// if err != nil {
+		// 	log.Warn().Msgf("could not transform post: %v", err)
+		// 	c.JSON(http.StatusBadRequest, gin.H{
+		// 		"error": "invalid request body",
+		// 		"msg":   err.Error(),
+		// 	})
+		// 	return
+		// }
+
 		id, err := database.AddPost(
-			add_post_request.Title,
-			add_post_request.Excerpt,
-			add_post_request.Content,
+			altered_post.Title,
+			altered_post.Excerpt,
+			altered_post.Content,
 		)
 		if err != nil {
 			log.Error().Msgf("failed to add post: %v", err)
@@ -151,3 +166,86 @@ func checkRequiredData(addPostRequest AddPostRequest) error {
 
 	return nil
 }
+
+// partitionString will partition the strings by
+// removing the given ranges
+func partitionString(text string, indexes [][]int) []string {
+
+	if len(text) == 0 {
+		return []string{}
+	}
+
+	partitions := make([]string, 0)
+	start := 0
+	for _, window := range indexes {
+		partitions = append(partitions, text[start:window[0]])
+		start = window[1]
+	}
+
+	partitions = append(partitions, text[start:len(text)-1])
+	return partitions
+}
+
+func shortcodeToMarkdown(shortcode string, shortcode_handlers map[string]*lua.LState) (string, error) {
+	key_value := strings.Split(shortcode, ":")
+
+	key := key_value[0]
+	values := key_value[1:]
+
+	if handler, found := shortcode_handlers[key]; found {
+
+		// Need to quote all values for a valid lua syntax
+		quoted_values := make([]string, 0)
+		for _, value := range values {
+			quoted_values = append(quoted_values, fmt.Sprintf("%q", value))
+		}
+
+		err := handler.DoString(fmt.Sprintf(`result = HandleShortcode({%s})`, strings.Join(quoted_values, ",")))
+		if err != nil {
+			return "", fmt.Errorf("error running %s shortcode: %v", key, err)
+		}
+
+		value := handler.GetGlobal("result")
+		if ret_type := value.Type().String(); ret_type != "string" {
+			return "", fmt.Errorf("error running %s shortcode: invalid return type %s", key, ret_type)
+		} else if ret_type == "" {
+			return "", fmt.Errorf("error running %s shortcode: returned empty string", key)
+		}
+
+		return value.String(), nil
+	}
+
+	return "", fmt.Errorf("unsupported shortcode: %s", key)
+}
+
+func transformContent(content string, shortcode_handlers map[string]*lua.LState) (string, error) {
+	// Find all the occurences of {{ and }}
+	regex, _ := regexp.Compile(`{{[\w.-]+(:[\w.-]+)+}}`)
+
+	shortcodes := regex.FindAllStringIndex(content, -1)
+	if len(shortcodes) == 0 {
+		return content, nil
+	}
+
+	partitions := partitionString(content, shortcodes)
+
+	builder := strings.Builder{}
+	i := 0
+
+	for i, shortcode := range shortcodes {
+		builder.WriteString(partitions[i])
+
+		markdown, err := shortcodeToMarkdown(content[shortcode[0]+2:shortcode[1]-2], shortcode_handlers)
+		if err != nil {
+			log.Error().Msgf("%v", err)
+			markdown = ""
+		}
+		builder.WriteString(markdown)
+	}
+
+	// Guaranteed to have +1 than the number of
+	// shortcodes by algorithm
+	builder.WriteString(partitions[i+1])
+
+	return builder.String(), nil
+}

app/app.go

@@ -44,7 +44,6 @@ func SetupRoutes(app_settings common.AppSettings, database database.Database) *g
 
 	// Where all the static files (css, js, etc) are served from
 	r.Static("/static", "./static")
-
 	return r
 }
 

app/post.go

@@ -2,6 +2,7 @@ package app
 
 import (
 	"bytes"
+	"fmt"
 	"net/http"
 
 	"github.com/gin-gonic/gin"
@@ -54,7 +55,7 @@ func postHandler(c *gin.Context, app_settings common.AppSettings, database datab
 			c.JSON(http.StatusBadRequest, gin.H{"error": "Invalid post ID"})
 		}
 
-		return nil, err
+		return nil, fmt.Errorf("invalid post id")
 	}
 
 	// Get the post with the ID

cmd/urchin-admin/main.go

@@ -9,9 +9,28 @@ import (
 	admin_app "github.com/matheusgomes28/urchin/admin-app"
 	"github.com/matheusgomes28/urchin/common"
 	"github.com/matheusgomes28/urchin/database"
+	"github.com/matheusgomes28/urchin/plugins"
 	"github.com/rs/zerolog/log"
+	lua "github.com/yuin/gopher-lua"
 )
 
+func loadShortcodeHandlers(shortcodes []common.Shortcode) (map[string]*lua.LState, error) {
+	shortcode_handlers := make(map[string]*lua.LState, 0)
+	for _, shortcode := range shortcodes {
+		// Read the LUA state
+		state := lua.NewState()
+		err := state.DoFile(shortcode.Plugin)
+		// TODO : check that the function HandleShortcode(args)
+		//        exists and returns the correct type
+		if err != nil {
+			return map[string]*lua.LState{}, fmt.Errorf("could not load shortcode %s: %v", shortcode.Name, err)
+		}
+		shortcode_handlers[shortcode.Name] = state
+	}
+
+	return shortcode_handlers, nil
+}
+
 func main() {
 	// sets zerolog as the main logger
 	// in this APP
@@ -46,8 +65,29 @@ func main() {
 		os.Exit(-1)
 	}
 
-	r := admin_app.SetupRoutes(app_settings, database)
-	err = r.Run(fmt.Sprintf(":%d", app_settings.AdminPort))
+	shortcode_handlers, err := loadShortcodeHandlers(app_settings.Shortcodes)
+	if err != nil {
+		log.Error().Msgf("%v", err)
+		os.Exit(-1)
+	}
+
+	// TODO : we probably want to refactor loadShortcodeHandler
+	// TODO : into loadPluginHandlers instead
+
+	post_hook := plugins.PostHook{}
+	image_plugin := plugins.Plugin{
+		ScriptName: "img",
+		Id:         "img-plugin",
+	}
+	post_hook.Register(image_plugin)
+
+	// img, _ := shortcode_handlers["img"]
+	hooks_map := map[string]plugins.Hook{
+		"add_post": post_hook,
+	}
+
+	r := admin_app.SetupRoutes(app_settings, database, shortcode_handlers, hooks_map)
+	err = r.Run(fmt.Sprintf(":%d", app_settings.WebserverPort))
 	if err != nil {
 		log.Error().Msgf("could not run app: %v", err)
 		os.Exit(-1)

common/app_settings.go

@@ -8,19 +8,27 @@ type Navbar struct {
 	Links []Link `toml:"links"`
 }
 
+type Shortcode struct {
+	// name for the shortcode {{name:...:...}}
+	Name string `toml:"name"`
+	// The lua plugin path
+	Plugin string `toml:"plugin"`
+}
+
 type AppSettings struct {
-	DatabaseAddress  string `toml:"database_address"`
-	DatabasePort     int    `toml:"database_port"`
-	DatabaseUser     string `toml:"database_user"`
-	DatabasePassword string `toml:"database_password"`
-	DatabaseName     string `toml:"database_name"`
-	WebserverPort    int    `toml:"webserver_port"`
-	AdminPort        int    `toml:"admin_port"`
-	ImageDirectory   string `toml:"image_dir"`
-	CacheEnabled     bool   `toml:"cache_enabled"`
-	RecaptchaSiteKey string `toml:"recaptcha_sitekey,omitempty"`
-	RecaptchaSecret  string `toml:"recaptcha_secret,omitempty"`
-	AppNavbar        Navbar `toml:"navbar"`
+	DatabaseAddress  string      `toml:"database_address"`
+	DatabasePort     int         `toml:"database_port"`
+	DatabaseUser     string      `toml:"database_user"`
+	DatabasePassword string      `toml:"database_password"`
+	DatabaseName     string      `toml:"database_name"`
+	WebserverPort    int         `toml:"webserver_port"`
+	AdminPort        int         `toml:"admin_port"`
+	ImageDirectory   string      `toml:"image_dir"`
+	CacheEnabled     bool        `toml:"cache_enabled"`
+	RecaptchaSiteKey string      `toml:"recaptcha_sitekey,omitempty"`
+	RecaptchaSecret  string      `toml:"recaptcha_secret,omitempty"`
+	AppNavbar        Navbar      `toml:"navbar"`
+	Shortcodes       []Shortcode `toml:"shortcodes"`
 }
 
 func ReadConfigToml(filepath string) (AppSettings, error) {

database/database.go

@@ -167,7 +167,7 @@ func (db SqlDatabase) GetPage(link string) (common.Page, error) {
 		return common.Page{}, err
 	}
 	defer func() {
-		err = errors.Join(rows.Close())
+		err = errors.Join(err, rows.Close())
 	}()
 
 	page := common.Page{}

go.mod

@@ -14,6 +14,7 @@ require (
 	github.com/pressly/goose/v3 v3.19.2
 	github.com/rs/zerolog v1.31.0
 	github.com/stretchr/testify v1.8.4
+	github.com/yuin/gopher-lua v1.1.1
 	github.com/zutto/shardedmap v0.0.0-20180201164343-415202d0910e
 )
 

go.sum

@@ -446,6 +446,8 @@ github.com/ydb-platform/ydb-go-genproto v0.0.0-20240126124512-dbb0e1720dbf h1:ck
 github.com/ydb-platform/ydb-go-genproto v0.0.0-20240126124512-dbb0e1720dbf/go.mod h1:Er+FePu1dNUieD+XTMDduGpQuCPssK5Q4BjF+IIXJ3I=
 github.com/ydb-platform/ydb-go-sdk/v3 v3.55.1 h1:Ebo6J5AMXgJ3A438ECYotA0aK7ETqjQx9WoZvVxzKBE=
 github.com/ydb-platform/ydb-go-sdk/v3 v3.55.1/go.mod h1:udNPW8eupyH/EZocecFmaSNJacKKYjzQa7cVgX5U2nc=
+github.com/yuin/gopher-lua v1.1.1 h1:kYKnWBjvbNP4XLT3+bPEwAXJx262OhaHDWDVOPjL46M=
+github.com/yuin/gopher-lua v1.1.1/go.mod h1:GBR0iDaNXjAgGg9zfCvksxSRnQx76gclCIb7kdAd1Pw=
 github.com/zutto/shardedmap v0.0.0-20180201164343-415202d0910e h1:zqDzvgPMqbfHrSXOo2igl2H9q2RoY5l7z1YpaPGMuog=
 github.com/zutto/shardedmap v0.0.0-20180201164343-415202d0910e/go.mod h1:NKD0ezOo5cN3cWU7CGigl5LQhm3gNi+jaOplrVspLjc=
 go.etcd.io/bbolt v1.3.3/go.mod h1:IbVyRI1SCnLcuJnV2u8VeU0CEYM7e686BmAb1XKL+uU=

plugins/image_shortcode.lua

@@ -0,0 +1,11 @@
+function HandleShortcode(arguments)
+    if #arguments == 1 then
+        local image_src = string.format("/data/images/%s", arguments[1])
+        return string.format("![image](%s)", image_src)
+    elseif #arguments == 2 then
+        local image_src = string.format("/data/images/%s", arguments[1])
+        return string.format("![%s](%s)", arguments[2], image_src)
+    else
+        return ""
+    end
+end

plugins/table_shortcode.lua

@@ -0,0 +1,7 @@
+function HandleShortcode(arguments)
+    if #arguments ~= 2 then
+        return ""
+    end
+
+    return "\n| Tables   |      Are      |  Cool |\n|----------|:-------------:|------:|\n| col 1 is |  left-aligned | $1600 |\n| col 2 is |    centered   |   $12 |\n| col 3 is | right-aligned |    $1 |\n"
+end