package main

import (
	"fmt"
	"io"
	"strings"
)

var completionShells = []string{"bash", "zsh", "fish"}

func handleVersionCommand(args []string, output io.Writer) (bool, error) {
	if len(args) == 0 || args[0] != "--version" {
		return false, nil
	}
	if len(args) != 1 {
		return true, fmt.Errorf("usage: diple --version")
	}
	_, err := fmt.Fprintf(output, "diple %s\n", dipleVersion)
	return true, err
}

func handleCompletionCommand(args []string, output io.Writer) (bool, error) {
	if len(args) == 0 || args[0] != "completion" {
		return false, nil
	}
	if len(args) == 2 && (args[1] == "-h" || args[1] == "--help") {
		_, err := fmt.Fprintln(output, completionHelp)
		return true, err
	}
	if len(args) != 2 {
		return true, fmt.Errorf("usage: diple completion <bash|zsh|fish>")
	}
	var script string
	switch args[1] {
	case "bash":
		script = bashCompletion
	case "zsh":
		script = zshCompletion
	case "fish":
		script = fishCompletion
	default:
		return true, fmt.Errorf(
			"unsupported shell %q; choose %s",
			args[1], strings.Join(completionShells, ", "),
		)
	}
	_, err := io.WriteString(output, script)
	return true, err
}

const completionHelp = `Generate a shell completion script.

Usage:
  diple completion <shell>

Available shells:
  bash
  zsh
  fish

Run 'diple completion <shell>' and source or install the generated script.
See the README for shell-specific installation paths.`

func writeCLIHelp(output io.Writer, defaults Config, configPath string) {
	fmt.Fprintf(output, `diple — review and manage GitHub pull requests from the terminal

Usage:
  diple [options]
  diple --version
  diple completion <bash|zsh|fish>
  diple help

Pull-request selection:
  --repo OWNER/REPOSITORY   Limit results to one repository (or use GH_REPO).
  --all[=BOOL]              Include every open PR in --repo. Default: %t.
  --limit NUMBER            Maximum PRs to load, from 1 to 1000. Default: %d.

GitHub and refresh:
  --poll DURATION           Base refresh interval, at least 2s. Default: %s.
  --endpoint URL            GitHub GraphQL endpoint.
                            Default: %s.

Appearance and navigation:
  --theme NAME              dark, light, catppuccin, catppuccin-latte,
                            gruvbox, gruvbox-light, one-dark-pro, github,
                            github-light, high-contrast, no-color, or custom.
                            Default: %s.
  --dashboard-mode MODE     hotkey or intermediate. Default: %s.
  --thread-list-width N     List width in percent, from 20 to 60. Default: %d.
  --fold-resolved[=BOOL]    Start resolved threads folded. Default: %t.
  --compact-reviews[=BOOL]  Aggregate submitted-review history. Default: %t.
  --path-scroll[=BOOL]      Scroll truncated file paths. Default: %t.
  --path-scroll-interval D  Path scroll step interval. Default: %s.
  --editor-mode MODE        vim or standard. Default: %s.

Local state:
  --config FILE             TOML configuration file.
                            Default: %s.
  --cache[=BOOL]            Enable instant cached startup and offline fallback.
                            Default: %t.
  --cache-max-age DURATION  Maximum offline cache age; 0 disables expiry.
                            Default: %s.
  --cache-dir DIRECTORY     Override the operating-system cache directory.

Other:
  -h, --help                Show this help and exit.
  --version                 Show the application version and exit.

Boolean options accept explicit values, for example --cache=false.
Command-line options override TOML settings. GH_REPO is used only when
--repo is absent. DIPLE_CONFIG selects a configuration file; GH_THREADS_CONFIG
is retained as a migration fallback.

Authentication uses GH_TOKEN or GITHUB_TOKEN when set, otherwise the active
credential from 'gh auth login'. Run 'diple completion --help' for completion
installation guidance.
`,
		defaults.ShowAll,
		defaults.Limit,
		defaults.RefreshInterval.Duration,
		defaults.Endpoint,
		defaults.Theme,
		defaults.Display.DashboardMode,
		defaults.Display.ThreadListWidthPercent,
		defaults.Display.FoldResolved,
		defaults.Display.CompactReviews,
		defaults.Paths.Scroll,
		defaults.Paths.ScrollInterval.Duration,
		defaults.Editing.Mode,
		configPath,
		defaults.Cache.Enabled,
		defaults.Cache.MaxAge.Duration,
	)
}

const bashCompletion = `# bash completion for diple
_diple_completion() {
    local current previous
    current="${COMP_WORDS[COMP_CWORD]}"
    previous="${COMP_WORDS[COMP_CWORD-1]}"

    if [[ ${COMP_CWORD} -eq 1 && ${current} != -* ]]; then
        COMPREPLY=($(compgen -W "completion help" -- "${current}"))
        return
    fi
    if [[ ${COMP_WORDS[1]} == completion ]]; then
        COMPREPLY=($(compgen -W "bash zsh fish" -- "${current}"))
        return
    fi
    if [[ ${COMP_WORDS[1]} == help ]]; then
        COMPREPLY=()
        return
    fi

    case "${previous}" in
        --theme)
            COMPREPLY=($(compgen -W "dark light catppuccin catppuccin-mocha catppuccin-latte gruvbox gruvbox-dark gruvbox-light one-dark-pro github github-dark github-light high-contrast no-color custom" -- "${current}"))
            return
            ;;
        --dashboard-mode)
            COMPREPLY=($(compgen -W "hotkey intermediate" -- "${current}"))
            return
            ;;
        --editor-mode)
            COMPREPLY=($(compgen -W "vim standard" -- "${current}"))
            return
            ;;
        --config|--cache-dir)
            COMPREPLY=($(compgen -f -- "${current}"))
            return
            ;;
    esac

    local options="--repo --all --limit --poll --endpoint --theme --dashboard-mode --thread-list-width --fold-resolved --compact-reviews --path-scroll --path-scroll-interval --editor-mode --config --cache --cache-max-age --cache-dir --version --help -h"
    COMPREPLY=($(compgen -W "${options}" -- "${current}"))
}
complete -F _diple_completion diple
`

const zshCompletion = `#compdef diple

_diple() {
  local -a themes
  themes=(dark light catppuccin catppuccin-mocha catppuccin-latte gruvbox gruvbox-dark gruvbox-light one-dark-pro github github-dark github-light high-contrast no-color custom)

  if (( CURRENT == 2 )) && [[ ${PREFIX} != -* ]]; then
    _values 'command' \
      'completion[generate shell completion]' \
      'help[show command-line help]'
    return
  fi
  if [[ ${words[2]} == completion ]]; then
    _values 'shell' bash zsh fish
    return
  fi
  if [[ ${words[2]} == help ]]; then
    return
  fi

  _arguments -s \
    '--repo[limit results to one repository]:owner/repository:' \
    '--all=[include every open PR in the repository]:boolean:(true false)' \
    '--limit[maximum pull requests to load]:number:' \
    '--poll[base GitHub refresh interval]:duration:' \
    '--endpoint[GitHub GraphQL endpoint]:url:' \
    '--theme[UI and syntax color theme]:theme:($themes)' \
    '--dashboard-mode[dashboard navigation mode]:mode:(hotkey intermediate)' \
    '--thread-list-width[thread-list width percentage]:percent:' \
    '--fold-resolved=[start resolved threads folded]:boolean:(true false)' \
    '--compact-reviews=[aggregate submitted reviews]:boolean:(true false)' \
    '--path-scroll=[scroll truncated paths]:boolean:(true false)' \
    '--path-scroll-interval[path scrolling interval]:duration:' \
    '--editor-mode[description editor mode]:mode:(vim standard)' \
    '--config[TOML configuration file]:file:_files' \
    '--cache=[enable local read cache]:boolean:(true false)' \
    '--cache-max-age[maximum offline cache age]:duration:' \
    '--cache-dir[local read-cache directory]:directory:_directories' \
    '--version[show application version]' \
    '(-h --help)'{-h,--help}'[show help]'
}

if (( ! ${+functions[compdef]} )); then
  autoload -Uz compinit
  compinit -D
fi
compdef _diple diple
`

const fishCompletion = `# fish completion for diple
complete -c diple -f
complete -c diple -n '__fish_use_subcommand' -a completion -d 'Generate shell completion'
complete -c diple -n '__fish_use_subcommand' -a help -d 'Show help'
complete -c diple -n '__fish_seen_subcommand_from completion' -a 'bash zsh fish'
complete -c diple -l repo -d 'Limit results to owner/repository'
complete -c diple -l all -d 'Include every open PR in --repo'
complete -c diple -l limit -x -d 'Maximum pull requests to load'
complete -c diple -l poll -x -d 'Base GitHub refresh interval'
complete -c diple -l endpoint -x -d 'GitHub GraphQL endpoint'
complete -c diple -l theme -x -a 'dark light catppuccin catppuccin-mocha catppuccin-latte gruvbox gruvbox-dark gruvbox-light one-dark-pro github github-dark github-light high-contrast no-color custom' -d 'UI and syntax color theme'
complete -c diple -l dashboard-mode -x -a 'hotkey intermediate' -d 'Dashboard navigation mode'
complete -c diple -l thread-list-width -x -d 'Thread-list width percentage'
complete -c diple -l fold-resolved -d 'Start resolved threads folded'
complete -c diple -l compact-reviews -d 'Aggregate submitted reviews'
complete -c diple -l path-scroll -d 'Scroll truncated paths'
complete -c diple -l path-scroll-interval -x -d 'Path scrolling interval'
complete -c diple -l editor-mode -x -a 'vim standard' -d 'Description editor mode'
complete -c diple -l config -r -F -d 'TOML configuration file'
complete -c diple -l cache -d 'Enable local read cache'
complete -c diple -l cache-max-age -x -d 'Maximum offline cache age'
complete -c diple -l cache-dir -r -a '(__fish_complete_directories)' -d 'Local read-cache directory'
complete -c diple -l version -d 'Show application version'
complete -c diple -s h -l help -d 'Show help'
`