{-
 - Copyright (C) 2023 University of Luxembourg
 -
 - Licensed under the Apache License, Version 2.0 (the "License"); you may not
 - use this file except in compliance with the License. You may obtain a copy
 - of the License from the LICENSE file in this repository, or at:
 -
 - http://www.apache.org/licenses/LICENSE-2.0
 -
 - Unless required by applicable law or agreed to in writing, software
 - distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 - WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 - License for the specific language governing permissions and limitations
 - under the License.
 -}

{-# LANGUAGE TemplateHaskell #-}
{-# LANGUAGE ApplicativeDo #-}
{-# LANGUAGE RecordWildCards #-}

-- | Separated-out main types of the deployment scriptage.
module Types where

import Control.Monad.Trans.State.Lazy
import Data.List.NonEmpty
import qualified Data.Map as M
import qualified Data.Set as S
import qualified Data.Yaml as Y
import Lens.Micro.TH
import Options.Applicative
import qualified Text.Mustache as Mu
import qualified Text.Pandoc.Definition

-- | Information about a single deployed page (with metadata etc).
data PageInfo =
  PageInfo
    { _pagePath :: FilePath -- ^ original path to the markdown file
    , _pageMeta :: Y.Value -- ^ YAML metadata extracted from the file
    , _pageDoc :: Text.Pandoc.Definition.Pandoc -- ^ Page data
    }
  deriving (Show)

makeLenses ''PageInfo

-- | Complete internal state of the deployment process that holds all data
data SiteState =
  SiteState
    -- | Map of page mounts to `PageInfo`
    { _pages :: M.Map FilePath PageInfo
    -- | Map of redirects (from -> to)
    , _redirects :: M.Map FilePath FilePath
    -- | Map of tags, assigning to each tag sequence a list of
    -- tagged page mounts
    , _htags :: M.Map [String] [FilePath]
    -- | Map of tags, assigning to each tag sequence a list of tagged page
    -- mounts. This one is expanded (tags imply parent categories).
    , _ehtags :: M.Map [String] [FilePath]
    -- | Map of "short" tags to expanded human-friendly names
    , _tagNames :: M.Map String String
    -- | List of installed files (enables sharing)
    , _installs :: S.Set (String, FilePath)
    -- | List of installed files (prevents overwriting)
    , _targets :: S.Set FilePath
    -- | Map of Mustache templates organized by template search path (within
    -- the template directory)
    , _templates :: M.Map FilePath Mu.Template
    , _outputDir :: FilePath -- ^ Directory for output
    , _searchDataOut :: Maybe FilePath -- ^ File to write the searchable versions of pages to (as JSON)
    , _assetDir :: FilePath -- ^ Directory for output
    , _sourceDirs :: [FilePath] -- ^ Path to page source data
    , _notSourceDirs :: [FilePath] -- ^ Subdirectories of source dirs where pages should not be sourced
    , _templateDir :: FilePath -- ^ Path to template directory
    , _defaultTemplate :: FilePath -- ^ Name of the default template
    , _redirectTemplate :: FilePath -- ^ Name of the template for redirect pages
    , _tagTemplate :: FilePath -- ^ Name of the template for category pages
    , _listTemplate :: FilePath -- ^ Name of the template for listing pages
    , _timestampSuffix :: FilePath -- ^ File to search for a timestamp (e.g., if the prefix is ".ts", a timestamp for file "page.md" will be looked for in "page.md.ts"). These are best autogenerated with a script that sources the data from git or so.
    , _urlBase :: FilePath -- ^ "Root route" to prepend to all absolute links.
    , _dumpFinalState :: Bool -- ^ Triggers printing out the structure when the processing finishes.
    }
  deriving (Show)

makeLenses ''SiteState

-- | Monad for running the site generator.
type Site a = StateT SiteState IO a

-- | Parser for commandline options
siteOptions' :: Parser SiteState
siteOptions' = do
  _outputDir <-
    strOption $
    long "output" <>
    short 'd' <>
    help "Directory to render the site to" <> value "_site" <> showDefault
  _searchDataOut <-
    Just <$>
    (strOption $
     long "search-data-output" <>
     help "Output JSON with searchable page data to this file") <|>
    pure Nothing
  _assetDir <-
    strOption $
    long "assets" <>
    short 'a' <>
    help "Assets directory to be copied verbatim" <>
    value "assets" <> showDefault
  _sourceDirs <-
    fmap (maybe ["pages"] toList . nonEmpty) . many . strOption $
    long "source-directory" <>
    short 's' <>
    help
      "Path to the directory with source data (possibly multiple paths, defaults to a single directory \"pages\")"
  _notSourceDirs <-
    fmap (maybe ["assets"] toList . nonEmpty) . many . strOption $
    long "exclude-source-directory" <>
    help
      "Names of subdirectories of the sources that should never be used for sourcing pages (possibly multiple directory names, defaults to a single directory \"assets\")"
  _templateDir <-
    strOption $
    long "template-directory" <>
    help "Path to the directory with templates" <>
    value "templates" <> showDefault
  _defaultTemplate <-
    strOption $
    long "default-template" <>
    help "Default template to use for stuff (found in templates directory)" <>
    value "default.html" <> showDefault
  _redirectTemplate <-
    strOption $
    long "redirect-template" <>
    help "Template for making redirect pages" <>
    value "redirect.html" <> showDefault
  _tagTemplate <-
    strOption $
    long "tag-template" <>
    help "Template for making category view pages" <>
    value "tag.html" <> showDefault
  _listTemplate <-
    strOption $
    long "list-template" <>
    help "Template for making tag-listing pages" <>
    value "list.html" <> showDefault
  _urlBase <-
    strOption $
    long "url-base" <>
    short 'u' <> help "Base absolute URL" <> value "/" <> showDefault
  _timestampSuffix <-
    strOption $
    long "timestamp-prefix" <>
    help "Timestamp file suffix for markdowns" <>
    value ".timestamp" <> showDefault
  _dumpFinalState <-
    switch $
    long "dump-state" <>
    short 'D' <>
    help "Print out the complete internal state after the site is built"
  pure
    SiteState
      { _pages = M.empty
      , _redirects = M.empty
      , _htags = M.empty
      , _ehtags = M.empty
      , _tagNames = M.empty
      , _installs = S.empty
      , _targets = S.empty
      , _templates = M.empty
      , ..
      }

-- | ParserInfo for commandline options
siteOptions =
  info
    (siteOptions' <**> helper)
    (fullDesc <>
     progDesc "Build a R3 Cards-like site" <>
     header "site - the R3 site builder")