// Completion provider for the ƿit LSP.

// CompletionItemKind constants (LSP spec)
def KIND_FUNCTION = 3
def KIND_VARIABLE = 6
def KIND_KEYWORD = 14
def KIND_CONSTANT = 21

// All intrinsic function names
def intrinsic_functions = [
  "abs", "apply", "array", "ceiling", "character", "codepoint",
  "ends_with", "every", "extract", "fallback", "filter", "find",
  "floor", "format", "fraction",
  "is_array", "is_blob", "is_character", "is_data", "is_digit",
  "is_false", "is_fit", "is_function", "is_integer", "is_letter",
  "is_logical", "is_lower", "is_null", "is_number", "is_object",
  "is_pattern", "is_stone", "is_text", "is_true", "is_upper",
  "is_whitespace",
  "length", "logical", "lower", "max", "min", "modulo",
  "neg", "normalize", "not", "number",
  "parallel", "print", "race", "record", "reduce", "remainder",
  "replace", "reverse", "round",
  "search", "sequence", "sign", "some", "sort", "starts_with",
  "stone", "text", "trim", "trunc", "upper", "whole",
  "meme", "proto", "isa", "splat", "use"
]

// Keywords that can be completed
def keywords = [
  "var", "def", "if", "else", "for", "while", "do",
  "function", "return", "go", "break", "continue",
  "disrupt", "disruption", "delete", "in", "this",
  "null", "true", "false"
]

// Actor intrinsics (only in .ce files)
def actor_intrinsics = [
  "$me", "$send", "$start", "$stop", "$delay",
  "$receiver", "$clock", "$portal", "$contact",
  "$couple", "$unneeded", "$connection", "$time_limit"
]

// Walk AST scopes to find variables visible at a position.
var collect_scope_vars = function(doc, line, col) {
  var vars = []
  var ast = doc.ast
  var _i = 0
  var _j = 0
  var scope = null
  var v = null

  if (ast == null || ast.scopes == null) {
    return vars
  }

  // Collect variables from all scopes (simplified: return all declared vars)
  while (_i < length(ast.scopes)) {
    scope = ast.scopes[_i]
    if (scope.vars != null) {
      _j = 0
      while (_j < length(scope.vars)) {
        v = scope.vars[_j]
        if (v.name != null) {
          vars[] = {
            label: v.name,
            kind: (v.is_const == true) ? KIND_CONSTANT : KIND_VARIABLE,
            detail: (v.is_const == true) ? "def" : "var"
          }
        }
        _j = _j + 1
      }
    }
    _i = _i + 1
  }

  return vars
}

// Provide completions for a document at a position.
var complete = function(doc, line, col) {
  var items = []
  var _i = 0
  var is_actor = ends_with(doc.uri, ".ce")

  // Intrinsic functions
  _i = 0
  while (_i < length(intrinsic_functions)) {
    items[] = {
      label: intrinsic_functions[_i],
      kind: KIND_FUNCTION,
      detail: "intrinsic"
    }
    _i = _i + 1
  }

  // Keywords
  _i = 0
  while (_i < length(keywords)) {
    items[] = {
      label: keywords[_i],
      kind: KIND_KEYWORD,
      detail: "keyword"
    }
    _i = _i + 1
  }

  // Actor intrinsics (only for .ce files)
  if (is_actor) {
    _i = 0
    while (_i < length(actor_intrinsics)) {
      items[] = {
        label: actor_intrinsics[_i],
        kind: KIND_FUNCTION,
        detail: "actor intrinsic"
      }
      _i = _i + 1
    }
  }

  // Variables from scope analysis
  var scope_vars = collect_scope_vars(doc, line, col)
  _i = 0
  while (_i < length(scope_vars)) {
    items[] = scope_vars[_i]
    _i = _i + 1
  }

  return items
}

return {
  complete: complete
}