"""Unit: the branch-pin UI on the Sources page (phase 135, task 04).

``TODO.md`` L4: "Need to be able to specify the branch for a git
source." The Sources manager lets the owner see, set, change, and
clear a source's branch (ASSUMPTION B6):

* the ADD form gains the optional ``#git-source-branch`` (maxlength
  200, autocomplete=off, the visible "optional — default: the repo's
  default branch" hint) BETWEEN the URL and Token fields; the submit
  body is ``(url, token, branch) => ({ url, ...(branch ? { branch } :
  {}), ...(token ? { token } : {}) })`` — a BLANK branch OMITS the key
  (NULL = the repo's default branch — the pre-phase-135 clone/pull
  behavior), and 201 clears all three credential-free inputs;
* the per-row EDITOR dialog gains ``#ignore-editor-branch`` (after the
  source line, before the ignore textarea, with the "Leave empty for
  the repo's default branch." hint line) — VISIBLE FOR GIT ROWS ONLY
  (local rows hide label + input + hint and the save body OMITS the
  key — local rows are walked, not cloned; the API's 422 is the
  backstop), opens PREFILLED from the stored value (``s.branch ?? ""``
  — unlike the token, the API reports it, so there IS a field to read
  it from);
* THE TRI-STATE ASYMMETRY: the git row's PATCH body ALWAYS includes
  ``branch`` (the trimmed value — an EMPTY save is the deliberate
  CLEAR leg: NULL = the repo's default branch), unlike the token's
  blank = keep (the token stays the conditional key — untouched);
* every STORED git row with a branch shows a ``branch: <name>`` text
  tag in the source cell (the "hidden on" tag idiom — text +
  background, never color alone: the text IS the signal);
  env-fallback rows (no ``s.id``) and NULL-branch rows show no tag;
  the source cell's title names the branch (hover precision).

The browser behavior itself is E2E-gated by the phase-135 story suite
(``tests/e2e/test_git_source_branch.py``, task 05); like the phase-121
``test_git_source_token.py`` house pattern, this module pins the
source-level contract a silent regression would break.
"""
from __future__ import annotations

import re
from pathlib import Path

from app.schemas import GitSourceIn, GitSourceOut, GitSourcePatchIn, GitSourceRow

FRONTEND = Path(__file__).resolve().parents[2] / "frontend"
SHELL_HTML = FRONTEND / "index.html"
GIT_SOURCES_JS = FRONTEND / "assets" / "git-sources.js"
STYLES_CSS = FRONTEND / "assets" / "styles.css"

ADD_BRANCH_PLACEHOLDER = "main, release/1.2, …"
EDIT_BRANCH_PLACEHOLDER = "(default branch)"
ADD_HINT_TEXT = "optional — default: the repo's default branch"
EDITOR_HINT_TEXT = "Leave empty for the repo's default branch."
ADD_BODY_EXPR = (
    "(url, token, branch) => ({ url, ...(branch ? { branch } : {}), "
    "...(token ? { token } : {}) })"
)
BRANCH_TAG_CLASS = "git-source-branch-count"
BRANCH_TAG_TEXT_EXPR = "`branch: ${s.branch}`"
TITLE_EXPR = 's.id && s.branch ? `${value} — branch: ${s.branch}` : value'


def _read(path: Path) -> str:
    return path.read_text(encoding="utf-8")


def _js_text() -> str:
    return _read(GIT_SOURCES_JS)


def _fn(js: str, name: str) -> str:
    """The source of a (possibly async) top-level function via
    balanced-brace counting (the test_git_source_token.py helper)."""
    for prefix in ("async function ", "function "):
        start = js.find(f"{prefix}{name}(")
        if start != -1:
            depth = 0
            for i in range(js.find("{", start), len(js)):
                if js[i] == "{":
                    depth += 1
                elif js[i] == "}":
                    depth -= 1
                    if depth == 0:
                        return js[start : i + 1]
            raise AssertionError(f"unbalanced braces in {name}()")
    raise AssertionError(f"{name}() must exist in git-sources.js")


def _input_tag(html: str, id_attr: str) -> str:
    m = re.search(rf"<input[^>]*id=\"{id_attr}\"[^>]*>", html, re.S)
    assert m, f"missing <input id={id_attr}> in the shell"
    return m.group(0)


# ---------------------------------------------------------------------------
# The add form — #git-source-branch (between URL and Token)
# ---------------------------------------------------------------------------


def test_add_form_branch_field_is_optional_text() -> None:
    """``#git-source-branch`` (task 04 step 1): ``type="text"`` (a
    branch is a name, not a credential — no masking), the 200-char cap
    mirrored (the schema's max_length), ``autocomplete="off"``, the
    placeholder, INSIDE ``#git-source-form`` BETWEEN the URL input and
    the Token input (before the submit button), and a visible
    ``<label for=…>`` (WCAG — never aria-label-only) carrying the
    "optional" hint span."""
    html = _read(SHELL_HTML)
    tag = _input_tag(html, "git-source-branch")
    assert 'type="text"' in tag, "the branch is a plain name (no masking)"
    assert 'maxlength="200"' in tag, "the schema cap, mirrored in the form"
    assert 'autocomplete="off"' in tag, "no browser save offer"
    assert ADD_BRANCH_PLACEHOLDER in tag
    form_i = html.find('id="git-source-form"')
    url_i = html.find('id="git-source-url"')
    br_i = html.find('id="git-source-branch"')
    tok_i = html.find('id="git-source-token"')
    btn_i = html.find('id="git-source-add"')
    assert -1 < form_i < url_i < br_i < tok_i < btn_i, (
        "the field sits in the add form, between URL and Token"
    )
    label = re.search(r"<label[^>]*for=\"git-source-branch\"[^>]*>(.*?)</label>", html, re.S)
    assert label, "a visible <label for=…> (never aria-label-only)"
    assert "Branch" in label.group(1)
    hint = re.search(r"<span[^>]*class=\"field-hint\"[^>]*>(.*?)</span>", label.group(1))
    assert hint and hint.group(1) == ADD_HINT_TEXT, "the visible 'optional' hint span"


def test_add_form_submit_omits_a_blank_branch() -> None:
    """The submit body is ``(url, token, branch) => ({ url, ...(branch
    ? { branch } : {}), ...(token ? { token } : {}) })`` — a BLANK
    branch omits the key (NULL = the repo's default branch);
    wireAddForm reads the field (trimmed) and passes it to the body
    callback AFTER the token, and 201 clears all three inputs
    (the credential-free inputs clear together)."""
    js = _js_text()
    assert f"body: {ADD_BODY_EXPR}" in js, "the submit body omits the key when blank"
    wire = _fn(js, "wireAddForm")
    read_i = wire.find('const branch = branchInput ? branchInput.value.trim() : "";')
    tok_i = wire.find('const token = tokenInput ? tokenInput.value.trim() : "";')
    call_i = wire.find("opts.body(value, token, branch)", read_i)
    assert -1 < tok_i < read_i < call_i, (
        "the branch is read (trimmed) after the token and passed to the body"
    )
    clear_url_i = wire.find('input.value = ""')
    clear_tok_i = wire.find('tokenInput.value = ""', clear_url_i)
    clear_br_i = wire.find('branchInput.value = ""', clear_tok_i)
    assert -1 < clear_url_i < clear_tok_i < clear_br_i, "201: all three inputs clear"


def test_add_form_branch_opt_in_the_wire_opts() -> None:
    """The wireAddForm call site threads ``branchInput`` into the opts
    (next to the token lookup — the add form's single wiring point)."""
    js = _js_text()
    lookup_i = js.find('root.querySelector("#git-source-branch")')
    assert lookup_i != -1, "the element lookup next to the token lookups"
    opts = js[js.find("wireAddForm({") :]
    opts = opts[: opts.find("});")]
    assert "branchInput," in opts, "the opts object gains branchInput"


# ---------------------------------------------------------------------------
# The per-row editor — #ignore-editor-branch (git rows only, prefilled,
# empty-save = clear)
# ---------------------------------------------------------------------------


def test_editor_branch_field_sits_after_source_before_textarea() -> None:
    """``#ignore-editor-branch`` (task 04 step 1): ``type="text"`` +
    the 200-char cap + ``autocomplete="off"`` + the "(default branch)"
    placeholder, INSIDE ``#ignore-editor-dialog`` AFTER the source line
    and BEFORE the ignore textarea (before the token field + error
    line), with a visible label and the muted hint line."""
    html = _read(SHELL_HTML)
    tag = _input_tag(html, "ignore-editor-branch")
    assert 'type="text"' in tag
    assert 'maxlength="200"' in tag
    assert 'autocomplete="off"' in tag
    assert f'placeholder="{EDIT_BRANCH_PLACEHOLDER}"' in tag
    dialog_i = html.find('id="ignore-editor-dialog"')
    src_i = html.find('id="ignore-editor-source"')
    br_i = html.find('id="ignore-editor-branch"')
    copy_i = html.find('id="ignore-editor-copy"')
    ta_i = html.find('id="ignore-editor-textarea"')
    tok_i = html.find('id="ignore-editor-token"')
    err_i = html.find('id="ignore-editor-error"')
    assert -1 < dialog_i < src_i < br_i < copy_i < ta_i < tok_i < err_i, (
        "the field sits after the source line, before the ignore textarea"
    )
    label = re.search(r"<label[^>]*for=\"ignore-editor-branch\"[^>]*>(.*?)</label>", html, re.S)
    assert label and "Branch" in label.group(1), "a visible label (WCAG)"
    assert 'class="ignore-editor-label"' in (label.group(0) if label else ""), (
        "the house dialog-label styling"
    )
    hint = re.search(
        r"<p class=\"ignore-editor-branch-hint\">(.*?)</p>", html, re.S
    )
    assert hint and hint.group(1).strip() == EDITOR_HINT_TEXT, "the muted hint line"


def test_editor_opens_prefilled_for_git_hidden_for_local() -> None:
    """openIgnoreEditor: git rows open the branch field prefilled from
    the stored value (``s.branch ?? ""`` — there IS a field to read it
    from, unlike the token) and VISIBLE; local rows HIDE the whole
    field group (label + input + hint — local rows are walked, not
    cloned) and clear the value."""
    js = _js_text()
    open_body = _fn(js, "openIgnoreEditor")
    assert "const branchIsGit = s.kind !== \"local\";" in open_body, (
        "the git-row gate"
    )
    prefill_i = open_body.find('ignoreBranchInput.value = branchIsGit ? (s.branch ?? "") : "";')
    assert prefill_i != -1, "prefilled from the stored value (s.branch ?? \"\")"
    for frag in (
        "ignoreBranchLabel.hidden = !branchIsGit",
        "ignoreBranchHint.hidden = !branchIsGit",
        "ignoreBranchInput.hidden = !branchIsGit",
    ):
        assert frag in open_body, f"the field group hides for local rows: {frag!r}"
    label_i = open_body.find("ignoreBranchLabel.hidden = !branchIsGit")
    hint_i = open_body.find("ignoreBranchHint.hidden = !branchIsGit")
    assert -1 < label_i < hint_i < prefill_i, "the group hides before the prefill"


def test_editor_save_always_sends_branch_for_git_rows() -> None:
    """saveIgnorePaths: the branch is read (trimmed) before the PATCH;
    the git row's body ALWAYS includes ``branch`` —
    ``...(isGitRow ? { branch } : {})`` — an EMPTY value is the
    deliberate CLEAR leg (the tri-state asymmetry, documented at the
    read site), while a LOCAL row's body OMITS the key; the token
    stays the conditional key (blank = keep — untouched) and lands
    AFTER the branch key."""
    js = _js_text()
    save = _fn(js, "saveIgnorePaths")
    read_i = save.find('const branch = ignoreBranchInput ? ignoreBranchInput.value.trim() : "";')
    assert read_i != -1, "the branch is read (trimmed) before the PATCH"
    assert "const isGitRow = t.kind !== \"local\";" in save, "the git-row gate"
    # The asymmetry is documented at the read site (the docstring
    # comment above the read names the clear leg).
    comment_i = save.find("the tri-state ASYMMETRY", 0, read_i)
    assert -1 < comment_i < read_i, "the tri-state asymmetry is documented at the read"
    body_i = save.find("...(isGitRow ? { branch } : {})")
    tok_i = save.find("...(token ? { token } : {})", body_i)
    assert -1 < read_i < body_i < tok_i, (
        "git rows always send branch (\"\" = clear); the token stays conditional"
    )
    assert "ignore_paths: lines" in save[body_i - 60 : body_i + 60], (
        "the ignore_paths replace is untouched"
    )


def test_editor_close_resets_the_branch_field() -> None:
    """closeIgnoreEditor: the branch input resets to "" (it re-opens
    prefilled from the server row — the phase-121 token reset
    precedent, with a prefilled twist)."""
    js = _js_text()
    close_body = _fn(js, "closeIgnoreEditor")
    assert 'ignoreBranchInput.value = ""' in close_body, "resets on close"


# ---------------------------------------------------------------------------
# makeRow — the "branch: <name>" tag + the hover title
# ---------------------------------------------------------------------------


def test_make_row_branch_tag_is_stored_git_rows_only() -> None:
    """makeRow: the ``branch: <name>`` text tag is appended to the
    source cell IFF ``s.id && s.branch`` (env-fallback rows carry no
    id, NULL-branch rows no truthy branch — no tag either way); the
    tag uses the "hidden on" idiom (text + background — the
    .git-source-branch-count class, grouped with
    .git-source-hidden-count in styles.css) and the TEXT is the signal
    (``branch: <name>`` — never color alone)."""
    js = _js_text()
    make = _fn(js, "makeRow")
    guard_i = make.find("if (s.id && s.branch) {")
    assert guard_i != -1, "stored git rows with a branch only"
    block = make[guard_i :]
    block = block[: block.find("\n  }")]
    assert f"branchTag.className = \"{BRANCH_TAG_CLASS}\";" in block
    assert f"branchTag.textContent = {BRANCH_TAG_TEXT_EXPR};" in block, (
        "the text IS the signal (branch: <name>)"
    )
    assert "urlTd.append(branchTag)" in block, "the tag lands in the source cell"
    # The tag comes after the hidden tag (the source-cell tag order:
    # ignored → hidden → branch) and before the cell is appended.
    hidden_i = make.find('hiddenTag.className = "git-source-hidden-count"')
    append_i = make.find("tr.appendChild(urlTd)")
    assert -1 < hidden_i < guard_i < append_i


def test_make_row_title_names_the_branch() -> None:
    """The source cell's title (the hover-precision idiom) includes the
    pinned branch for stored git rows with one; every other row keeps
    the bare value (the pre-phase-135 title — the token E2E's
    to_have_attribute("title", URL) pins stay green)."""
    js = _js_text()
    make = _fn(js, "makeRow")
    assert f"urlTd.title = {TITLE_EXPR};" in make, (
        "the title names the branch (stored git rows only)"
    )


# ---------------------------------------------------------------------------
# Cross-file wire contract — the JS key names match the API shapes
# ---------------------------------------------------------------------------


def test_js_branch_keys_match_the_api_shapes() -> None:
    """The wire contract: the POST body key and the PATCH body key are
    both ``branch`` (task 04 step 3 — the branch rides the existing
    payloads), and every API shape carries the field (task 01/02):
    ``GitSourceIn`` (create), ``GitSourcePatchIn`` (tri-state),
    ``GitSourceOut`` + ``GitSourceRow`` (the row the UI renders —
    ``s.branch`` is read off it). A rename on either side breaks."""
    assert "branch" in GitSourceIn.model_fields
    assert "branch" in GitSourcePatchIn.model_fields
    assert "branch" in GitSourceOut.model_fields
    assert "branch" in GitSourceRow.model_fields
    js = _js_text()
    assert "...(branch ? { branch } : {})" in js, "the POST body key (blank-omits)"
    assert "...(isGitRow ? { branch } : {})" in js, "the PATCH body key (always for git)"
    assert "(s.branch ?? \"\")" in js, "the prefill reads s.branch off the row"


# ---------------------------------------------------------------------------
# The module docstring — the phase-135 paragraph (the house pattern)
# ---------------------------------------------------------------------------


def test_module_docstring_carries_the_phase_135_contract() -> None:
    """The git-sources.js module docstring gained the phase-135
    paragraph (the field, the tri-state asymmetry, the tag rule)."""
    doc = _js_text().split("*/", 2)[0]  # the module docstring (first block)
    for frag in (
        "Phase 135 (task 04)",
        "#git-source-branch",
        "#ignore-editor-branch",
        "s.branch ?? \"\"",
        "THE TRI-STATE ASYMMETRY",
        "branch: <name>",
        "the tag appears/disappears",
    ):
        assert frag in doc, f"the module docstring lost: {frag!r}"


# ---------------------------------------------------------------------------
# styles.css — house-styled rules (no second input language)
# ---------------------------------------------------------------------------


def test_branch_field_css_rules_are_house_styled() -> None:
    """styles.css: the add form's branch input joins the URL/token box
    group (mono, >=44px floor, placeholder + focus rules); the editor's
    branch field is full panel width at the 44px floor (the token
    field's box language); the hint line carries the .field-hint values
    (ink-soft, 0.8rem); the row tag joins the .git-source-hidden-count
    rule (text + a distinct background, never color alone); the mobile
    squeeze groups the add input with URL/token."""
    css = _read(STYLES_CSS)
    grouped = css.find("#git-source-url,\n#git-source-branch,\n#git-source-token {")
    assert grouped != -1, "#git-source-branch shares the URL/token box"
    rule = css[grouped : css.find("}", grouped)]
    assert "min-height: 44px" in rule and "var(--mono)" in rule
    assert "#git-source-branch::placeholder" in css, "the muted placeholder"
    assert "#git-source-branch:focus-visible" in css, "the brand focus border"
    br = css.find("#ignore-editor-branch {")
    assert br != -1, "the editor's branch field rule"
    br_rule = css[br : css.find("}", br)]
    assert "width: 100%" in br_rule and "min-height: 44px" in br_rule
    hint = css.find(".ignore-editor-branch-hint {")
    assert hint != -1, "the muted hint line rule"
    hint_rule = css[hint : css.find("}", hint)]
    assert "var(--ink-soft)" in hint_rule and "font-size: 0.8rem" in hint_rule, (
        "the .field-hint values (the token field's hint styling)"
    )
    # Phase 191 (task 03): the name/label/tags row's two tags ("named" and
    # one tag chip) joined this SAME rule — the reuse that keeps the token
    # input from shipping its own tag CSS.
    tag = css.find(
        ".git-source-hidden-count,\n.git-source-branch-count,\n"
        ".source-label-state,\n.source-label-tag {"
    )
    assert tag != -1, "the row tag joins the 'hidden on' tag rule"
    tag_rule = css[tag : css.find("}", tag)]
    assert "background: var(--bg)" in tag_rule and "border" in tag_rule, (
        "text + background (never color alone — WCAG 1.4.1)"
    )
    mobile = css.find("#git-source-url,\n  #git-source-branch,\n  #git-source-token,")
    assert mobile != -1, "the mobile squeeze groups the branch input"