From c143dfa503ff8794fa9c732603c29336b7ef7abd Mon Sep 17 00:00:00 2001
From: Silas Kraume <silas.kraume1552@gmail.com>
Date: Fri, 29 Mar 2024 02:26:22 +0100
Subject: [PATCH] implement more

---
 cat_win/util/more.py | 98 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 98 insertions(+)
 create mode 100644 cat_win/util/more.py

diff --git a/cat_win/util/more.py b/cat_win/util/more.py
new file mode 100644
index 00000000..2b1c73ff
--- /dev/null
+++ b/cat_win/util/more.py
@@ -0,0 +1,98 @@
+"""
+more
+"""
+
+from math import ceil
+import os
+import sys
+
+class More:
+    """
+    implements 'more' behaviour
+    """
+    ansi_cleaner = lambda x: x
+    step_length = 0
+
+    @staticmethod
+    def setup(ansi_cleaner = lambda x: x, step_length: int = 0):
+        """
+        setup the configuration
+        
+        Parameters:
+        ansi_cleaner (function):
+            remove_ansi_codes_from_line
+        step_length (int):
+            defines how many lines should be displayed before pausing.
+            a value of 0 is equivalent to the size of the terminal window
+        """
+        More.ansi_cleaner = ansi_cleaner
+        More.step_length = step_length
+
+    def __init__(self, lines: list = None) -> None:
+        self.lines = lines if lines else []
+
+    def add_line(self, line: str) -> None:
+        """
+        add a single line.
+
+        Parameters:
+        line (str):
+            the line to append
+        """
+        self.lines.append(line)
+
+    def add_lines(self, lines: list) -> None:
+        """
+        add multiple lines.
+        
+        Parameters:
+        lines (list):
+            the list of lines to append
+        """
+        self.lines += lines
+
+    def step_through(self) -> None:
+        """
+        step through the lines and wait for user input.
+        """
+        def pause_output(percentage: int) -> str:
+            try:
+                user_input = input(f"-- More ({percentage: >2}%) -- ").upper()
+            except EOFError:
+                user_input = ''
+            if not os.isatty(sys.stdin.fileno()):
+                print() # emulate enter-press on piped input
+            print('\x1b[1F\x1b[2K', end='', flush=True) # clear input() line
+            return user_input
+
+        try:
+            t_width, t_height = os.get_terminal_size()
+            t_width, t_height = max(t_width-1, 1), max(t_height-1, 1)
+        except OSError: # PyPy-Error: "Inappropriate ioctl for device"
+            t_width, t_height = 119, 29
+
+        i_length = len(self.lines)
+        first_chunk, chunk_s = True, 1
+        for nr, line in enumerate(self.lines, start=1):
+            print(line)
+
+            if len(More.ansi_cleaner(line)) > t_width:
+                chunk_s += ceil(len(More.ansi_cleaner(line)) / t_width)-1
+            if chunk_s >= t_height and nr < i_length:
+                user_input = '?'
+                while user_input in ['?', 'H', 'HELP']:
+                    user_input = pause_output(nr*100//i_length)
+                    if user_input in ['?', 'H', 'HELP']:
+                        print('Q QUIT       quit')
+                        print('N NEXT       skip to next file')
+                        continue
+                    if user_input in ['N', 'NEXT']:
+                        return
+                    if user_input in ['\x11', 'Q', 'QUIT']: # '\x11' = ^Q
+                        sys.exit(0)
+                if first_chunk:
+                    first_chunk = False
+                    if More.step_length > 0:
+                        t_height = More.step_length
+                chunk_s = 0
+            chunk_s += 1