// Copyright 2018-2024 the Deno authors. All rights reserved. MIT license.

use std::collections::HashSet;
use std::collections::VecDeque;

use deno_ast::ModuleSpecifier;
use deno_config::ConfigFile;
use deno_config::WorkspaceConfig;
use deno_core::anyhow::bail;
use deno_core::anyhow::Context;
use deno_core::error::AnyError;
use deno_graph::FastCheckDiagnostic;
use deno_graph::ModuleEntryRef;
use deno_graph::ModuleGraph;
use deno_graph::ResolutionResolved;
use deno_graph::WalkOptions;
use lsp_types::Url;

use super::diagnostics::PublishDiagnostic;
use super::diagnostics::PublishDiagnosticsCollector;

#[derive(Debug)]
pub struct MemberRoots {
  pub name: String,
  pub dir_url: ModuleSpecifier,
  pub exports: Vec<ModuleSpecifier>,
}

pub fn get_workspace_member_roots(
  config: &WorkspaceConfig,
) -> Result<Vec<MemberRoots>, AnyError> {
  let mut members = Vec::with_capacity(config.members.len());
  let mut seen_names = HashSet::with_capacity(config.members.len());
  for member in &config.members {
    if !seen_names.insert(&member.package_name) {
      bail!(
        "Cannot have two workspace packages with the same name ('{}' at {})",
        member.package_name,
        member.path.display(),
      );
    }
    members.push(MemberRoots {
      name: member.package_name.clone(),
      dir_url: member.config_file.specifier.join("./").unwrap().clone(),
      exports: resolve_config_file_roots_from_exports(&member.config_file)?,
    });
  }
  Ok(members)
}

pub fn resolve_config_file_roots_from_exports(
  config_file: &ConfigFile,
) -> Result<Vec<ModuleSpecifier>, AnyError> {
  let exports_config = config_file
    .to_exports_config()
    .with_context(|| {
      format!("Failed to parse exports at {}", config_file.specifier)
    })?
    .into_map();
  let mut exports = Vec::with_capacity(exports_config.len());
  for (_, value) in exports_config {
    let entry_point =
      config_file.specifier.join(&value).with_context(|| {
        format!("Failed to join {} with {}", config_file.specifier, value)
      })?;
    exports.push(entry_point);
  }
  Ok(exports)
}

pub fn collect_invalid_external_imports(
  graph: &ModuleGraph,
  diagnostics_collector: &PublishDiagnosticsCollector,
) {
  let mut visited = HashSet::new();
  let mut skip_specifiers: HashSet<Url> = HashSet::new();

  let mut collect_if_invalid =
    |skip_specifiers: &mut HashSet<Url>, resolution: &ResolutionResolved| {
      if visited.insert(resolution.specifier.clone()) {
        match resolution.specifier.scheme() {
          "file" | "data" => {}
          "jsr" | "npm" => {
            skip_specifiers.insert(resolution.specifier.clone());
          }
          "http" | "https" => {
            skip_specifiers.insert(resolution.specifier.clone());
            diagnostics_collector.push(
              PublishDiagnostic::InvalidExternalImport {
                kind: format!("non-JSR '{}'", resolution.specifier.scheme()),
                imported: resolution.specifier.clone(),
                referrer: resolution.range.clone(),
              },
            );
          }
          _ => {
            skip_specifiers.insert(resolution.specifier.clone());
            diagnostics_collector.push(
              PublishDiagnostic::InvalidExternalImport {
                kind: format!("'{}'", resolution.specifier.scheme()),
                imported: resolution.specifier.clone(),
                referrer: resolution.range.clone(),
              },
            );
          }
        }
      }
    };

  let options = WalkOptions {
    check_js: true,
    follow_dynamic: true,
    follow_type_only: true,
  };
  let mut iter = graph.walk(&graph.roots, options);
  while let Some((specifier, entry)) = iter.next() {
    if skip_specifiers.contains(specifier) {
      iter.skip_previous_dependencies();
      continue;
    }

    let ModuleEntryRef::Module(module) = entry else {
      continue;
    };
    let Some(module) = module.esm() else {
      continue;
    };

    for (_, dep) in &module.dependencies {
      if let Some(resolved) = dep.maybe_code.ok() {
        collect_if_invalid(&mut skip_specifiers, resolved);
      }
      if let Some(resolved) = dep.maybe_type.ok() {
        collect_if_invalid(&mut skip_specifiers, resolved);
      }
    }
  }
}

/// Collects diagnostics from the module graph for the given packages.
/// Returns true if any diagnostics were collected.
pub fn collect_fast_check_type_graph_diagnostics(
  graph: &ModuleGraph,
  packages: &[MemberRoots],
  diagnostics_collector: &PublishDiagnosticsCollector,
) -> bool {
  let mut seen_diagnostics = HashSet::new();
  let mut seen_modules = HashSet::with_capacity(graph.specifiers_count());
  for package in packages {
    let mut pending = VecDeque::new();
    for export in &package.exports {
      if seen_modules.insert(export.clone()) {
        pending.push_back(export.clone());
      }
    }

    'analyze_package: while let Some(specifier) = pending.pop_front() {
      let Ok(Some(module)) = graph.try_get_prefer_types(&specifier) else {
        continue;
      };
      let Some(esm_module) = module.esm() else {
        continue;
      };
      if let Some(diagnostic) = esm_module.fast_check_diagnostic() {
        for diagnostic in diagnostic.flatten_multiple() {
          if !seen_diagnostics.insert(diagnostic.message_with_range_for_test())
          {
            continue;
          }
          diagnostics_collector
            .push(PublishDiagnostic::FastCheck(diagnostic.clone()));
          if matches!(
            diagnostic,
            FastCheckDiagnostic::UnsupportedJavaScriptEntrypoint { .. }
          ) {
            break 'analyze_package; // no need to keep analyzing this package
          }
        }
      }

      // analyze the next dependencies
      for dep in esm_module.dependencies_prefer_fast_check().values() {
        let Some(specifier) = graph.resolve_dependency_from_dep(dep, true)
        else {
          continue;
        };

        let dep_in_same_package =
          specifier.as_str().starts_with(package.dir_url.as_str());
        if dep_in_same_package {
          let is_new = seen_modules.insert(specifier.clone());
          if is_new {
            pending.push_back(specifier.clone());
          }
        }
      }
    }
  }

  !seen_diagnostics.is_empty()
}