1 files changed, 74 insertions, 0 deletions

diff --git a/config.go b/config.go
new file mode 100644
index 0000000..d9a2e30
--- /dev/null
+++ b/config.go
@@ -0,0 +1,74 @@
+package main
+
+import (
+        "encoding/base64"
+        "encoding/json"
+        "log"
+        "net/url"
+        "os"
+        "regexp"
+)
+
+type userToken struct {
+        Hash []byte `json:"hash"`
+        Salt []byte `json:"salt"`
+}
+
+type config struct {
+        CalendarURL url.URL              `json:"calendar_url"`
+        Ignore      ignoreRules          `json:"ignore"`
+        Port        string               `json:"port"`
+        UserTokens  map[string]userToken `json:"user_tokens"`
+}
+
+type ignoreRules struct {
+        LocationRegexes []regexp.Regexp `json:"location_regexes"`
+        SummaryRegexes  []regexp.Regexp `json:"summary_regexes"`
+}
+
+func printConfig(cfg *config) {
+        b64 := base64.StdEncoding
+
+        log.Print("Loaded configuration: ")
+        log.Print("  HTTP Port:  ", cfg.Port)
+        log.Print("  User Tokens:")
+        for user, token := range cfg.UserTokens {
+                log.Print("    User ", user, ":")
+                log.Print("      Hash:  ", b64.EncodeToString(token.Hash))
+                log.Print("      Salt:  ", b64.EncodeToString(token.Salt))
+        }
+        if len(cfg.UserTokens) == 0 {
+                log.Print("    <no users configured>")
+        }
+        log.Print("  Ignoring:")
+        for _, entry := range cfg.Ignore.LocationRegexes {
+                log.Printf("    Events with locations matching %s", entry.String())
+        }
+        for _, entry := range cfg.Ignore.SummaryRegexes {
+                log.Printf("    Events with summaries matching %s", entry.String())
+        }
+        if len(cfg.Ignore.LocationRegexes)+len(cfg.Ignore.SummaryRegexes) == 0 {
+                log.Printf("    <no ignore rules configured>")
+        }
+}
+
+func loadConfigFrom(filename string) config {
+        bytes, err := os.ReadFile(filename)
+        if err != nil {
+                log.Fatal("Could not read config file (at ", filename, ")")
+        }
+        var cfg config
+        if err = json.Unmarshal(bytes, &cfg); err != nil {
+                log.Fatalln("Could not parse config file:", err)
+        }
+        return cfg
+}
+
+func loadConfig() config {
+        configFile := os.Getenv("CONFIG_FILE")
+        if configFile == "" {
+                log.Fatal("Environment variable CONFIG_FILE not specified")
+        }
+        log.Print("Loading configuration from ", configFile)
+        return loadConfigFrom(configFile)
+}