#!/bin/bash

set_setting_value() {
  # Function for editing settings
  # USAGE: set_setting_value "$setting_file" "$setting_name" "$new_setting_value" "$system" "$section_name(optional)"

  local setting_name_to_change=$(sed -e 's^\\^\\\\^g;s^`^\\`^g' <<< "$2")
  local setting_value_to_change=$(sed -e 's^\\^\\\\^g;s^`^\\`^g' <<< "$3")
  local current_section_name=$(sed -e 's/%/\\%/g' <<< "$5")

  case $4 in

    "retrodeck" | "citra" | "melonds" | "yuzu" )
      if [[ -z $current_section_name ]]; then
        sed -i 's^\^'"$setting_name_to_change"'=.*^'"$setting_name_to_change"'='"$setting_value_to_change"'^' "$1"
      else
        sed -i '\^\['"$current_section_name"'\]^,\^\^'"$setting_name_to_change"'=^s^\^'"$setting_name_to_change"'=.*^'"$setting_name_to_change"'='"$setting_value_to_change"'^' "$1"
      fi
      if [[ "$4" == "retrodeck" && ("$current_section_name" == "" || "$current_section_name" == "paths" || "$current_section_name" == "options") ]]; then # If a RetroDECK setting is being changed, also write it to memory for immediate use
        declare -g "$setting_name_to_change=$setting_value_to_change"
      fi
      ;;

    "retroarch" )
      if [[ -z $current_section_name ]]; then
        sed -i 's^\^'"$setting_name_to_change"' = \".*\"^'"$setting_name_to_change"' = \"'"$setting_value_to_change"'\"^' "$1"
      else
        sed -i '\^\['"$current_section_name"'\]^,\^\^'"$setting_name_to_change"' = ^s^\^'"$setting_name_to_change"' = \".*\"^'"$setting_name_to_change"' = \"'"$setting_value_to_change"'\"^' "$1"
      fi
      ;;

    "dolphin" | "duckstation" | "pcsx2" | "ppsspp" | "primehack" | "xemu" )
      if [[ -z $current_section_name ]]; then
        sed -i 's^\^'"$setting_name_to_change"' =.*^'"$setting_name_to_change"' = '"$setting_value_to_change"'^' "$1"
      else
        sed -i '\^\['"$current_section_name"'\]^,\^\^'"$setting_name_to_change"' =^s^\^'"$setting_name_to_change"' =.*^'"$setting_name_to_change"' = '"$setting_value_to_change"'^' "$1"
      fi
      ;;

    "rpcs3" | "vita3k" ) # This does not currently work for settings with a $ in them
      if [[ -z $current_section_name ]]; then
        sed -i 's^\^'"$setting_name_to_change"': .*^'"$setting_name_to_change"': '"$setting_value_to_change"'^' "$1"
      else
        sed -i '\^\['"$current_section_name"'\]^,\^\^'"$setting_name_to_change"'.*^s^\^'"$setting_name_to_change"': .*^'"$setting_name_to_change"': '"$setting_value_to_change"'^' "$1"
      fi
      ;;

    "cemu" )
      if [[ -z "$current_section_name" ]]; then
        xml ed -L -u "//$setting_name_to_change" -v "$setting_value_to_change" "$1"
      else
        xml ed -L -u "//$current_section_name/$setting_name_to_change" -v "$setting_value_to_change" "$1"
      fi
      ;;

    "es_settings" )
      sed -i 's^'"$setting_name_to_change"'" value=".*"^'"$setting_name_to_change"'" value="'"$setting_value_to_change"'"^' "$1"
      ;;

  esac
}

get_setting_name() {
  # Function for getting the setting name from a full setting line from a config file
  # USAGE: get_setting_name "$current_setting_line" $system

  local current_setting_line="$1"

  case $2 in

  "es_settings" )
    echo ''"$current_setting_line"'' | grep -o -P '(?<=name\=\").*(?=\" value)'
    ;;

  "rpcs3" | "vita3k" )
    echo "$current_setting_line" | grep -o -P "^\s*?.*?(?=\s?:\s?)" | sed -e 's/^[ \t]*//;s^\\ ^ ^g'
    ;;

  * )
    echo "$current_setting_line" | grep -o -P "^\s*?.*?(?=\s?=\s?)" | sed -e 's/^[ \t]*//;s^\\ ^ ^g;s^\\$^^'
    ;;

  esac
}

get_setting_value() {
# Function for getting the current value of a setting from a config file
# USAGE: get_setting_value $setting_file "$setting_name" $system $section (optional)

  local current_setting_name="$2"
  local current_section_name="$4"

  case $3 in

  "retrodeck" | "citra" | "melonds" | "yuzu" ) # For files with this syntax - setting_name=setting_value
    if [[ -z $current_section_name ]]; then
      echo $(grep -o -P "(?<=^$current_setting_name=).*" "$1")
    else
      sed -n -E '\^\['"$current_section_name"'\]^,\^\^'"$current_setting_name"'|\[^{ \^\['"$current_section_name"'\]^! { \^\^'"$current_setting_name"'^ p } }' "$1" | grep -o -P "(?<=^$current_setting_name=).*"
    fi
  ;;

  "retroarch" ) # For files with this syntax - setting_name = "setting_value"
    if [[ -z $current_section_name ]]; then
      echo $(grep -o -P "(?<=^$current_setting_name = \").*(?=\")" "$1")
    else
      sed -n -E '\^\['"$current_section_name"'\]^,\^\^'"$current_setting_name"'|\[^{ \^\['"$current_section_name"'\]^! { \^\^'"$current_setting_name"'^ p } }' "$1" | grep -o -P "(?<=^$current_setting_name = \").*(?=\")"
    fi
  ;;

  "dolphin" | "duckstation" | "pcsx2" | "ppsspp" | "primehack" | "xemu" ) # For files with this syntax - setting_name = setting_value
    if [[ -z $current_section_name ]]; then
      echo $(grep -o -P "(?<=^$current_setting_name = ).*" $1)
    else
      sed -n -E '\^\['"$current_section_name"'\]^,\^\^'"$current_setting_name"'|\[^{ \^\['"$current_section_name"'\]^! { \^\^'"$current_setting_name"'^ p } }' "$1" | grep -o -P "(?<=^$current_setting_name = ).*"
    fi
  ;;

  "rpcs3" | "vita3k" ) # For files with this syntax - setting_name: setting_value
    if [[ -z $current_section_name ]]; then
      echo $(grep -o -P "(?<=$current_setting_name: ).*" "$1")
    else
      sed -n '\^\['"$current_section_name"'\]^,\^\^'"$current_setting_name"'^{ \^\['"$current_section_name"'\]^! { \^\^'"$current_setting_name"'^ p } }' "$1" | grep -o -P "(?<=$current_setting_name: ).*"
    fi
  ;;

  "cemu" )
    if [[ -z "$current_section_name" ]]; then
      echo $(xml sel -t -v "//$current_setting_name" "$1")
    else
      echo $(xml sel -t -v "//$current_section_name/$current_setting_name" "$1")
    fi
  ;;

  "es_settings" )
    echo $(grep -o -P "(?<=$current_setting_name\" value=\").*(?=\")" "$1")
  ;;

  esac
}

add_setting_line() {
  # This function will add a setting line to a file. This is useful for dynamically generated config files where a setting line may not exist until the setting is changed from the default.
  # USAGE: add_setting_line $setting_file $setting_line $system $section (optional)

  local current_setting_line=$(sed -e 's^\\^\\\\^g;s^`^\\`^g' <<< "$2")
  local current_section_name=$(sed -e 's/%/\\%/g' <<< "$4")

  case $3 in

  * )
    if [[ -z $current_section_name ]]; then
      if [[ -f "$1" ]]; then
        sed -i '$ a '"$current_setting_line"'' "$1"
      else # If the file doesn't exist, sed add doesn't work for the first line
        echo "$current_setting_line" > "$1"
      fi
    else
      sed -i '/^\s*?\['"$current_section_name"'\]|\b'"$current_section_name"':$/a '"$current_setting_line"'' "$1"
    fi
    ;;

  esac
}

add_setting() {
  # This function will add a setting name and value to a file. This is useful for dynamically generated config files like Retroarch override files.
  # USAGE: add_setting $setting_file $setting_name $setting_value $system $section (optional)

  local current_setting_name=$(sed -e 's^\\^\\\\^g;s^`^\\`^g' <<< "$2")
  local current_setting_value=$(sed -e 's^\\^\\\\^g;s^`^\\`^g' <<< "$3")
  local current_section_name=$(sed -e 's/%/\\%/g' <<< "$5")

  case $4 in

  "retroarch" )
    if [[ -z $current_section_name ]]; then
      sed -i '$ a '"$current_setting_name"' = "'"$current_setting_value"'"' "$1"
    else
      sed -i '/^\s*?\['"$current_section_name"'\]|\b'"$current_section_name"':$/a '"$current_setting_name"' = "'"$current_setting_value"'"' "$1"
    fi
    ;;

  esac
}

delete_setting() {
  # This function will delete a setting line from a file. This is useful for dynamically generated config files like Retroarch override files
  # USAGE: delete_setting $setting_file $setting_name $system $section (optional)

  local current_setting_name=$(sed -e 's^\\^\\\\^g;s^`^\\`^g' <<< "$2")
  local current_section_name=$(sed -e 's/%/\\%/g' <<< "$4")

  case $3 in

  "retroarch" )
    if [[ -z $current_section_name ]]; then
      sed -i '\^'"$current_setting_name"'^d' "$1"
      sed -i '/^$/d' "$1" # Cleanup empty lines left behind
    fi
    ;;

  esac
}

disable_setting() {
  # This function will add a '#' to the beginning of a defined setting line, disabling it.
  # USAGE: disable_setting $setting_file $setting_line $system $section (optional)

  local current_setting_line="$2"
  local current_section_name="$4"

  case $3 in

  * )
    if [[ -z $current_section_name ]]; then
      sed -i -E 's^(\s*?)'"$current_setting_line"'^\1#'"$current_setting_line"'^' "$1"
    else
      sed -i -E '\^\['"$current_section_name"'\]|\b'"$current_section_name"':$^,\^\s*?'"$current_setting_line"'^s^(\s*?)'"$current_setting_line"'^\1#'"$current_setting_line"'^' "$1"
    fi
  ;;

  esac
}

enable_setting() {
  # This function will remove a '#' to the beginning of a defined setting line, enabling it.
  # USAGE: enable_setting $setting_file $setting_line $system $section (optional)

  local current_setting_line="$2"
  local current_section_name="$4"

  case $3 in

  * )
    if [[ -z $current_section_name ]]; then
      sed -i -E 's^(\s*?)#'"$current_setting_line"'^\1'"$current_setting_line"'^' "$1"
    else
      sed -i -E '\^\['"$current_section_name"'\]|\b'"$current_section_name"':$^,\^\s*?#'"$current_setting_line"'^s^(\s*?)#'"$current_setting_line"'^\1'"$current_setting_line"'^' "$1"
    fi
  ;;

  esac
}

disable_file() {
  # This function adds the suffix ".disabled" to the end of a file to prevent it from being used entirely.
  # USAGE: disable_file $file_name
  # NOTE: $filename can be a defined variable from global.sh or must have the full path to the file

  mv "$(realpath "$1")" "$(realpath "$1")".disabled
}

enable_file() {
  # This function removes the suffix ".disabled" to the end of a file to allow it to be used.
  # USAGE: enable_file $file_name
  # NOTE: $filename can be a defined variable from global.sh or must have the full path to the file and should not have ".disabled" as a suffix

  mv "$(realpath "$1".disabled)" "$(realpath "$(echo "$1" | sed -e 's/\.disabled//')")"
}

generate_single_patch() {
  # generate_single_patch $original_file $modified_file $patch_file $system

  local original_file="$1"
  local modified_file="$2"
  local patch_file="$3"
  local system="$4"

  if [[ -f "$patch_file" ]]; then
    rm "$patch_file" # Remove old patch file (maybe change this to create a backup instead?)
  fi

  while read -r current_setting_line; # Look for changes from the original file to the modified one
  do
    printf -v escaped_setting_line '%q' "$current_setting_line" # Take care of special characters before they mess with future commands
    escaped_setting_line=$(sed -E 's^\+^\\+^g' <<< "$escaped_setting_line") # Need to escape plus signs as well

    if [[ (! -z $current_setting_line) && (! $current_setting_line == "#!/bin/bash") && (! $current_setting_line == "[]") ]]; then # Ignore empty lines, empty arrays or Bash start lines
      if [[ ! -z $(grep -o -P "^\[.+?\]$" <<< "$current_setting_line") || ! -z $(grep -o -P "^\b.+?:$" <<< "$current_setting_line") ]]; then # Capture section header lines
        if [[ $current_setting_line =~ ^\[.+\] ]]; then # If normal section line
          action="section"
          current_section=$(sed 's^[][]^^g' <<< "$current_setting_line") # Remove brackets from section name
        elif [[ ! -z $(grep -o -P "^\b.+?:$" <<< "$current_setting_line") ]]; then # If RPCS3 section name
          action="section"
          current_section=$(sed 's^:$^^' <<< "$current_setting_line") # Remove colon from section name
        fi
      elif [[ (! -z "$current_section") ]]; then # If line is in a section...
        if [[ ! -z $(grep -o -P "^\s*?#.*?$" <<< "$current_setting_line") ]]; then # Check for disabled lines
          if [[ -z $(sed -n -E '\^\['"$current_section"'\]|\b'"$current_section"':$^,\^\s*?'"$(sed -E 's/^[ \t]*//;' <<< "$escaped_setting_line")"'^{ \^\['"$current_section"'\]|\b'"$current_section"':$^! { \^\s*?'"$(sed -E 's/^[ \t]*//' <<< "$escaped_setting_line")"'^ p } }' "$modified_file") ]]; then # If disabled line is not disabled in new file...
          action="disable_setting"
          echo $action"^"$current_section"^"$(sed -n -E 's^\s*?#(.*?)$^\1^p' <<< $(sed -E 's/^[ \t]*//' <<< "$current_setting_line")) >> "$patch_file"
          fi
        elif [[ ! -z $(sed -n -E '\^\['"$current_section"'\]|\b'"$current_section"':$^,\^\s*?#'"$(sed -E 's/^[ \t]*//' <<< "$escaped_setting_line")"'^{ \^\['"$current_section"'\]|\b'"$current_section"':$^! { \^\s*?#'"$(sed -E 's/^[ \t]*//;' <<< "$escaped_setting_line")"'^ p } }' "$modified_file") ]]; then # Check if line is disabled in new file
          action="enable_setting"
          echo $action"^"$current_section"^"$current_setting_line >> "$patch_file"
        else # Look for setting value differences
          current_setting_name=$(get_setting_name "$escaped_setting_line" "$system")
          if [[ (-z $(sed -n -E '\^\['"$current_section"'\]|\b'"$current_section"':$^,\^\b'"$current_setting_name"'\s*?[:=]^{ \^\['"$current_section"'\]|\b'"$current_section"':$^! { \^\b'"$(sed -E 's/^[ \t]*//;' <<< "$escaped_setting_line")"'$^ p } }' "$modified_file")) ]]; then # If the same setting line is not found in the same section of the modified file...
            if [[ ! -z $(sed -n -E '\^\['"$current_section"'\]|\b'"$current_section"':$^,\^\b'"$current_setting_name"'\s*?[:=]^{ \^\['"$current_section"'\]|\b'"$current_section"':$^! { \^\b'"$current_setting_name"'\s*?[:=]^ p } }' "$modified_file") ]]; then # But the setting exists in that section, only with a different value...
              new_setting_value=$(get_setting_value "$2" "$current_setting_name" "$system" $current_section)
              action="change"
              echo $action"^"$current_section"^"$(sed -e 's%\\\\%\\%g' <<< "$current_setting_name")"^"$new_setting_value"^"$system >> "$patch_file"
            fi
          fi
        fi
      elif [[ -z "$current_section" ]]; then # If line is not in a section...
        if [[ ! -z $(grep -o -P "^\s*?#.*?$" <<< "$current_setting_line") ]]; then # Check for disabled lines
          if [[ -z $(grep -o -P "^\s*?$current_setting_line$" "$modified_file") ]]; then # If disabled line is not disabled in new file...
            action="disable_setting"
            echo $action"^"$current_section"^"$(sed -n -E 's^\s*?#(.*?)$^\1^p' <<< "$current_setting_line") >> "$patch_file"
          fi
        elif [[ ! -z $(sed -n -E '\^\s*?#'"$(sed -E 's/^[ \t]*//' <<< "$escaped_setting_line")"'$^p' "$modified_file") ]]; then # Check if line is disabled in new file
            action="enable_setting"
            echo $action"^"$current_section"^"$current_setting_line >> "$patch_file"
        else # Look for setting value differences
          if [[ (-z $(sed -n -E '\^\s*?\b'"$(sed -E 's/^[ \t]*//' <<< "$escaped_setting_line")"'$^p' "$modified_file")) ]]; then # If the same setting line is not found in the modified file...
            current_setting_name=$(get_setting_name "$escaped_setting_line" "$system")
            if [[ ! -z $(sed -n -E '\^\s*?\b'"$current_setting_name"'\s*?[:=]^p' "$modified_file") ]]; then # But the setting exists, only with a different value...
              new_setting_value=$(get_setting_value $2 "$current_setting_name" "$system")
              action="change"
              echo $action"^"$current_section"^"$(sed -e 's%\\\\%\\%g' <<< "$current_setting_name")"^"$new_setting_value"^"$system >> "$patch_file"
            fi
          fi
        fi
      fi
    fi
  done < "$original_file"

    # Reset the variables for reuse
    action=""
    current_section=""
    current_setting_name=""
    current_setting_value=""

  while read -r current_setting_line; # Look for new lines (from dynamically generated config files) in modified file compared to original
  do

    printf -v escaped_setting_line '%q' "$current_setting_line" # Take care of special characters before they mess with future commands

    if [[ (! -z $current_setting_line) && (! $current_setting_line == "#!/bin/bash") && (! $current_setting_line == "[]") ]]; then # Ignore empty lines, empty arrays or Bash start lines
      if [[ ! -z $(grep -o -P "^\[.+?\]$" <<< "$current_setting_line") || ! -z $(grep -o -P "^\b.+?:$" <<< "$current_setting_line") ]]; then # Capture section header lines
      if [[ $current_setting_line =~ ^\[.+\] ]]; then # If normal section line
        action="section"
        current_section=$(sed 's^[][]^^g' <<< $current_setting_line) # Remove brackets from section name
      elif [[ ! -z $(grep -o -P "^\b.+?:$" <<< "$current_setting_line") ]]; then # If RPCS3 section name
        action="section"
        current_section=$(sed 's^:$^^' <<< $current_setting_line) # Remove colon from section name
      fi
      elif [[ (! -z $current_section) ]]; then
        current_setting_name=$(get_setting_name "$escaped_setting_line" "$4")
        if [[ -z $(sed -n -E '\^\['"$current_section"'\]|\b'"$current_section"':$^,\^\b'"$current_setting_name"'.*^{ \^\['"$current_section"'\]|\b'"$current_section"':$^! { \^\b'"$current_setting_name"'^p } }' $1 ) ]]; then # If setting name is not found in this section of the original file...
          action="add_setting_line" # TODO: This should include the previous line, so that new lines can be inserted in the correct place rather than at the end.
          echo $action"^"$current_section"^"$current_setting_line"^^"$4 >> $3
        fi
      elif [[ (-z $current_section) ]]; then
        current_setting_name=$(get_setting_name "$escaped_setting_line" "$4")
        if [[ -z $(sed -n -E '\^\s*?\b'"$current_setting_name"'\s*?[:=]^p' $1) ]]; then # If setting name is not found in the original file...
          action="add_setting_line" # TODO: This should include the previous line, so that new lines can be inserted in the correct place rather than at the end.
          echo $action"^"$current_section"^"$current_setting_line"^^"$4 >> $3
        fi
      fi
    fi
  done < "$modified_file"
}

deploy_single_patch() {

# This function will take an "original" file and a patch file and generate a ready to use modified file
# USAGE: deploy_single_patch $original_file $patch_file $output_file

cp -fv "$1" "$3" # Create a copy of the original file to be patched

while IFS="^" read -r action current_section setting_name setting_value system_name
do

  case $action in

	"disable_file" )
    eval disable_file "$setting_name"
	;;

	"enable_file" )
    eval enable_file "$setting_name"
	;;

	"add_setting_line" )
    add_setting_line "$3" "$setting_name" "$system_name" "$current_section"
	;;

	"disable_setting" )
    disable_setting "$3" "$setting_name" "$system_name" "$current_section"
	;;

	"enable_setting" )
    enable_setting "$3" "$setting_name" "$system_name" "$current_section"
	;;

	"change" )
    if [[ "$setting_value" = \$* ]]; then # If patch setting value is a reference to an internal variable name
      eval setting_value="$setting_value"
    fi
    set_setting_value "$3" "$setting_name" "$setting_value" "$system_name" "$current_section"
  ;;

  *"#"* )
	  # Comment line in patch file
	;;

	* )
	  echo "Config line malformed: $action"
	;;

  esac
done < "$2"
}

deploy_multi_patch() {

# This function will take a single "batch" patch file and run all patches listed in it, across multiple config files
# USAGE: deploy_multi_patch $patch_file
# Patch file format should be as follows, with optional entries in (). Optional settings can be left empty, but must still have ^ dividers:
# $action^($current_section)^$setting_name^$setting_value^$system_name^($config file)

while IFS="^" read -r action current_section setting_name setting_value system_name config_file
do
  case $action in

	"disable_file" )
    if [[ "$config_file" = \$* ]]; then # If patch setting value is a reference to an internal variable name
      eval config_file="$config_file"
    fi
    disable_file "$config_file"
	;;

	"enable_file" )
    if [[ "$config_file" = \$* ]]; then # If patch setting value is a reference to an internal variable name
      eval config_file="$config_file"
    fi
    enable_file "$config_file"
	;;

	"add_setting_line" )
    if [[ "$config_file" = \$* ]]; then # If patch setting value is a reference to an internal variable name
      eval config_file="$config_file"
    fi
    add_setting_line "$config_file" "$setting_name" "$system_name" "$current_section"
	;;

	"disable_setting" )
    if [[ "$config_file" = \$* ]]; then # If patch setting value is a reference to an internal variable name
      eval config_file="$config_file"
    fi
    disable_setting "$config_file" "$setting_name" "$system_name" "$current_section"
	;;

	"enable_setting" )
    if [[ "$config_file" = \$* ]]; then # If patch setting value is a reference to an internal variable name
      eval config_file="$config_file"
    fi
    enable_setting "$config_file" "$setting_name" "$system_name" "$current_section"
	;;

	"change" )
    if [[ "$setting_value" = \$* ]]; then # If patch setting value is a reference to an internal variable name
      eval setting_value="$setting_value"
    fi
    set_setting_value "$config_file" "$setting_name" "$setting_value" "$system_name" "$current_section"
  ;;

  *"#"* )
	  # Comment line in patch file
	;;

	* )
	  echo "Config line malformed: $action"
	;;

  esac
done < "$1"
}