#!/usr/bin/env bash

# Dependencies
# * bash (includes bash extentions that are not in posix shell eg [[ ]]
# * sqlite3
# * sed
# * awk
# * tr
# * git
# * yq (https://github.com/kislyuk/yq)
# * fzf (https://github.com/junegunn/fzf)
# * rg (https://github.com/BurntSushi/ripgrep)
# * bat (https://github.com/sharkdp/bat)



# Colour definitions
RED='\033[1;31m'
GREEN='\033[1;32m'
YELLOW='\033[1;33m'
WHITE='\033[1;37m'
NC='\033[0m'

# Provide a variable with the location of this script.
#scriptPath="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"

# Source files
# ##################################################

source "inc/init"
source "inc/tag-management"
source "inc/file-management"
source "inc/yaml"

# Utility functions
# ##################################################

die(){
	necho -e "${RED}$*${NC}" >&2
	exit 1
}

# Normal echo
# Echo if quiet is 0
necho(){
	if [ "$quiet" -eq 0 ]; then
		echo "$@"
	fi
}

# verbose echo
# Echo if verbose is 1
vecho(){
	if [ "$verbose" -eq 1 ]; then
		echo "$@"
	fi
}

# Exits after any cleanup that may be needed
safeExit(){
	# TODO: Add cleanup
	exit 0
}


isInt() {
	[ "$1" -eq "$1" ] 2> /dev/null
	return "$?"
}

# Escapes ' and \ characters
safeSQL(){
	echo "$1" |
		sed 's/\\/\\\\/g' |
		sed "s/'/\\\'/g"
}


# Set Flags
# -----------------------------------
# Flags which can be overridden by user input.
# Default values are below
# -----------------------------------
quiet=0
verbose=0
debug=0
dogit=1
args=()
dataDir="${XDG_DATA_HOME:=$HOME/.local/share}/kb/"
sqliteFile=""
editor="${EDITOR:=vim}"
if type -p bat > /dev/null 2>&1; then
	pager="bat"
else
	pager="${PAGER:=cat}"
fi

# Check for Dependencies
# -----------------------------------
# Arrays containing package dependencies needed to execute this script.
# The script will fail if dependencies are not installed.
# -----------------------------------
checkDependencies(){
	local dependencies=(
		"sqlite3"
		"rg"
		"fzf"
		"sed"
		"awk"
		"tr"
		"git"
		"yq"
		"bat"
	)
	local ret=0
	for program in "${dependencies[@]}"; do
		if ! type "$program" &>/dev/null; then
			necho -e "${RED}$program is not installed${NC}"
			ret=1
			case "$program" in
				"rg")
					necho -e "\t${YELLOW}This provides effecient searching${NC}"
					;;
				"fzf")
					necho -e "\t${YELLOW}This provides fuzzy searching${NC}"
					;;

			esac
		fi
	done
	return $ret
}

# This will create a fresh database based on the files in the folder
makedb(){
	[ -f "$sqliteFile" ] && die "sqlite file already exists\ndelete it first if you want to"
	echo "Still need to implement this"
}


# Makes file names safe
escapeFilename(){
	vecho "escapeFilename $*"
	echo "$1" |
		tr ' ' '_' | # replace spaces with underscores
		tr -d '/' # Delete slashes
}

findFileId(){
	local filename
	filename="$(findFile "$1")"
	[ ! -e "$filename" ] && exit 1
	echo "SELECT id FROM items WHERE filename = '$(safeSQL "$filename")'" |
		sqlite3 "${sqliteFile}"

}

findFile(){
	vecho "findFile $*"
	cd "$dataDir" || return
	local filename

	if [ "$#" -eq 1 ] && isInt "$1"; then
		filename="$(echo "SELECT filename
		FROM items WHERE id = '$(safeSQL "$1")'" |
			sqlite3 "${sqliteFile}")"
	fi

	[ -z "$filename" ] && filename="$(escapeFilename "$*")"
	if [ -e "$filename" ]; then
		# If the file exists, return it
		echo "$filename"
		exit 0
	else
		# If it exists with .md at the end, assume that was meant
		# otherwise die
		if [ -e "$filename.md" ]; then
			echo "$filename.md"
			exit 0
		else
			die "No such file or ID $filename"
			exit 1
		fi
	fi
}

fileInDB(){
	local ids
	ids="$(echo "SELECT id FROM items WHERE filename = '$(safeSQL "$1")'" |
			sqlite3 "${sqliteFile}")"
	[ -n "$ids" ] && return 0
	return 1
}

externalgit(){
	cd "$dataDir" || return
	git "$@"
}

# This function will add and commit a file after it has been edited
# If 2 arguments are given, it assumes a rename has taken place.
# The first should be the old file (like mv)
gitChange(){
	cd "$dataDir" || return
	local filename="$1"
	local newFilename="$2"
	if [ "$dogit" -gt 0 ]; then
		if [ -f "$filename" ]; then
			if ! git diff --exit-code "$filename" > /dev/null 2>&1; then
				# Changes
				git add "$filename"
				git commit -m "KB auto-commit: Updated: $filename"
			elif ! git ls-files --error-unmatch "$filename" > /dev/null 2>&1; then
				# New file
				git add "$filename"
				git commit -m "KB auto-commit: New: $filename"
			fi
		else
			# If the file name doesn't exist, we have probably moved it
			if [ -n "$newFilename" ] && [ -f "$newFilename" ]; then
				git add "$filename" "$newFilename"
				git commit -m "KB auto-commit: move: $filename -> $newFilename"
			else
				# if we get here, the file has been deleted
				git add "$filename"
				git commit -m "KB auto-commit: delete: $filename"
			fi
		fi
	fi
}

listEntries(){
	vecho "listEntries $*"
	cd "$dataDir" || return
	local header="--header"
	[ "$1" = "--noheader" ] && header=""
	echo "SELECT items.id,items.filename,items.title,items.type,
	GROUP_CONCAT(tags.name,',') tags
	FROM items LEFT JOIN links ON items.id = links.itemID
	LEFT JOIN tags ON links.tagID = tags.id
	GROUP BY items.id;" |
		sqlite3 --column $header "${sqliteFile}"
}

fuzzySelect(){
	cd "$dataDir" || return
	local id
	local query
	local operation
	local output
	local header="$(echo -e "Type to filter

${YELLOW}ctrl+n $WHITE create new      ${YELLOW}ctrl+v $WHITE view selected
${YELLOW}ctrl+e $WHITE edit selected   ${YELLOW}ctrl+d $WHITE delete selected
")"
	export -f fzfPreview
	export dataDir
	output="$(listEntries |
		fzf --header="$header" --header-lines=2 --print-query \
		--delimiter="  +" --with-nth=3,5 --height=100% \
		--expect="ctrl-n,ctrl-o,ctrl-e,ctrl-d"  \
		--preview='bash -c "fzfPreview {}"')"

	query="$(echo "$output" | sed -n '1p')"
	operation="$(echo "$output" | sed -n '2p')"
	id="$(echo "$output" | sed -n '3p' | cut -d' ' -f1)"

	case "$operation" in
		'ctrl-n') newFile "$query" ;;
		'ctrl-o') viewFile "$id" ;;
		'ctrl-e') editFile "$id" ;;
		'ctrl-d') deleteFile "$id" ;;
		'')
			case "$1" in
				edit) editFile "$id" ;;
				view) viewFile "$id" ;;
				*) viewFile "$id" ;;
			esac
			;;
		*) die "unknown operation '$operation'" ;;
	esac

}

fzfPreview(){
	cd "$dataDir" || return

	local id
	local filename
	local title
	local type
	local tags

	id="$(echo "$1" | awk -F '  +' '{print $1}')"
	filename="$(echo "$1" | awk -F '  +' '{print $2}')"
	title="$(echo "$1" | awk -F '  +' '{print $3}')"
	type="$(echo "$1" | awk -F '  +' '{print $4}')"
	tags="$(echo "$1" | awk -F '  +' '{print $5}')"

	if [ "$type" = "normal" ]; then
		bat --color=always --style=full "$filename"
	fi
}

doDeepSearch(){
	cd "$dataDir" || return
	local query="$1"
	echo "$query"
	rg --column --line-number --no-heading --color=always --smart-case "$query"
}

doDeepPreview(){
	cd "$dataDir" || return
	local file
	local line
	file="$(echo "$1" | cut -d ':' -f 1)"
	line="$(echo "$1" | cut -d ':' -f 2)"
	bat --color=always --style=full -H "$line" "$file"
}

deepSearch(){
	type -p rg > /dev/null || die "You need rg installed for deep search"
	export -f doDeepSearch
	export -f doDeepPreview
	export dataDir
	echo "" | fzf --ansi \
		--bind 'change:reload:bash -c "doDeepSearch {q} || true"' \
		--preview 'bash -c "doDeepPreview {} || true"'
}

mainScript() {
	############## Begin Script Here ###################
	####################################################
	if [ "${args[0]}" != "init" ]; then
		cd "$dataDir" || return
		# Check to see if datadir is a git repo
		if ! git rev-parse 2> /dev/null; then
			# If not, ensure we don't run git commands
			dogit=0
		fi
	fi
	case "${args[0]}" in
		init) initKnowledgeBase; safeExit ;;
		makedb) makedb; safeExit ;;
		new) newFile "${args[@]:1}"; safeExit ;;
		edit) editFile "${args[@]:1}"; safeExit ;;
		list) listEntries "${args[@]:1}"; safeExit ;;
		list-tags) listTags "${args[@]:1}"; safeExit ;; 
		view) viewFile "${args[@]:1}"; safeExit ;;
		fuzzy) fuzzySelect "${args[@]:1}"; safeExit ;;
		update) updateFileChange "${args[@]:1}"; safeExit ;;
		deepsearch) deepSearch "${args[@]:1}"; safeExit ;;
		del|delete) deleteFile "${args[@]:1}"; safeExit ;;
		git) externalgit "${args[@]:1}"; safeExit ;;
		*) usage >&2; safeExit ;;
	esac


	####################################################
	############### End Script Here ####################
}

############## Begin Options and Usage ###################


# Print usage
usage() {
	echo -n "kb [OPTIONS]... COMMAND

	Knowledge Base Management

	This tool helps manage my personal knowledge base

	Options:
	-q, --quiet             Quiet (no output)
	-v, --verbose           Output more information. (Items echoed to 'verbose')
	-d, --debug             Runs script in BASH debug mode (set -x)
	-h, --help              Display this help and exit
	--data <directory>      The knowledgebase data dir
	--sqlite <file>         The sqlite file (default to <data>/knowledgebase.sqlite3
	--editor <editor>       The editor to use (default $EDITOR or vim)
	--pager <editor>        The pager to use (default bat or $PAGER or cat)
	--nogit                 Don't run git commands
	--version               Output version information and exit

	Commands:
	init                    Initialise a new knowledgebase
	new [options] [title]   Create new entry
		--filetype <type>   Type of file ( default md)
	edit [title]            Edit a file
	list                    List all files
		--noheader          Don't include the header
	list-tags               Lists tags with the number of times its used
		--noheader          Don't include the header
	update <file> [<file>]  Updates the database and git repo of a changed file
	                        If 2 files are given, it assumes a move
	view                    View a file
	fuzzy [command]         Fuzzy select a file
		command is what to do with the selected file
		edit or view
	git [options]           Run arbitary git commands on the kb repository
	del [title]             Delete a file
"
}

# Iterate over options breaking -ab into -a -b when needed and --foo=bar into
# --foo bar
optstring=h
unset options
while (($#)); do
	case $1 in
		# If option is of type -ab
		-[!-]?*)
		# Loop over each character starting with the second
		for ((i=1; i < ${#1}; i++)); do
			c=${1:i:1}

			# Add current char to options
			options+=("-$c")

			# If option takes a required argument, and it's not the last char make
			# the rest of the string its argument
			if [[ $optstring = *"$c:"* && ${1:i+1} ]]; then
				options+=("${1:i+1}")
				break
			fi
		done
		;;

		# If option is of type --foo=bar
		--?*=*) options+=("${1%%=*}" "${1#*=}") ;;
		# add --endopts for --
		--) options+=(--endopts) ;;
		# Otherwise, nothing special
		*) options+=("$1") ;;
	esac
	shift
done
set -- "${options[@]}"
unset options

# Print help if no arguments were passed.
# Uncomment to force arguments when invoking the script
[[ $# -eq 0 ]] && set -- "--help"

# Read the options and set stuff
while [[ $1 = -?* ]]; do
	case $1 in
		-h|--help) usage >&2; safeExit ;;
		-v|--verbose) verbose=1 ;;
		-q|--quiet) quiet=1 ;;
		-d|--debug) debug=1;;
		--data) dataDir="$2"; shift ;;
		--sqlite) sqliteFile="$2"; shift ;;
		--editor) editor="$2"; shift ;;
		--pager) pager="$2"; shift ;;
		--nogit) dogit=0 ;;
		--) shift; break ;;
		*) die "invalid option: '$1'." ;;
	esac
	shift
done

# If the sqlite file hasn't been specified on the command line, make it a file
# called knowledgebase.sqlite3 in the dataDir
[ -z "$sqliteFile" ] && sqliteFile="${dataDir}/knowledgebase.sqlite3"

# Store the remaining part as arguments.
args+=("$@")

############## End Options and Usage ###################




# ############# ############# #############
# ##       TIME TO RUN THE SCRIPT        ##
# ##                                     ##
# ## You shouldn't need to edit anything ##
# ## beneath this line                   ##
# ##                                     ##
# ############# ############# #############

# Exit on error. Append '||true' when you run the script if you expect an error.
set -o errexit

# Run in debug mode, if set
if [ "${debug}" == "1" ]; then
	set -x
fi

# Bash will remember & return the highest exitcode in a chain of pipes.
# This way you can catch the error in case mysqldump fails in `mysqldump |gzip`, for example.
set -o pipefail

# Invoke the checkDependencies function to test for Bash packages
checkDependencies


# Run your script
mainScript

safeExit # Exit cleanly

[ -n "$KB_DIR" ] && dataDir="$KB_DIR" ||
	dataDir="${XDG_DATA_HOME:=$HOME/.local/share}/kb/"

mkdir -p "$dataDir"