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// Copyright 2013-2023 The Cobra Authors
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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//      http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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package cobra
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import (
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	"bytes"
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	"fmt"
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	"io"
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	"os"
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	"strings"
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)
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func genFishComp(buf io.StringWriter, name string, includeDesc bool) {
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	// Variables should not contain a '-' or ':' character
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	nameForVar := name
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	nameForVar = strings.ReplaceAll(nameForVar, "-", "_")
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	nameForVar = strings.ReplaceAll(nameForVar, ":", "_")
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	compCmd := ShellCompRequestCmd
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	if !includeDesc {
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		compCmd = ShellCompNoDescRequestCmd
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	}
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	WriteStringAndCheck(buf, fmt.Sprintf("# fish completion for %-36s -*- shell-script -*-\n", name))
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	WriteStringAndCheck(buf, fmt.Sprintf(`
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function __%[1]s_debug
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    set -l file "$BASH_COMP_DEBUG_FILE"
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    if test -n "$file"
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        echo "$argv" >> $file
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    end
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end
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function __%[1]s_perform_completion
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    __%[1]s_debug "Starting __%[1]s_perform_completion"
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    # Extract all args except the last one
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    set -l args (commandline -opc)
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    # Extract the last arg and escape it in case it is a space
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    set -l lastArg (string escape -- (commandline -ct))
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    __%[1]s_debug "args: $args"
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    __%[1]s_debug "last arg: $lastArg"
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    # Disable ActiveHelp which is not supported for fish shell
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    set -l requestComp "%[10]s=0 $args[1] %[3]s $args[2..-1] $lastArg"
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    __%[1]s_debug "Calling $requestComp"
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    set -l results (eval $requestComp 2> /dev/null)
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    # Some programs may output extra empty lines after the directive.
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    # Let's ignore them or else it will break completion.
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    # Ref: https://github.com/spf13/cobra/issues/1279
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    for line in $results[-1..1]
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        if test (string trim -- $line) = ""
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            # Found an empty line, remove it
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            set results $results[1..-2]
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        else
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            # Found non-empty line, we have our proper output
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            break
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        end
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    end
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    set -l comps $results[1..-2]
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    set -l directiveLine $results[-1]
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    # For Fish, when completing a flag with an = (e.g., <program> -n=<TAB>)
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    # completions must be prefixed with the flag
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    set -l flagPrefix (string match -r -- '-.*=' "$lastArg")
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    __%[1]s_debug "Comps: $comps"
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    __%[1]s_debug "DirectiveLine: $directiveLine"
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    __%[1]s_debug "flagPrefix: $flagPrefix"
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    for comp in $comps
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        printf "%%s%%s\n" "$flagPrefix" "$comp"
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    end
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    printf "%%s\n" "$directiveLine"
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end
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# this function limits calls to __%[1]s_perform_completion, by caching the result behind $__%[1]s_perform_completion_once_result
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function __%[1]s_perform_completion_once
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    __%[1]s_debug "Starting __%[1]s_perform_completion_once"
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    if test -n "$__%[1]s_perform_completion_once_result"
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        __%[1]s_debug "Seems like a valid result already exists, skipping __%[1]s_perform_completion"
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        return 0
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    end
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    set --global __%[1]s_perform_completion_once_result (__%[1]s_perform_completion)
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    if test -z "$__%[1]s_perform_completion_once_result"
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        __%[1]s_debug "No completions, probably due to a failure"
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        return 1
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    end
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    __%[1]s_debug "Performed completions and set __%[1]s_perform_completion_once_result"
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    return 0
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end
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# this function is used to clear the $__%[1]s_perform_completion_once_result variable after completions are run
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function __%[1]s_clear_perform_completion_once_result
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    __%[1]s_debug ""
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    __%[1]s_debug "========= clearing previously set __%[1]s_perform_completion_once_result variable =========="
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    set --erase __%[1]s_perform_completion_once_result
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    __%[1]s_debug "Successfully erased the variable __%[1]s_perform_completion_once_result"
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end
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function __%[1]s_requires_order_preservation
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    __%[1]s_debug ""
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    __%[1]s_debug "========= checking if order preservation is required =========="
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    __%[1]s_perform_completion_once
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    if test -z "$__%[1]s_perform_completion_once_result"
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        __%[1]s_debug "Error determining if order preservation is required"
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        return 1
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    end
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    set -l directive (string sub --start 2 $__%[1]s_perform_completion_once_result[-1])
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    __%[1]s_debug "Directive is: $directive"
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    set -l shellCompDirectiveKeepOrder %[9]d
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    set -l keeporder (math (math --scale 0 $directive / $shellCompDirectiveKeepOrder) %% 2)
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    __%[1]s_debug "Keeporder is: $keeporder"
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    if test $keeporder -ne 0
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        __%[1]s_debug "This does require order preservation"
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        return 0
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    end
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    __%[1]s_debug "This doesn't require order preservation"
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    return 1
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end
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# This function does two things:
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# - Obtain the completions and store them in the global __%[1]s_comp_results
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# - Return false if file completion should be performed
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function __%[1]s_prepare_completions
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    __%[1]s_debug ""
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    __%[1]s_debug "========= starting completion logic =========="
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    # Start fresh
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    set --erase __%[1]s_comp_results
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    __%[1]s_perform_completion_once
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    __%[1]s_debug "Completion results: $__%[1]s_perform_completion_once_result"
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    if test -z "$__%[1]s_perform_completion_once_result"
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        __%[1]s_debug "No completion, probably due to a failure"
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        # Might as well do file completion, in case it helps
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        return 1
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    end
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    set -l directive (string sub --start 2 $__%[1]s_perform_completion_once_result[-1])
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    set --global __%[1]s_comp_results $__%[1]s_perform_completion_once_result[1..-2]
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    __%[1]s_debug "Completions are: $__%[1]s_comp_results"
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    __%[1]s_debug "Directive is: $directive"
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    set -l shellCompDirectiveError %[4]d
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    set -l shellCompDirectiveNoSpace %[5]d
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    set -l shellCompDirectiveNoFileComp %[6]d
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    set -l shellCompDirectiveFilterFileExt %[7]d
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    set -l shellCompDirectiveFilterDirs %[8]d
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    if test -z "$directive"
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        set directive 0
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    end
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    set -l compErr (math (math --scale 0 $directive / $shellCompDirectiveError) %% 2)
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    if test $compErr -eq 1
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        __%[1]s_debug "Received error directive: aborting."
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        # Might as well do file completion, in case it helps
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        return 1
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    end
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    set -l filefilter (math (math --scale 0 $directive / $shellCompDirectiveFilterFileExt) %% 2)
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    set -l dirfilter (math (math --scale 0 $directive / $shellCompDirectiveFilterDirs) %% 2)
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    if test $filefilter -eq 1; or test $dirfilter -eq 1
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        __%[1]s_debug "File extension filtering or directory filtering not supported"
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        # Do full file completion instead
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        return 1
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    end
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    set -l nospace (math (math --scale 0 $directive / $shellCompDirectiveNoSpace) %% 2)
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    set -l nofiles (math (math --scale 0 $directive / $shellCompDirectiveNoFileComp) %% 2)
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    __%[1]s_debug "nospace: $nospace, nofiles: $nofiles"
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    # If we want to prevent a space, or if file completion is NOT disabled,
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    # we need to count the number of valid completions.
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    # To do so, we will filter on prefix as the completions we have received
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    # may not already be filtered so as to allow fish to match on different
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    # criteria than the prefix.
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    if test $nospace -ne 0; or test $nofiles -eq 0
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        set -l prefix (commandline -t | string escape --style=regex)
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        __%[1]s_debug "prefix: $prefix"
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        set -l completions (string match -r -- "^$prefix.*" $__%[1]s_comp_results)
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        set --global __%[1]s_comp_results $completions
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        __%[1]s_debug "Filtered completions are: $__%[1]s_comp_results"
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        # Important not to quote the variable for count to work
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        set -l numComps (count $__%[1]s_comp_results)
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        __%[1]s_debug "numComps: $numComps"
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        if test $numComps -eq 1; and test $nospace -ne 0
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            # We must first split on \t to get rid of the descriptions to be
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            # able to check what the actual completion will be.
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            # We don't need descriptions anyway since there is only a single
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            # real completion which the shell will expand immediately.
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            set -l split (string split --max 1 \t $__%[1]s_comp_results[1])
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            # Fish won't add a space if the completion ends with any
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            # of the following characters: @=/:.,
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            set -l lastChar (string sub -s -1 -- $split)
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            if not string match -r -q "[@=/:.,]" -- "$lastChar"
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                # In other cases, to support the "nospace" directive we trick the shell
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                # by outputting an extra, longer completion.
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                __%[1]s_debug "Adding second completion to perform nospace directive"
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                set --global __%[1]s_comp_results $split[1] $split[1].
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                __%[1]s_debug "Completions are now: $__%[1]s_comp_results"
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            end
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        end
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        if test $numComps -eq 0; and test $nofiles -eq 0
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            # To be consistent with bash and zsh, we only trigger file
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            # completion when there are no other completions
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            __%[1]s_debug "Requesting file completion"
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            return 1
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        end
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    end
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    return 0
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end
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# Since Fish completions are only loaded once the user triggers them, we trigger them ourselves
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# so we can properly delete any completions provided by another script.
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# Only do this if the program can be found, or else fish may print some errors; besides,
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# the existing completions will only be loaded if the program can be found.
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if type -q "%[2]s"
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    # The space after the program name is essential to trigger completion for the program
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    # and not completion of the program name itself.
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    # Also, we use '> /dev/null 2>&1' since '&>' is not supported in older versions of fish.
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    complete --do-complete "%[2]s " > /dev/null 2>&1
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end
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# Remove any pre-existing completions for the program since we will be handling all of them.
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complete -c %[2]s -e
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# this will get called after the two calls below and clear the $__%[1]s_perform_completion_once_result global
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complete -c %[2]s -n '__%[1]s_clear_perform_completion_once_result'
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# The call to __%[1]s_prepare_completions will setup __%[1]s_comp_results
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# which provides the program's completion choices.
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# If this doesn't require order preservation, we don't use the -k flag
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complete -c %[2]s -n 'not __%[1]s_requires_order_preservation && __%[1]s_prepare_completions' -f -a '$__%[1]s_comp_results'
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# otherwise we use the -k flag
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complete -k -c %[2]s -n '__%[1]s_requires_order_preservation && __%[1]s_prepare_completions' -f -a '$__%[1]s_comp_results'
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`, nameForVar, name, compCmd,
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		ShellCompDirectiveError, ShellCompDirectiveNoSpace, ShellCompDirectiveNoFileComp,
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		ShellCompDirectiveFilterFileExt, ShellCompDirectiveFilterDirs, ShellCompDirectiveKeepOrder, activeHelpEnvVar(name)))
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}
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// GenFishCompletion generates fish completion file and writes to the passed writer.
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func (c *Command) GenFishCompletion(w io.Writer, includeDesc bool) error {
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	buf := new(bytes.Buffer)
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	genFishComp(buf, c.Name(), includeDesc)
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	_, err := buf.WriteTo(w)
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	return err
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}
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// GenFishCompletionFile generates fish completion file.
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func (c *Command) GenFishCompletionFile(filename string, includeDesc bool) error {
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	outFile, err := os.Create(filename)
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	if err != nil {
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		return err
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	}
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	defer outFile.Close()
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	return c.GenFishCompletion(outFile, includeDesc)
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}
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