rust-project.knit

function crateJSON(conf, extra)
  if extra ~= nil then
    for k, v in pairs(extra) do conf[k] = v end
  end
  return f[[{
    "display_name": "$(conf.display_name)",
    "root_module": "$(conf.root_module)",
    "edition": "2021",
    "target": "wasm32-unknown-unknown",
    "is_workspace_member": $(conf.is_workspace_member or false),
    "is_proc_macro": $(conf.is_proc_macro or false),
    "env": {},
    "cfg": [],
    "deps": []
  }]]
end

function normalize(result)
  local formatted = result:gsub("(\n+)", "%1    "):gsub(",\n+%s+$", "")
  return formatted
end

function workspaceMembers() -- workaround because rust-analyzer can't mix rust-project.json and cargo-based project
  local crateConf = {
    is_workspace_member = true,
    is_proc_macro = true,
  }
  function cargoFrom(dirs, conf, recursive)
    local result = ""
    function process(files, depth)
      local list = {}; for i = 1, #dirs do
        for j, path in ipairs(glob(dirs[i]..f"/$files")) do -- I HATE THIS 😢
          if not path:match(dirs[i].."/"..(conf.symlink or "\0")) then
            list[i+j-1] = path
          end
        end
      end
      for _, file in ipairs(list) do
        local name = base(file):gsub("%.rs", "")
        local crate = conf.name
        if crate == nil then
          local root = dir(dir(file)) -- root/[src/*]
          crate = base(root)
          for _ = 2, conf.depth or 2 do
            root = dir(root)
            crate = base(root).."::"..crate
          end
        end
        local module = crate
        if conf.prefix ~= nil then
          module = conf.prefix.."::"..module
        end
        local src = file; for _ = 2, depth do
          src = dir(src)
          module = module.."::"..base(src)
        end
        if not ((name == "lib" and depth == 1) or (name == "mod" and depth > 1)) then
          module = f"$module::$name"
        end
        result = result .. crateJSON({
          display_name = module,
          root_module = file,
        }, crateConf)..",\n  "
      end
    end
    process("src/*.rs", 1)
    process("src/*/*.rs", 2)
    return result
  end
  return normalize(
    cargoFrom({"libs/rust"}, {name="libnusa", symlink="src/types/"}) ..
    cargoFrom(glob("examples/rust/*/*"), {prefix="example", depth=2})
  )
end

function wasmCrates(files)
  local result = ""
  for _, file in ipairs(files) do
    local parent = base(dir(file))
    local name = base(file):gsub("%.rs", "")
    local module = f"wasm::$parent"
    if name ~= "mod" then
      module = module.."::"..name
    end
    result = result .. crateJSON{
      display_name = module,
      root_module = file,
    }..",\n  "
  end
  return normalize(result)
end

-- TODO: set `rust-analyzer.linkedProjects:["./rust-project.json", "./libs/rust/Cargo.toml", "./examples/rust/*/*/Cargo.toml"]` when rust-analyzer support local config
-- https://rust-analyzer.github.io/manual.html#configuration
return function(files)
  local json = f[[{
    "sysroot_src": "$(env.RUST_SRC_PATH)",
    "crates": [
      $(workspaceMembers()),
      $(wasmCrates(files))
    ]
  }]]
  local formatted = json:gsub("(\n+)  ", "%1")
  return formatted
end