from __future__ import annotations

from pathlib import Path

from plyngent.agent import reset_lineno_tracker
from plyngent.tools.file import edit_lineno, edit_replace, read_file, write_file
from tests.test_tools.helpers import call_sync


def _read_lineno(path: str) -> str:
    """Read file with line numbers so edit_lineno allows the edit."""
    _ = reset_lineno_tracker()
    return call_sync(read_file, path, with_lineno=True)


def test_edit_lineno_replace_middle(workspace: object) -> None:
    del workspace
    _ = call_sync(write_file, "a.txt", "one\ntwo\nthree\nfour\n")
    _ = _read_lineno("a.txt")
    out = call_sync(edit_lineno, "a.txt", 2, 3, "TWO\nTHREE\n")
    assert "replaced lines 2-3" in out
    assert "first: 'two'" in out  # old-content excerpt for self-correction
    assert call_sync(read_file, "a.txt") == "L1-4\none\nTWO\nTHREE\nfour\n"


def test_edit_lineno_read_truncated_marks_only_displayed_lines(workspace: object) -> None:
    """A max_chars-truncated numbered read must not mark the unseen tail."""
    del workspace
    _ = call_sync(write_file, "t.txt", "".join(f"line {i}\n" for i in range(1, 101)))
    # Displayed complete lines are editable...
    _ = reset_lineno_tracker()
    _ = call_sync(read_file, "t.txt", with_lineno=True, max_chars=80)
    out = call_sync(edit_lineno, "t.txt", 5, 5, "FIVE\n")
    assert "replaced lines 5-5" in out
    # ...but the truncated tail (never shown) stays unread.
    _ = reset_lineno_tracker()
    _ = call_sync(read_file, "t.txt", with_lineno=True, max_chars=80)
    out = call_sync(edit_lineno, "t.txt", 90, 90, "X\n")
    assert "not read" in out and "90" in out


def test_edit_lineno_error_shows_read_window(workspace: object) -> None:
    """The unread error names the read window so the model can re-read precisely."""
    del workspace
    _ = call_sync(write_file, "j.txt", "a\nb\nc\nd\n")
    _ = reset_lineno_tracker()
    _ = call_sync(read_file, "j.txt", offset=1, limit=2, with_lineno=True)  # lines 2-3
    out = call_sync(edit_lineno, "j.txt", 1, 1, "X\n")
    assert "not read" in out
    assert "read lines 2-3" in out
    assert "margin" in out
    # Ready to copy: 1-based line 1 is offset 0, and n=4 clamps the limit.
    assert "read_file(path='j.txt', offset=0, limit=4, with_lineno=true)" in out


def test_edit_lineno_error_suggests_the_read_file_call(workspace: object) -> None:
    """Both rejections hand back a ready-to-copy call with a 0-based ``offset``."""
    del workspace
    _ = call_sync(write_file, "s.txt", "".join(f"line {i}\n" for i in range(1, 21)))
    _ = reset_lineno_tracker()
    _ = call_sync(read_file, "s.txt", offset=0, limit=10, with_lineno=True)  # lines 1-10
    # Line 15 was never shown; the hint reads it back with a margin (line 12 → offset 11).
    out = call_sync(edit_lineno, "s.txt", 15, 15, "X\n")
    assert "read_file(path='s.txt', offset=11, limit=7, with_lineno=true)" in out
    # A stale read gets a fresh call for the same range after an external write.
    _ = call_sync(write_file, "s.txt", "changed\n", overwrite=True)
    out = call_sync(edit_lineno, "s.txt", 1, 1, "X\n")
    assert "changed since it was read" in out
    assert "read_file(path='s.txt', offset=0, limit=1, with_lineno=true)" in out


def test_edit_lineno_requires_all_lines_read(workspace: object) -> None:
    del workspace
    _ = call_sync(write_file, "r.txt", "a\nb\nc\nd\ne\n")
    _ = reset_lineno_tracker()
    # Only lines 2-4 are read; editing line 1 or 5 must be rejected.
    _ = call_sync(read_file, "r.txt", offset=1, limit=3, with_lineno=True)
    out = call_sync(edit_lineno, "r.txt", 1, 2, "X\n")
    assert "not read" in out and "1" in out
    out = call_sync(edit_lineno, "r.txt", 4, 5, "Y\n")
    assert "not read" in out and "5" in out
    # Fully read range still edits.
    out = call_sync(edit_lineno, "r.txt", 2, 3, "B\nC\n")
    assert "replaced lines 2-3" in out


def test_edit_lineno_append_to_empty_file(workspace: object) -> None:
    """An empty file has nothing to clobber, so appending needs no read."""
    del workspace
    _ = call_sync(write_file, "empty.txt", "")
    _ = reset_lineno_tracker()
    out = call_sync(edit_lineno, "empty.txt", 1, 1, "first\n")
    assert "appended" in out
    assert call_sync(read_file, "empty.txt") == "L1-1\nfirst\n"


def test_edit_lineno_append_requires_last_line_read(workspace: object) -> None:
    del workspace
    _ = call_sync(write_file, "ap.txt", "a\nb\nc\n")
    _ = reset_lineno_tracker()
    # Only lines 1-2 read; appending after line 3 requires line 3 read.
    _ = call_sync(read_file, "ap.txt", offset=0, limit=2, with_lineno=True)
    out = call_sync(edit_lineno, "ap.txt", 4, 4, "d\n")
    assert "not read" in out and "3" in out
    # Appending needs the last line, so the suggested window ends at n.
    assert "read_file(path='ap.txt', offset=0, limit=3, with_lineno=true)" in out
    # Read the last line, then append succeeds.
    _ = call_sync(read_file, "ap.txt", offset=2, limit=1, with_lineno=True)
    out = call_sync(edit_lineno, "ap.txt", 4, 4, "d\n")
    assert "appended" in out
    assert call_sync(read_file, "ap.txt") == "L1-4\na\nb\nc\nd\n"


def test_edit_lineno_delete_range(workspace: object) -> None:
    del workspace
    _ = call_sync(write_file, "b.txt", "a\nb\nc\n")
    _ = _read_lineno("b.txt")
    out = call_sync(edit_lineno, "b.txt", 2, 2, "")
    assert "replaced" in out
    assert call_sync(read_file, "b.txt") == "L1-2\na\nc\n"


def test_edit_lineno_append(workspace: object) -> None:
    assert isinstance(workspace, Path)
    _ = call_sync(write_file, "c.txt", "only\n")
    _ = _read_lineno("c.txt")
    out = call_sync(edit_lineno, "c.txt", 2, 2, "more\n")
    assert "appended" in out
    assert call_sync(read_file, "c.txt") == "L1-2\nonly\nmore\n"


def test_edit_lineno_invalid(workspace: object) -> None:
    del workspace
    _ = call_sync(write_file, "d.txt", "x\n")
    _ = _read_lineno("d.txt")
    assert "start_line" in call_sync(edit_lineno, "d.txt", 0, 1, "y")
    assert "end_line" in call_sync(edit_lineno, "d.txt", 2, 1, "y")


def test_edit_lineno_rejects_without_prior_lineno_read(workspace: object) -> None:
    del workspace
    _ = call_sync(write_file, "e.txt", "hello\nworld\n")
    _ = reset_lineno_tracker()
    out = call_sync(edit_lineno, "e.txt", 1, 1, "hi\n")
    assert "read" in out and "with_lineno=true" in out


def test_edit_lineno_requires_rerun_after_write(workspace: object) -> None:
    del workspace
    _ = call_sync(write_file, "f.txt", "one\ntwo\nthree\n")
    _ = _read_lineno("f.txt")
    _ = call_sync(write_file, "f.txt", "changed\n", overwrite=True)
    out = call_sync(edit_lineno, "f.txt", 1, 1, "x\n")
    assert "changed" in out and "re-read" in out


def test_edit_lineno_requires_rerun_after_edit_replace(workspace: object) -> None:
    del workspace
    _ = call_sync(write_file, "g.txt", "one\ntwo\nthree\n")
    _ = _read_lineno("g.txt")
    _ = call_sync(edit_replace, "g.txt", "two", "TWO")
    out = call_sync(edit_lineno, "g.txt", 2, 2, "x\n")
    assert "changed" in out and "re-read" in out


def test_edit_lineno_invalidates_after_successful_edit(workspace: object) -> None:
    del workspace
    _ = call_sync(write_file, "h.txt", "a\nb\nc\n")
    _ = _read_lineno("h.txt")
    _ = call_sync(edit_lineno, "h.txt", 2, 2, "B\n")
    # After the edit, line numbers are stale — must re-read before editing again.
    out = call_sync(edit_lineno, "h.txt", 2, 2, "C\n")
    assert "changed" in out and "re-read" in out


def test_edit_lineno_detects_external_change(workspace: object) -> None:
    """A mutation outside the file tools (run_argv, another process) is caught."""
    import os
    import time

    assert isinstance(workspace, Path)
    _ = call_sync(write_file, "i.txt", "one\ntwo\nthree\n")
    _ = _read_lineno("i.txt")
    # Simulate an external/process-tool mutation: rewrite content + new mtime.
    _ = call_sync(write_file, "i.txt", "one\ntwo\nthree\nCHANGED\n", overwrite=True)
    os.utime(workspace / "i.txt", (time.time() + 1, time.time() + 1))
    out = call_sync(edit_lineno, "i.txt", 1, 1, "x\n")
    assert "changed since it was read" in out