#!/usr/bin/env -S uv run --script
# /// script
# requires-python = ">=3.12"
# dependencies = ["rich==15.0.0"]
# ///
#MISE description="Validate all wiki-links point to existing doc files"
"""Validate that all wiki-links in documentation point to existing files.

This script scans all markdown files in the docs/ directory (excluding
changelog.d/), extracts wiki-links, and verifies each link target resolves
to an existing file.

Wiki-link formats supported:
- [[filename]] - resolves by stem (errors if ambiguous)
- [[path/to/file]] - resolves by relative path from docs root
- [[target|Display Text]] - either form with display text
- [[target#Heading]] - with anchor fragment (file part validated)

Resolution mirrors Quartz's "shortest" markdownLinkResolution:
bare names resolve when unique; use paths to disambiguate duplicates.

Usage: mise run docs-check-links
"""

import re
import sys
from pathlib import Path

from rich.console import Console
from rich.markup import escape
from rich.table import Table

DOCS_DIR = Path(__file__).parent.parent / "docs"

# Regex to match wiki-links: [[Target]] or [[Target|Display]]
WIKILINK_PATTERN = re.compile(r"\[\[([^\]|]+)(\|[^\]]+)?\]\]")

# Regex to match inline code (backticks)
INLINE_CODE_PATTERN = re.compile(r"`[^`]+`")


def extract_wikilinks(file_path: Path) -> list[tuple[str, int, bool]]:
    """Extract all wiki-link targets from a markdown file with line numbers.

    Returns list of (target, line_num, has_spaces) tuples.
    has_spaces is True if the target or pipe separator had surrounding spaces.

    Ignores wiki-links inside inline code (backticks) as these are examples.
    """
    content = file_path.read_text()
    links = []

    for line_num, line in enumerate(content.splitlines(), start=1):
        # Remove inline code before searching for wiki-links
        line_without_code = INLINE_CODE_PATTERN.sub("", line)
        for match in WIKILINK_PATTERN.finditer(line_without_code):
            raw_target = match.group(1)
            target = raw_target.strip()
            pipe_part = match.group(2)  # "|Display" or None
            # Check for spaces: in target, or around the pipe
            has_spaces = raw_target != target
            if pipe_part and (raw_target.endswith(" ") or pipe_part.startswith("| ")):
                has_spaces = True
            links.append((target, line_num, has_spaces))

    return links


def main() -> int:
    console = Console()

    # Build lookup structures:
    # - path_targets: set of relative paths without extension (e.g., "reference/services/alloy")
    # - stem_to_paths: map from filename stem to list of paths (for ambiguity detection)
    path_targets: set[str] = set()
    stem_to_paths: dict[str, list[str]] = {}

    for md_file in DOCS_DIR.rglob("*.md"):
        if "changelog.d" in md_file.parts:
            continue
        stem = md_file.stem
        rel_path_str = str(md_file.relative_to(DOCS_DIR).with_suffix(""))
        path_targets.add(rel_path_str)
        if stem not in stem_to_paths:
            stem_to_paths[stem] = []
        stem_to_paths[stem].append(rel_path_str)

    # Special case: files at repo root copied into docs during build
    REPO_ROOT = DOCS_DIR.parent
    BUILD_TIME_DOCS = ["CHANGELOG.md"]
    for filename in BUILD_TIME_DOCS:
        if (REPO_ROOT / filename).exists():
            stem = Path(filename).stem
            if stem not in stem_to_paths:
                stem_to_paths[stem] = []
            stem_to_paths[stem].append(stem)
            path_targets.add(stem)

    # Collect errors
    broken_links: list[tuple[str, int, str]] = []
    ambiguous_links: list[tuple[str, int, str, list[str]]] = []
    spaced_links: list[tuple[str, int, str]] = []

    # Track linked stems for orphan detection
    all_doc_stems: set[str] = set(stem_to_paths.keys())
    linked_stems: set[str] = set()

    for md_file in sorted(DOCS_DIR.rglob("*.md")):
        if "changelog.d" in md_file.parts:
            continue

        rel_path = str(md_file.relative_to(DOCS_DIR))
        source_stem = md_file.stem
        links = extract_wikilinks(md_file)

        for target, line_num, has_spaces in links:
            if has_spaces:
                spaced_links.append((rel_path, line_num, target))
                continue

            # Strip anchor fragment for file validation
            file_target = target
            if "#" in target:
                file_target = target.split("#", 1)[0]
                if not file_target:
                    # Pure in-page anchor like [[#Heading]] — always valid
                    continue

            if "/" in file_target:
                # Path-based link — resolve against path_targets
                if file_target not in path_targets:
                    broken_links.append((rel_path, line_num, target))
                else:
                    # Extract the stem for orphan tracking
                    linked_stem = file_target.rsplit("/", 1)[-1]
                    if linked_stem != source_stem:
                        linked_stems.add(linked_stem)
            else:
                # Bare stem link — check for existence and ambiguity
                paths = stem_to_paths.get(file_target)
                if paths is None:
                    broken_links.append((rel_path, line_num, target))
                elif len(paths) > 1:
                    # Ambiguous: multiple files share this stem
                    ambiguous_links.append((rel_path, line_num, target, paths))
                elif file_target != source_stem:
                    linked_stems.add(file_target)

    # Print results
    console.print("[bold]Wiki-Link Validation[/bold]")
    console.print()
    console.print(f"Found {len(path_targets)} valid link targets in documentation.")
    console.print()

    has_errors = False

    if spaced_links:
        has_errors = True
        console.print("[bold red]Wiki-Links With Spaces Found[/bold red]")
        console.print("Wiki-links must not have spaces in the target or around the pipe.")
        console.print("Use [[target|Display Text]] not [[target | Display Text]].")
        console.print()
        table = Table(show_header=True, header_style="bold")
        table.add_column("File")
        table.add_column("Line", justify="right")
        table.add_column("Target")

        for file_path, line_num, target in spaced_links:
            table.add_row(file_path, str(line_num), escape(f"[[{target}]]"))

        console.print(table)
        console.print()

    if ambiguous_links:
        has_errors = True
        console.print("[bold red]Ambiguous Wiki-Links Found[/bold red]")
        console.print("These bare-name links match multiple files.")
        console.print("Use a path-based link to disambiguate: [[path/to/file]]")
        console.print()
        table = Table(show_header=True, header_style="bold")
        table.add_column("File")
        table.add_column("Line", justify="right")
        table.add_column("Target")
        table.add_column("Possible Paths")

        for file_path, line_num, target, paths in ambiguous_links:
            table.add_row(file_path, str(line_num), escape(f"[[{target}]]"), "\n".join(paths))

        console.print(table)
        console.print()

    if broken_links:
        has_errors = True
        console.print("[bold red]Broken Wiki-Links Found[/bold red]")
        table = Table(show_header=True, header_style="bold")
        table.add_column("File")
        table.add_column("Line", justify="right")
        table.add_column("Target")

        for file_path, line_num, target in broken_links:
            table.add_row(file_path, str(line_num), escape(f"[[{target}]]"))

        console.print(table)
        console.print()
        console.print("Each wiki-link target must match a filename stem or path in docs/.")
        console.print()

    # Orphan detection: docs not linked from any other doc
    ORPHAN_EXCEPTIONS = {"index"}
    orphan_stems = sorted(all_doc_stems - linked_stems - ORPHAN_EXCEPTIONS)
    if orphan_stems:
        has_errors = True
        console.print("[bold red]Orphan Documents Found[/bold red]")
        console.print("These docs are not linked from any other document.")
        console.print()
        table = Table(show_header=True, header_style="bold")
        table.add_column("File")
        table.add_column("Stem")

        for stem in orphan_stems:
            paths = stem_to_paths[stem]
            for path in paths:
                table.add_row(f"{path}.md", stem)

        console.print(table)
        console.print()

    if has_errors:
        return 1

    console.print("[bold green]All wiki-links are valid![/bold green]")
    return 0


if __name__ == "__main__":
    sys.exit(main())