@spec collab_color(String.t() | any()) :: String.t()

Deterministic OKLCH color from a user_id hash for consistent color assignment.

Uses :erlang.phash2/2 to generate a hue value (0-359) from the user_id string, producing the same color for the same user across sessions.

Examples

iex> collab_color("user-1")
"oklch(0.7 0.15 42)"  # deterministic hue from hash

@spec format_mention(String.t()) :: String.t()

Formats an @mention as a display string.

Examples

iex> format_mention("Alice")
"@Alice"

@spec format_relative_time(DateTime.t() | nil) :: String.t()

Formats a DateTime as a relative time string.

Returns human-readable strings like "just now", "2 minutes ago", "Yesterday", "3 days ago", or a formatted date for older timestamps.

Examples

iex> format_relative_time(nil)
""

iex> format_relative_time(~U[2026-03-19 12:00:00Z])
"just now"  # if called within 5 seconds

@spec truncate_preview(String.t() | nil, non_neg_integer()) :: String.t()

Truncates text to max_length characters with ellipsis appended.

Returns the original text if it is shorter than or equal to max_length.

Examples

iex> truncate_preview("Hello world", 5)
"Hello..."

iex> truncate_preview("Hi", 10)
"Hi"

iex> truncate_preview(nil, 10)
""

@spec user_initials(String.t() | nil) :: String.t()

Returns initials from a user name (up to 2 characters).

Splits the name on whitespace, takes the first letter of the first two words, and uppercases them.

Examples

iex> user_initials("Jane Doe")
"JD"

iex> user_initials("alice")
"A"

iex> user_initials(nil)
"?"