Add support for filtering IDs when rendering

2 files changed, 34 insertions, 6 deletions

diff --git a/CHANGELOG.org b/CHANGELOG.org
index eda366b..936aea2 100644
--- a/CHANGELOG.org
+++ b/CHANGELOG.org
@@ -1,5 +1,10 @@
 #+title: Org-ZK Changelog
 
+* Unreleased
+
+- Add support for filtering rendering by ID, as that is the most time-consuming
+  part.
+
 * Org-ZK 0.2.0.0
 
 - Support org bibliography file for bibliographic notes in the Zettelkasten.
diff --git a/src/Main.hs b/src/Main.hs
index 3a87cff..ea3cc64 100644
--- a/src/Main.hs
+++ b/src/Main.hs
@@ -1,3 +1,5 @@
+{-# LANGUAGE OverloadedRecordDot #-}
+
 -- |
 -- Module      : Main
 -- Description : Command-line interface for org-zk
@@ -29,6 +31,7 @@ module Main where
 
 import Control.Exception (ioError)
 import Control.Logging
+import Data.Map.Strict (intersection)
 import qualified Data.Text as T
 import Data.Version (showVersion)
 import Paths_org_zk (version)
@@ -223,7 +226,9 @@ data Options = Options
     -- | Csl FILE
     optCsl :: Maybe FilePath,
     -- | Index FILE (default: org-zettelkasten-index)
-    optIndex :: Maybe FilePath,
+    optIndexFile :: Maybe FilePath,
+    -- | Only process these indices
+    optIndex :: [ZettelId],
     -- | output DIR
     optOutput :: Maybe FilePath,
     -- | Verbose output while processing files
@@ -243,7 +248,8 @@ defaultOptions =
     { optBibliography = Nothing,
       optOrgBibliography = Nothing,
       optCsl = Nothing,
-      optIndex = Nothing,
+      optIndexFile = Nothing,
+      optIndex = [],
       optOutput = Nothing,
       optVerbose = 0,
       optQuiet = False,
@@ -251,6 +257,9 @@ defaultOptions =
       optShowHelp = False
     }
 
+parseIdList :: Text -> [ZettelId]
+parseIdList = fmap ZettelId . T.splitOn ","
+
 options :: [OptDescr (Options -> Options)]
 options =
   [ Option
@@ -264,15 +273,21 @@ options =
       (ReqArg (\f opts -> opts {optCsl = Just f}) "FILE")
       "Csl FILE",
     Option
+      ['f']
+      ["index-file"]
+      (ReqArg (\f opts -> opts {optIndexFile = Just f}) "FILE")
+      "Index FILE (default: org-zettelkasten-index)",
+    Option
       ['h']
       ["help"]
       (NoArg (\opts -> opts {optShowHelp = True}))
       "Show this help menu",
     Option
       ['i']
-      ["index"]
-      (ReqArg (\f opts -> opts {optIndex = Just f}) "FILE")
-      "Index FILE (default: org-zettelkasten-index)",
+      ["id"]
+      (ReqArg (\f opts -> opts {optIndex = opts.optIndex
+                                 ++ parseIdList (T.pack f)}) "ID")
+      "Only process these IDs",
     Option
       ['o']
       ["output"]
@@ -312,6 +327,14 @@ compilerOpts argv =
     (o, n, []) -> return (foldl' (flip id) defaultOptions o, n)
     (_, _, errs) -> ioError (userError (concat errs ++ usageInfo headerOpts options))
 
+filterWithIds :: [ZettelId] -> ZettelGraph -> ZettelGraph
+filterWithIds [] zg = zg
+filterWithIds ids (ZettelGraph zidMap bibMap) =
+  ZettelGraph (intersection zidMap zidMapFilter) (intersection bibMap bibMapFilter)
+  where
+    zidMapFilter = fromList $ map (\x -> (x, ())) ids
+    bibMapFilter = fromList $ map (\(ZettelId t) -> (BibId t, ())) ids
+
 main :: IO ()
 main = withStderrLogging $ do
   (zkOpts, fl) <- getArgs >>= compilerOpts
@@ -345,4 +368,4 @@ main = withStderrLogging $ do
     )
     (optBibliography zkOpts)
     (fromMaybe "output" (optOutput zkOpts))
-    (pipeline graph)
+    (filterWithIds (optIndex zkOpts) $ pipeline graph)