// Copyright 2018-2026 the Deno authors. MIT license.

use std::borrow::Cow;
use std::collections::BTreeMap;
use std::path::Path;
use std::sync::Arc;

use deno_ast::MediaType;
use deno_ast::diagnostics::Diagnostic;
use deno_ast::diagnostics::DiagnosticLevel;
use deno_ast::diagnostics::DiagnosticLocation;
use deno_ast::diagnostics::DiagnosticSnippet;
use deno_ast::diagnostics::DiagnosticSnippetHighlight;
use deno_ast::diagnostics::DiagnosticSnippetHighlightStyle;
use deno_ast::diagnostics::DiagnosticSourcePos;
use deno_ast::diagnostics::DiagnosticSourceRange;
use deno_config::glob::FilePatterns;
use deno_config::glob::PathOrPatternSet;
use deno_core::anyhow::Context;
use deno_core::anyhow::bail;
use deno_core::error::AnyError;
use deno_core::serde_json;
use deno_doc as doc;
use deno_doc::Document;
use deno_doc::ParseOutput;
use deno_doc::html::UrlResolveKind;
use deno_doc::html::UsageComposer;
use deno_doc::html::UsageComposerEntry;
use deno_doc::js_doc::JsDoc;
use deno_graph::CheckJsOption;
use deno_graph::GraphKind;
use deno_graph::ModuleSpecifier;
use deno_graph::analysis::ModuleAnalyzer;
use deno_graph::ast::EsParser;
use deno_graph::source::NullFileSystem;
use deno_lib::version::DENO_VERSION_INFO;
use deno_npm_installer::graph::NpmCachingStrategy;
use doc::DocDiagnostic;
use doc::html::ShortPath;
use indexmap::IndexMap;
use indexmap::IndexSet;

use crate::args::DocFlags;
use crate::args::DocHtmlFlag;
use crate::args::DocSourceFileFlag;
use crate::args::Flags;
use crate::colors;
use crate::display;
use crate::factory::CliFactory;
use crate::file_fetcher::TextDecodedFile;
use crate::graph_util::GraphWalkErrorsOptions;
use crate::graph_util::graph_exit_integrity_errors;
use crate::graph_util::graph_walk_errors;
use crate::sys::CliSys;
use crate::tsc::get_types_declaration_file_text;
use crate::util::fs::CollectSpecifiersOptions;
use crate::util::fs::collect_specifiers;

const JSON_SCHEMA_VERSION: u8 = 2;

const PRISM_CSS: &str = include_str!("./doc/prism.css");
const PRISM_JS: &str = include_str!("./doc/prism.js");

fn char_highlight_end(text: &str, start_byte_index: usize) -> usize {
  if start_byte_index >= text.len() {
    return start_byte_index;
  }
  if let Some(text) = text.get(start_byte_index..) {
    return start_byte_index
      + text.chars().next().map(|c| c.len_utf8()).unwrap_or(1);
  }
  let mut end_byte_index = start_byte_index + 1;
  while end_byte_index < text.len() && !text.is_char_boundary(end_byte_index) {
    end_byte_index += 1;
  }
  end_byte_index
}

struct DisplayDocDiagnostic<'a>(&'a DocDiagnostic);

impl Diagnostic for DisplayDocDiagnostic<'_> {
  fn level(&self) -> DiagnosticLevel {
    self.0.level()
  }

  fn code(&self) -> Cow<'_, str> {
    self.0.code()
  }

  fn message(&self) -> Cow<'_, str> {
    self.0.message()
  }

  fn location(&self) -> DiagnosticLocation<'_> {
    self.0.location()
  }

  fn snippet(&self) -> Option<DiagnosticSnippet<'_>> {
    let start_byte_index = self.0.location.byte_index;
    Some(DiagnosticSnippet {
      source: Cow::Borrowed(&self.0.text_info),
      highlights: vec![DiagnosticSnippetHighlight {
        style: DiagnosticSnippetHighlightStyle::Error,
        range: DiagnosticSourceRange {
          start: DiagnosticSourcePos::ByteIndex(start_byte_index),
          end: DiagnosticSourcePos::ByteIndex(char_highlight_end(
            self.0.text_info.text_str(),
            start_byte_index,
          )),
        },
        description: None,
      }],
    })
  }

  fn hint(&self) -> Option<Cow<'_, str>> {
    self.0.hint()
  }

  fn snippet_fixed(&self) -> Option<DiagnosticSnippet<'_>> {
    match &self.0.kind {
      doc::DocDiagnosticKind::PrivateTypeRef(diagnostic) => {
        let start_byte_index = diagnostic.reference_location.byte_index;
        Some(DiagnosticSnippet {
          source: Cow::Borrowed(&diagnostic.reference_text_info),
          highlights: vec![DiagnosticSnippetHighlight {
            style: DiagnosticSnippetHighlightStyle::Hint,
            range: DiagnosticSourceRange {
              start: DiagnosticSourcePos::ByteIndex(start_byte_index),
              end: DiagnosticSourcePos::ByteIndex(char_highlight_end(
                diagnostic.reference_text_info.text_str(),
                start_byte_index,
              )),
            },
            description: Some(Cow::Borrowed("this is the referenced type")),
          }],
        })
      }
      _ => None,
    }
  }

  fn info(&self) -> Cow<'_, [Cow<'_, str>]> {
    self.0.info()
  }

  fn docs_url(&self) -> Option<Cow<'_, str>> {
    self.0.docs_url()
  }
}

async fn generate_doc_nodes_for_builtin_types(
  doc_flags: DocFlags,
  parser: &dyn EsParser,
  analyzer: &dyn ModuleAnalyzer,
) -> Result<ParseOutput, AnyError> {
  let source_file_specifier =
    ModuleSpecifier::parse("file:///lib.deno.d.ts").unwrap();
  let content = get_types_declaration_file_text();
  let loader = deno_graph::source::MemoryLoader::new(
    vec![(
      source_file_specifier.to_string(),
      deno_graph::source::Source::Module {
        specifier: source_file_specifier.to_string(),
        content,
        maybe_headers: None,
      },
    )],
    Vec::new(),
  );
  let roots = vec![source_file_specifier.clone()];
  let mut graph = deno_graph::ModuleGraph::new(GraphKind::TypesOnly);
  graph
    .build(
      roots.clone(),
      Vec::new(),
      &loader,
      deno_graph::BuildOptions {
        is_dynamic: false,
        skip_dynamic_deps: false,
        passthrough_jsr_specifiers: false,
        executor: Default::default(),
        file_system: &NullFileSystem,
        jsr_metadata_store: None,
        jsr_url_provider: Default::default(),
        jsr_version_resolver: Default::default(),
        locker: None,
        module_analyzer: analyzer,
        module_info_cacher: Default::default(),
        npm_resolver: None,
        reporter: None,
        resolver: None,
        unstable_bytes_imports: false,
        unstable_text_imports: true,
        unstable_css_imports: false,
        unstable_config_imports: false,
      },
    )
    .await;
  let doc_parser = doc::DocParser::new(
    &graph,
    parser,
    &roots,
    doc::DocParserOptions {
      diagnostics: false,
      private: doc_flags.private,
    },
  )?;
  Ok(doc_parser.parse()?)
}

pub async fn doc(
  flags: Arc<Flags>,
  doc_flags: DocFlags,
) -> Result<(), AnyError> {
  let factory = CliFactory::from_flags(flags);
  let cli_options = factory.cli_options()?;
  let module_info_cache = factory.module_info_cache()?;
  let parsed_source_cache = factory.parsed_source_cache()?;
  let capturing_parser = parsed_source_cache.as_capturing_parser();
  let analyzer = module_info_cache.as_module_analyzer();
  let file_fetcher = factory.file_fetcher()?;

  let documents_by_url = match doc_flags.source_files {
    DocSourceFileFlag::Builtin => {
      generate_doc_nodes_for_builtin_types(
        doc_flags.clone(),
        &capturing_parser,
        &analyzer,
      )
      .await?
    }
    DocSourceFileFlag::Paths(ref source_files) => {
      let module_graph_creator = factory.module_graph_creator().await?;
      let sys = CliSys::default();

      let module_specifiers = collect_specifiers(
        CollectSpecifiersOptions {
          file_patterns: FilePatterns {
            base: cli_options.initial_cwd().to_path_buf(),
            include: Some(
              PathOrPatternSet::from_include_relative_path_or_patterns(
                cli_options.initial_cwd(),
                source_files,
              )?,
            ),
            exclude: Default::default(),
          },
          vendor_folder: cli_options.vendor_dir_path().map(ToOwned::to_owned),
          include_ignored_specified: false,
        },
        |_| true,
      )?;

      let graph = module_graph_creator
        .create_graph(
          GraphKind::TypesOnly,
          module_specifiers.clone(),
          NpmCachingStrategy::Eager,
        )
        .await?;

      // building the graph may have changed npm specifiers to
      // file: specifiers, so get the new roots
      let mut module_specifiers =
        graph.roots.iter().cloned().collect::<Vec<_>>();

      graph_exit_integrity_errors(&graph);
      let collect_bare_importable_pkg_names = Vec::<String>::new;
      let errors = graph_walk_errors(
        &graph,
        &sys,
        &module_specifiers,
        GraphWalkErrorsOptions {
          check_js: CheckJsOption::False,
          kind: GraphKind::TypesOnly,
          will_type_check: false,
          allow_unknown_media_types: false,
          allow_unknown_jsr_exports: false,
          collect_bare_importable_pkg_names: &collect_bare_importable_pkg_names,
        },
      );
      let mut markdown_urls = IndexSet::new();
      for error in errors {
        if let Some(deno_graph::ModuleErrorKind::UnsupportedMediaType {
          media_type: MediaType::Markdown,
          specifier,
          ..
        }) = error.original().as_module_error_kind()
        {
          markdown_urls.insert(specifier.clone());
        } else {
          log::warn!("{} {}", colors::yellow("Warning"), error);
        }
      }

      module_specifiers.retain(|s| {
        !markdown_urls.contains(s) && !markdown_urls.contains(graph.resolve(s))
      });

      let doc_parser = doc::DocParser::new(
        &graph,
        &capturing_parser,
        &module_specifiers,
        doc::DocParserOptions {
          private: doc_flags.private,
          diagnostics: doc_flags.lint,
        },
      )?;
      let mut doc_nodes_by_url = doc_parser.parse()?;

      if doc_flags.lint {
        let mut diagnostics = doc_parser.take_diagnostics();
        // Drop private-type-ref diagnostics whose referenced type lives
        // in a different package (i.e. a non-file specifier such as
        // jsr:, npm:, http:, https:). Those types' visibility is the
        // upstream package's concern, not the current package's.
        diagnostics.retain(|diagnostic| match &diagnostic.kind {
          doc::DocDiagnosticKind::PrivateTypeRef(d) => {
            d.reference_location.filename.starts_with("file:")
          }
          _ => true,
        });
        check_diagnostics(&diagnostics)?;
      }

      let markdown_downloads = deno_core::futures::future::try_join_all(
        markdown_urls.into_iter().map(|url| async {
          // ok to skip permissions because these were provided on the CLI
          let file = file_fetcher.fetch_bypass_permissions(&url).await?;
          let decoded = TextDecodedFile::decode(file)?;
          Ok::<_, AnyError>((url, decoded))
        }),
      )
      .await?;
      for (url, decoded) in markdown_downloads {
        doc_nodes_by_url.insert(
          url,
          Document {
            module_doc: JsDoc {
              doc: Some(Box::from(&*decoded.source)),
              tags: Default::default(),
            },
            imports: Default::default(),
            symbols: Default::default(),
          },
        );
      }

      doc_nodes_by_url
    }
  };

  if let Some(html_options) = &doc_flags.html {
    let deno_ns = if doc_flags.source_files != DocSourceFileFlag::Builtin {
      let deno_ns = generate_doc_nodes_for_builtin_types(
        doc_flags.clone(),
        &capturing_parser,
        &analyzer,
      )
      .await?;
      let (_, deno_ns) = deno_ns.into_iter().next().unwrap();

      Some(deno_ns)
    } else {
      None
    };

    let mut main_entrypoint = None;

    let rewrite_map = if let Some(config_file) =
      cli_options.start_dir.member_or_root_deno_json()
    {
      let config = config_file.to_exports_config()?;

      main_entrypoint = config.get_resolved(".").ok().flatten();

      let rewrite_map = config
        .clone()
        .into_map()
        .into_keys()
        .map(|key| {
          Ok((
            config.get_resolved(&key)?.unwrap(),
            key
              .strip_prefix('.')
              .unwrap_or(&key)
              .strip_prefix('/')
              .unwrap_or(&key)
              .to_owned(),
          ))
        })
        .collect::<Result<IndexMap<_, _>, AnyError>>()?;

      Some(rewrite_map)
    } else {
      None
    };

    generate_docs_directory(
      cli_options.initial_cwd(),
      documents_by_url,
      html_options,
      deno_ns,
      rewrite_map,
      main_entrypoint,
    )
  } else {
    let modules_len = documents_by_url.len();

    if doc_flags.json {
      let json_output = serde_json::json!({
        "version": JSON_SCHEMA_VERSION,
        "nodes": &documents_by_url
      });
      display::write_json_to_stdout(&json_output)
    } else if doc_flags.lint {
      // don't output docs if running with only the --lint flag
      log::info!(
        "Checked {} file{}",
        modules_len,
        if modules_len == 1 { "" } else { "s" }
      );
      Ok(())
    } else {
      print_docs_to_stdout(doc_flags, documents_by_url)
    }
  }
}

struct DocResolver {
  deno_ns: std::collections::HashMap<Vec<String>, Option<Arc<ShortPath>>>,
  strip_trailing_html: bool,
}

impl deno_doc::html::HrefResolver for DocResolver {
  fn resolve_path(
    &self,
    current: UrlResolveKind,
    target: UrlResolveKind,
  ) -> String {
    let path = deno_doc::html::href_path_resolve(current, target);
    if self.strip_trailing_html
      && let Some(path) = path
        .strip_suffix("index.html")
        .or_else(|| path.strip_suffix(".html"))
    {
      return path.to_owned();
    }

    path
  }

  fn resolve_global_symbol(&self, symbol: &[String]) -> Option<String> {
    if self.deno_ns.contains_key(symbol) {
      Some(format!(
        "https://deno.land/api@v{}?s={}",
        DENO_VERSION_INFO.deno,
        symbol.join(".")
      ))
    } else {
      None
    }
  }

  fn resolve_import_href(
    &self,
    symbol: &[String],
    src: &str,
  ) -> Option<String> {
    let mut url = ModuleSpecifier::parse(src).ok()?;

    if url.domain() == Some("deno.land") {
      url.set_query(Some(&format!("s={}", symbol.join("."))));
      return Some(url.into());
    }

    None
  }

  fn resolve_source(&self, location: &deno_doc::Location) -> Option<String> {
    Some(location.filename.to_string())
  }

  fn resolve_external_jsdoc_module(
    &self,
    module: &str,
    _symbol: Option<&str>,
  ) -> Option<(String, String)> {
    if let Ok(url) = deno_core::url::Url::parse(module) {
      match url.scheme() {
        "npm" => {
          let res =
            deno_semver::npm::NpmPackageReqReference::from_str(module).ok()?;
          let name = &res.req().name;
          Some((
            format!("https://www.npmjs.com/package/{name}"),
            name.to_string(),
          ))
        }
        "jsr" => {
          let res =
            deno_semver::jsr::JsrPackageReqReference::from_str(module).ok()?;
          let name = &res.req().name;
          Some((format!("https://jsr.io/{name}"), name.to_string()))
        }
        _ => None,
      }
    } else {
      None
    }
  }
}

struct DocComposer;

impl UsageComposer for DocComposer {
  fn is_single_mode(&self) -> bool {
    true
  }

  fn compose(
    &self,
    current_resolve: UrlResolveKind,
    usage_to_md: deno_doc::html::UsageToMd,
  ) -> IndexMap<UsageComposerEntry, String> {
    current_resolve
      .get_file()
      .map(|current_file| {
        IndexMap::from([(
          UsageComposerEntry {
            name: "".to_string(),
            icon: None,
          },
          usage_to_md(current_file.path.as_str(), None),
        )])
      })
      .unwrap_or_default()
  }
}

fn generate_docs_directory(
  cwd: &Path,
  documents_by_url: ParseOutput,
  html_options: &DocHtmlFlag,
  built_in_types: Option<Document>,
  rewrite_map: Option<IndexMap<ModuleSpecifier, String>>,
  main_entrypoint: Option<ModuleSpecifier>,
) -> Result<(), AnyError> {
  let output_dir_resolved = cwd.join(&html_options.output);

  let category_docs =
    if let Some(category_docs_path) = &html_options.category_docs_path {
      let content = std::fs::read(category_docs_path)?;
      Some(serde_json::from_slice(&content)?)
    } else {
      None
    };

  let symbol_redirect_map = if let Some(symbol_redirect_map_path) =
    &html_options.symbol_redirect_map_path
  {
    let content = std::fs::read(symbol_redirect_map_path)?;
    Some(serde_json::from_slice(&content)?)
  } else {
    None
  };

  let default_symbol_map = if let Some(default_symbol_map_path) =
    &html_options.default_symbol_map_path
  {
    let content = std::fs::read(default_symbol_map_path)?;
    Some(serde_json::from_slice(&content)?)
  } else {
    None
  };

  let mut options = deno_doc::html::GenerateOptions {
    package_name: html_options.name.clone(),
    main_entrypoint,
    rewrite_map,
    href_resolver: Arc::new(DocResolver {
      deno_ns: Default::default(),
      strip_trailing_html: html_options.strip_trailing_html,
    }),
    usage_composer: Some(Arc::new(DocComposer)),
    category_docs,
    disable_search: false,
    symbol_redirect_map,
    default_symbol_map,
    diff_only: false,
    markdown_renderer: deno_doc::html::comrak::create_renderer(
      None, None, None,
    ),
    markdown_stripper: Arc::new(deno_doc::html::comrak::strip),
    head_inject: Some(Arc::new(|root| {
      format!(
        r#"<link href="{root}{}" rel="stylesheet" /><link href="{root}prism.css" rel="stylesheet" /><script src="{root}prism.js"></script>"#,
        deno_doc::html::comrak::COMRAK_STYLESHEET_FILENAME
      )
    })),
    id_prefix: None,
  };

  if let Some(built_in_types) = built_in_types {
    let ctx = deno_doc::html::GenerateCtx::create_basic(
      deno_doc::html::GenerateOptions {
        package_name: None,
        main_entrypoint: Some(
          ModuleSpecifier::parse("file:///lib.deno.d.ts").unwrap(),
        ),
        href_resolver: Arc::new(DocResolver {
          deno_ns: Default::default(),
          strip_trailing_html: false,
        }),
        usage_composer: Some(Arc::new(DocComposer)),
        rewrite_map: Default::default(),
        category_docs: Default::default(),
        disable_search: Default::default(),
        symbol_redirect_map: Default::default(),
        default_symbol_map: Default::default(),
        diff_only: false,
        markdown_renderer: deno_doc::html::comrak::create_renderer(
          None, None, None,
        ),
        markdown_stripper: Arc::new(deno_doc::html::comrak::strip),
        head_inject: None,
        id_prefix: None,
      },
      IndexMap::from([(
        ModuleSpecifier::parse("file:///lib.deno.d.ts").unwrap(),
        built_in_types,
      )]),
      None,
    )?;

    let deno_ns = deno_doc::html::compute_namespaced_symbols(
      &ctx,
      Box::new(
        ctx
          .doc_nodes
          .values()
          .next()
          .unwrap()
          .iter()
          .map(std::borrow::Cow::Borrowed),
      ),
    );

    options.href_resolver = Arc::new(DocResolver {
      deno_ns,
      strip_trailing_html: html_options.strip_trailing_html,
    });
  }

  let ctx =
    deno_doc::html::GenerateCtx::create_basic(options, documents_by_url, None)?;

  let mut files = deno_doc::html::generate(ctx)
    .context("Failed to generate HTML documentation")?;

  files.insert("prism.js".to_string(), PRISM_JS.to_string());
  files.insert("prism.css".to_string(), PRISM_CSS.to_string());

  let path = &output_dir_resolved;
  let _ = std::fs::remove_dir_all(path);
  std::fs::create_dir(path)
    .with_context(|| format!("Failed to create directory {:?}", path))?;

  let no_of_files = files.len();
  for (name, content) in files {
    let this_path = path.join(name);
    let prefix = this_path.parent().with_context(|| {
      format!("Failed to get parent path for {:?}", this_path)
    })?;
    std::fs::create_dir_all(prefix)
      .with_context(|| format!("Failed to create directory {:?}", prefix))?;
    std::fs::write(&this_path, content)
      .with_context(|| format!("Failed to write file {:?}", this_path))?;
  }

  log::info!(
    "{}",
    colors::green(format!(
      "Written {} files to {:?}",
      no_of_files, html_options.output
    ))
  );
  Ok(())
}

fn print_docs_to_stdout(
  doc_flags: DocFlags,
  mut documents_by_url: ParseOutput,
) -> Result<(), AnyError> {
  if let Some(filter) = doc_flags.filter {
    for (_, doc) in &mut documents_by_url {
      let symbols = std::mem::take(&mut doc.symbols);
      doc.symbols = doc::find_nodes_by_name_recursively(symbols, &filter)
        .into_iter()
        .map(Arc::new)
        .collect();
      if doc.symbols.is_empty() {
        bail!("Node {} was not found!", filter);
      }
    }
  }

  let details = format!(
    "{}",
    doc::DocPrinter::new(
      &documents_by_url,
      colors::use_color(),
      doc_flags.private
    )
  );

  deno_print::drop_write_stdout(details.as_bytes());
  Ok(())
}

fn check_diagnostics(diagnostics: &[DocDiagnostic]) -> Result<(), AnyError> {
  if diagnostics.is_empty() {
    return Ok(());
  }

  // group by location then by line (sorted) then column (sorted)
  let mut diagnostic_groups = IndexMap::new();
  for diagnostic in diagnostics {
    diagnostic_groups
      .entry(diagnostic.location.filename.clone())
      .or_insert_with(BTreeMap::new)
      .entry(diagnostic.location.line)
      .or_insert_with(BTreeMap::new)
      .entry(diagnostic.location.col)
      .or_insert_with(Vec::new)
      .push(diagnostic);
  }

  for (_, diagnostics_by_lc) in diagnostic_groups {
    for (_, diagnostics_by_col) in diagnostics_by_lc {
      for (_, diagnostics) in diagnostics_by_col {
        for diagnostic in diagnostics {
          log::error!("{}\n", DisplayDocDiagnostic(diagnostic).display());
        }
      }
    }
  }
  bail!(
    "Found {} documentation lint error{}.",
    colors::bold(diagnostics.len().to_string()),
    if diagnostics.len() == 1 { "" } else { "s" }
  );
}
