//! helpコマンドの実装
//!
//! 各コマンドの詳細なヘルプテキストを表示します。

use crate::cli::HelpArgs;
use crate::error::Result;

/// ヘルプテキスト定義モジュール
mod help_text {
    pub const GLOBAL: &str = r#"
gwm - Git Worktree Manager

A CLI tool for managing Git worktrees with an interactive TUI.

USAGE:
    gwm [COMMAND]

COMMANDS:
    list (ls)       List all worktrees
    add             Add a new worktree
    remove (rm)     Remove worktree(s)
    go              Navigate to a worktree
    clean           Clean up merged/deleted worktrees
    sync            Sync main branch worktrees
    help            Show this help message

EXAMPLES:
    gwm                     Show welcome message
    gwm list                Show worktree list
    gwm add                 Create new worktree (interactive)
    gwm add -r              Create from remote branch
    gwm remove              Remove worktrees (multi-select)
    gwm go feature          Navigate to worktree matching "feature"
    gwm clean -n            Show cleanable worktrees (dry-run)

For more information about a command, run:
    gwm help <COMMAND>
    gwm <COMMAND> --help

CONFIGURATION:
    Config file: ~/.config/gwm/config.toml

    Example config:
        worktree_base_path = "~/git-worktrees"
        main_branches = ["main", "master", "develop"]
        clean_branch = "ask"  # auto | ask | never

        [copy_ignored_files]
        enabled = true
        patterns = [".env", ".env.*"]

        [hooks.post_create]
        enabled = true
        commands = ["npm install"]
"#;

    pub const LIST: &str = r#"
gwm list - List all worktrees

USAGE:
    gwm list [OPTIONS]
    gwm ls [OPTIONS]

OPTIONS:
        --compact            Use compact format (legacy layout)
        --format <FORMAT>    Output format: table (default), json, names

DESCRIPTION:
    Display a table of all Git worktrees with their status, branch, path,
    and HEAD commit hash.

STATUS INDICATORS:
    [*] ACTIVE  - Current working worktree (yellow)
    [M] MAIN    - Main branch worktree (cyan)
    [-] OTHER   - Other worktrees (white)

EXAMPLES:
    gwm list                 Show all worktrees
    gwm ls                   Same as above (alias)
    gwm list --compact       Use compact format
    gwm list --format json   Output as JSON (for scripting)
"#;

    pub const ADD: &str = r#"
gwm add - Add a new worktree

USAGE:
    gwm add [OPTIONS] [BRANCH_NAME]

ARGUMENTS:
    [BRANCH_NAME]    Name for the new branch (optional)

OPTIONS:
    -r, --remote           Select from remote branches
        --from <BRANCH>    Base branch for new worktree (default: main)
    -o, --open <EDITOR>    Open in editor after creation (code, cursor, zed)
        --no-cd            Show success message instead of path output
        --skip-hooks       Skip post_create hook execution

DESCRIPTION:
    Create a new worktree. Without arguments, opens an interactive text input
    for entering a new branch name. With -r flag, shows a list of remote
    branches to select from.

    The worktree is created at:
        {worktree_base_path}/{repo_name}/{branch_name}

    Branch names are sanitized: feature/auth → feature-auth

EXAMPLES:
    gwm add                       Interactive new branch input
    gwm add feature/auth          Create worktree for "feature/auth"
    gwm add -r                    Select from remote branches
    gwm add --from develop        Branch from "develop" instead of main
    gwm add feature -o code       Create and open in VS Code
    gwm add feature -o cursor     Create and open in Cursor
    gwm add feature --skip-hooks  Create without running hooks
"#;

    pub const REMOVE: &str = r#"
gwm remove - Remove worktree(s)

USAGE:
    gwm remove [OPTIONS] [QUERY]
    gwm rm [OPTIONS] [QUERY]

ARGUMENTS:
    [QUERY]    Filter worktrees by name (optional)

OPTIONS:
    -f, --force              Force removal without confirmation
        --clean-branch <MODE>    Local branch cleanup mode
                             Values: auto, ask, never (default: config value)

DESCRIPTION:
    Remove one or more worktrees using a multi-select interface.
    Main worktrees cannot be selected for removal.

    clean-branch modes:
        auto  - Automatically delete merged branches, force delete unmerged
        ask   - Prompt before deleting each branch
        never - Keep local branches (default)

EXAMPLES:
    gwm remove              Multi-select interface
    gwm rm feature          Filter by "feature"
    gwm remove -f           Force remove without confirmation
    gwm remove --clean-branch auto  Auto-delete local branches
"#;

    pub const GO: &str = r#"
gwm go - Navigate to a worktree

USAGE:
    gwm go [OPTIONS] [QUERY]

ARGUMENTS:
    [QUERY]    Filter worktrees by name (optional)

OPTIONS:
    -o, --open <EDITOR>    Open in editor (code, cursor, zed)
        --no-cd            Show success message instead of path output

DESCRIPTION:
    Navigate to a worktree by outputting its path. Designed to work with
    a shell function for directory navigation.

    Without options, prints the worktree path to stdout.
    With --open, opens the worktree in the specified editor.

EXAMPLES:
    gwm go                  Interactive selection
    gwm go feature          Select matching "feature"
    gwm go main -o code     Open main worktree in VS Code
    gwm go main -o cursor   Open main worktree in Cursor
"#;

    pub const CLEAN: &str = r#"
gwm clean - Clean up merged/deleted worktrees

USAGE:
    gwm clean [OPTIONS]

OPTIONS:
    -n, --dry-run    Show what would be deleted without deleting
        --force      Skip confirmation prompt

DESCRIPTION:
    Safely remove worktrees that are no longer needed. A worktree is
    considered cleanable if ALL of the following conditions are met:

    1. Remote branch has been deleted, OR
    2. Local branch is merged into a main branch

    AND:
    3. No uncommitted changes
    4. No unpushed commits

    Main and active worktrees are never cleaned.

EXAMPLES:
    gwm clean              Show confirmation before cleaning
    gwm clean -n           Dry run: show candidates only
    gwm clean --force      Clean without confirmation (for CI/CD)
"#;

    pub const SYNC: &str = r#"
gwm sync - Sync main branch worktrees

USAGE:
    gwm sync
    gwm pull-main  (legacy alias)

DESCRIPTION:
    Run 'git pull' in all worktrees that track main branches.
    Main branches are defined in the config file.

    Default main branches: main, master, develop

EXAMPLES:
    gwm sync               Sync all main branch worktrees
"#;

    pub const HELP: &str = r#"
gwm help - Show help information

USAGE:
    gwm help [COMMAND]

ARGUMENTS:
    [COMMAND]    The command to show help for (optional)

DESCRIPTION:
    Display detailed help for gwm or a specific command.
    Without arguments, shows the general help message.

EXAMPLES:
    gwm help         Show general help
    gwm help add     Show help for 'add' command
    gwm help remove  Show help for 'remove' command
"#;
}

/// helpコマンドを実行
pub fn run_help(args: HelpArgs) -> Result<()> {
    let text = match args.command.as_deref() {
        None => help_text::GLOBAL,
        Some("list") | Some("ls") => help_text::LIST,
        Some("add") => help_text::ADD,
        Some("remove") | Some("rm") => help_text::REMOVE,
        Some("go") => help_text::GO,
        Some("clean") => help_text::CLEAN,
        Some("sync") | Some("pull-main") => help_text::SYNC,
        Some("help") => help_text::HELP,
        Some(cmd) => {
            eprintln!("Unknown command: {}", cmd);
            eprintln!("Run 'gwm help' for available commands.");
            return Ok(());
        }
    };

    println!("{}", text.trim());
    Ok(())
}

#[cfg(test)]
mod tests {
    use super::*;

    /// テーブル駆動テスト: 各コマンドに対してrun_helpが正常に実行されることを確認
    #[test]
    fn test_run_help_for_all_commands() {
        // (テスト名, コマンド引数)
        let test_cases: &[(&str, Option<&str>)] = &[
            ("global", None),
            ("list", Some("list")),
            ("list_alias_ls", Some("ls")),
            ("add", Some("add")),
            ("remove", Some("remove")),
            ("remove_alias_rm", Some("rm")),
            ("go", Some("go")),
            ("clean", Some("clean")),
            ("sync", Some("sync")),
            ("sync_alias_pull_main", Some("pull-main")),
            ("help", Some("help")),
            ("unknown", Some("unknown")),
        ];

        for (name, command) in test_cases {
            let args = HelpArgs {
                command: command.map(String::from),
            };
            let result = run_help(args);
            assert!(
                result.is_ok(),
                "run_help failed for command '{}': {:?}",
                name,
                result.err()
            );
        }
    }

    /// ヘルプテキスト定数が空でないことを確認
    #[test]
    fn test_help_text_constants_not_empty() {
        let texts: &[(&str, &str)] = &[
            ("GLOBAL", help_text::GLOBAL),
            ("LIST", help_text::LIST),
            ("ADD", help_text::ADD),
            ("REMOVE", help_text::REMOVE),
            ("GO", help_text::GO),
            ("CLEAN", help_text::CLEAN),
            ("SYNC", help_text::SYNC),
            ("HELP", help_text::HELP),
        ];

        for (name, text) in texts {
            assert!(
                !text.trim().is_empty(),
                "help_text::{} should not be empty",
                name
            );
        }
    }
}
