Restructure core:terminal for better Windows support

core/terminal/terminal.odin

@@ -1,7 +1,6 @@
 package terminal
 
 import "core:os"
-import "core:strings"
 
 /*
 This describes the range of colors that a terminal is capable of supporting.
@@ -25,80 +24,13 @@ is_terminal :: proc(handle: os.Handle) -> bool {
 	return _is_terminal(handle)
 }
 
-/*
-Get the color depth support for the terminal.
-*/
-@(require_results)
-get_color_depth :: proc() -> Color_Depth {
-	// Reference documentation:
-	//
-	// - [[ https://no-color.org/ ]]
-	// - [[ https://github.com/termstandard/colors ]]
-	// - [[ https://invisible-island.net/ncurses/terminfo.src.html ]]
-
-	// Respect `NO_COLOR` above all.
-	if no_color, ok := os.lookup_env("NO_COLOR"); ok {
-		defer delete(no_color)
-		if no_color != "" {
-			return .None
-		}
-	}
-
-	// `COLORTERM` is non-standard but widespread and unambiguous.
-	if colorterm, ok := os.lookup_env("COLORTERM"); ok {
-		defer delete(colorterm)
-		// These are the only values that are typically advertised that have
-		// anything to do with color depth.
-		if colorterm == "truecolor" || colorterm == "24bit" {
-			return .True_Color
-		}
-	}
-
-	if term, ok := os.lookup_env("TERM"); ok {
-		defer delete(term)
-		if strings.contains(term, "-truecolor") {
-			return .True_Color
-		}
-		if strings.contains(term, "-256color") {
-			return .Eight_Bit
-		}
-		if strings.contains(term, "-16color") {
-			return .Four_Bit
-		}
-
-		// The `terminfo` database, which is stored in binary on *nix
-		// platforms, has an undocumented format that is not guaranteed to be
-		// portable, so beyond this point, we can only make safe assumptions.
-		//
-		// This section should only be necessary for terminals that do not
-		// define any of the previous environment values.
-		//
-		// Only a small sampling of some common values are checked here.
-		switch term {
-		case "ansi":       fallthrough
-		case "konsole":    fallthrough
-		case "putty":      fallthrough
-		case "rxvt":       fallthrough
-		case "rxvt-color": fallthrough
-		case "screen":     fallthrough
-		case "st":         fallthrough
-		case "tmux":       fallthrough
-		case "vte":        fallthrough
-		case "xterm":      fallthrough
-		case "xterm-color":
-			return .Three_Bit
-		}
-	}
-
-	return .None
-}
-
 /*
 This is true if the terminal is accepting any form of colored text output.
 */
 color_enabled: bool
 
-@(init, private)
-init_terminal_status :: proc() {
-	color_enabled = get_color_depth() > .None
-}
+/*
+This value reports the color depth support as reported by the terminal at the
+start of the program.
+*/
+color_depth: Color_Depth