#!/bin/bash
#
# This source file is part of the Swift.org open source project
#
# Copyright (c) 2021 Apple Inc. and the Swift project authors
# Licensed under Apache License v2.0 with Runtime Library Exception
#
# See https://swift.org/LICENSE.txt for license information
# See https://swift.org/CONTRIBUTORS.txt for Swift project authors
#

# A `realpath` alternative using the default C implementation.
filepath() {
    [[ $1 = /* ]] && echo "$1" || echo "$PWD/${1#./}"
}

# First get the absolute path to this file so we can get the absolute file path to the Swift-DocC root source dir.
DOCC_ROOT="$(dirname $(dirname $(filepath $0)))"
DOCS_DIR="$DOCC_ROOT"/.build/docs
DOCS_BUILD_DIR="$DOCS_DIR/.docc-build"
SGFS_DIR="$DOCS_DIR"/SGFs

DOCC_CMD=preview
FRAMEWORK="SwiftDocC"

# Process command line arguments
while test $# -gt 0; do
  case "$1" in
    --help)
      echo
      echo "Usage: $(basename $0) [SwiftDocC|SwiftDocCUtilities|DocC] [-h] [--convert-only]"
      echo "Builds the given framework and converts or previews the documentation"
      echo "Note: To preview you must set the \`DOCC_HTML_DIR\` with a path to a documentation template.
      
      --help: print this message
      --convert-only: Builds the documentation but does not start a preview server"
      echo
      exit 0
      ;;
    --convert-only)
      DOCC_CMD=convert
      shift
      ;;
    *)
      FRAMEWORK="$1"
      shift
      ;;
  esac
done

# Create the output directory for the symbol graphs if needed.
mkdir -p "$DOCS_DIR"
mkdir -p "$SGFS_DIR"
rm -f $SGFS_DIR/*.*

case $FRAMEWORK in
  "SwiftDocC")

    # Generate symbol graph files for SwiftDocC
    swift build --package-path "$DOCC_ROOT" \
      --target SwiftDocC \
      -Xswiftc -emit-symbol-graph \
      -Xswiftc -emit-symbol-graph-dir -Xswiftc "$SGFS_DIR"
    
    echo
    
    # Delete the symbol graph files from dependences by looking for
    # those without a 'SwiftDocC' prefix.
    find "$SGFS_DIR" -type f ! -name 'SwiftDocC*' -delete
  
    echo
    
    # Compile the documentation and the symbol graph data.
    swift run docc $DOCC_CMD "$DOCC_ROOT/Sources/SwiftDocC/SwiftDocC.docc" \
      --experimental-enable-custom-templates \
      --fallback-display-name SwiftDocC \
      --fallback-bundle-identifier org.swift.SwiftDocC \
      --fallback-bundle-version 1.0.0 \
      --additional-symbol-graph-dir "$SGFS_DIR" \
      --output-path "$DOCS_BUILD_DIR"
  ;;
  
  "SwiftDocCUtilities")

    # Generate symbol graph files for SwiftDocCUtilities
    swift build --package-path "$DOCC_ROOT" \
      --target SwiftDocCUtilities \
      -Xswiftc -emit-symbol-graph \
      -Xswiftc -emit-symbol-graph-dir -Xswiftc "$SGFS_DIR"

    echo
    
    # Delete the symbol graph files from dependences by looking for
    # those without a 'SwiftDocCUtilities' prefix.
    find "$SGFS_DIR" -type f ! -name 'SwiftDocCUtilities*' -delete
    
    echo
    
    # Compile the documentation and the symbol graph data.
    swift run docc $DOCC_CMD "$DOCC_ROOT/Sources/SwiftDocCUtilities/SwiftDocCUtilities.docc" \
      --experimental-enable-custom-templates \
      --fallback-display-name SwiftDocCUtilities \
      --fallback-bundle-identifier org.swift.SwiftDocCUtilities \
      --fallback-bundle-version 1.0.0 \
      --additional-symbol-graph-dir "$SGFS_DIR" \
      --output-path $DOCS_BUILD_DIR
  ;;
  
    "DocC")

    # Compile the documentation
    swift run docc $DOCC_CMD "$DOCC_ROOT/Sources/docc/DocCDocumentation.docc" \
      --experimental-enable-custom-templates \
      --output-path $DOCS_BUILD_DIR
  ;;
  
  *)
    echo
    echo "Error: Unknown module '$FRAMEWORK'. Preview is supported only for SwiftDocC, SwiftDocCUtilities, or DocC."
    exit 0
  ;;
esac
