/**
 * Git worktree remove — pure validation and command-building functions.
 * No pi SDK dependencies for testability.
 */

import path from "path";

// ─── Type Definitions ──────────────────────────────────────────────

/** Error returned when a worktree operation fails. */
export interface WorktreeRemoveError {
	/** Human-readable error message. */
	message: string;
	/** Suggested fix for the user. */
	suggestion?: string;
}

/** Options for removing a worktree. */
export interface RemoveWorktreeOptions {
	/** Force removal even if the worktree has uncommitted changes. Defaults to false. */
	force?: boolean;
}

// ─── Input Validation ──────────────────────────────────────────────

/**
 * Validate input parameters for removing a worktree.
 *
 * Checks that path is non-empty and well-formed.
 *
 * @param worktreePath - Path of the worktree to remove
 * @returns null if valid, or a WorktreeRemoveError describing the problem
 */
export function validateRemoveWorktreeInput(
	worktreePath: string,
): WorktreeRemoveError | null {
	if (!worktreePath || !worktreePath.trim()) {
		return {
			message: "Path cannot be empty.",
			suggestion: "Provide a valid worktree path (e.g., '../worktrees/feature-x').",
		};
	}

	return null;
}

// ─── Main Repository Check ────────────────────────────────────────

/**
 * Check if the target path is the main repository root.
 *
 * Compares resolved paths to handle trailing slashes and relative paths.
 * Removing the main repo is not allowed — use `git worktree prune` instead.
 *
 * @param targetPath - Path of the worktree to remove
 * @param mainRepoRoot - Root path of the main repository
 * @returns true if target is the main repo (removal should be refused)
 */
export function isMainRepository(targetPath: string, mainRepoRoot: string): boolean {
	return path.resolve(targetPath) === path.resolve(mainRepoRoot);
}

// ─── Uncommitted Changes Check ──────────────────────────────────────

/**
 * Check if the worktree has uncommitted changes based on `git status --porcelain` output.
 *
 * Any non-empty porcelain output indicates changes (staged, unstaged, or untracked).
 *
 * @param statusOutput - Raw stdout from `git status --porcelain` in the target worktree
 * @returns true if there are uncommitted changes
 */
export function hasUncommittedChanges(statusOutput: string): boolean {
	return statusOutput.trim().length > 0;
}

// ─── Command Building ──────────────────────────────────────────────

/**
 * Build the `git worktree remove` command arguments.
 *
 * Uses `--force` flag when force option is true to bypass uncommitted changes check.
 *
 * @param worktreePath - Path of the worktree to remove
 * @param options - Optional removal configuration
 * @returns Array of command arguments (excluding 'git' itself)
 */
export function buildWorktreeRemoveCommand(
	worktreePath: string,
	options?: RemoveWorktreeOptions,
): string[] {
	const args = ["worktree", "remove"];

	if (options?.force) {
		args.push("--force");
	}

	args.push(worktreePath);

	return args;
}