local mod = require 'std.dbg.file'
local encode = require 'std.dbg.encode'
local write_event = mod.write
local read_all = mod.read_all
local read_new = mod.read_new
local get_context = mod.get_context
local get_path = mod.get_path
local close_fd = mod.close_fd

describe('std.dbg.file', function()
  describe('get_path()', function()
    it('should return a string path', function()
      local result = get_path()
      assert.is_string(result)
      assert.is_not_nil(result:match 'bugabinga_config_debug.jsonl')
    end)
  end)

  describe('get_context()', function()
    it('should return filename, function_name, and line_number', function()
      local filename, fn_name, line = get_context()
      assert.is_string(filename)
      assert.is_string(fn_name)
      assert.is_number(line)
    end)

    it('should return three values (types)', function()
      local filename, fn_name, line = get_context()
      assert.is_string(filename)
      assert.is_string(fn_name)
      assert.is_number(line)
    end)

    it('should skip std.dbg internal frames', function()
      local filename, fn_name, line = get_context()
      assert.is_nil(filename:match 'std/dbg/file%.lua')
    end)
  end)

  describe('write() and read_all() integration', function()
    local test_file

    before_each(function()
      mod.clear_log()
      test_file = vim.fn.stdpath 'state' .. '/test_debug_spec.jsonl'
      vim.fn.delete(test_file)
    end)

    after_each(function()
      vim.fn.delete(test_file)
    end)

    it('should write an event and read it back', function()
      local event = {
        kind = 'DEBUG',
        date = os.time(),
        format = 'test {val}',
        data = { val = 123 },
        filename = '/test/file.lua',
        fn = 'test_fn',
        line = 42,
      }
      write_event(event, test_file)
      local events = read_all(test_file)
      assert.equal(1, #events)
      assert.equal('DEBUG', events[1].kind)
      assert.equal(42, events[1].line)
    end)

    it('should write multiple events, each on its own line', function()
      local event1 = {
        kind = 'DEBUG',
        date = os.time(),
        format = 'first',
        data = {},
        filename = '/a.lua',
        fn = 'f',
        line = 1,
      }
      local event2 = {
        kind = 'ERROR',
        date = os.time(),
        format = 'second',
        data = {},
        filename = '/b.lua',
        fn = 'g',
        line = 2,
      }
      write_event(event1, test_file)
      write_event(event2, test_file)
      local events = read_all(test_file)
      assert.equal(2, #events)
      assert.equal('DEBUG', events[1].kind)
      assert.equal('ERROR', events[2].kind)
    end)

    it('should append, not overwrite', function()
      local event1 = { kind = 'DEBUG', date = os.time(), format = 'a', data = {}, filename = '/a', fn = 'f', line = 1 }
      local event2 = { kind = 'TRACE', date = os.time(), format = 'b', data = {}, filename = '/b', fn = 'g', line = 2 }
      write_event(event1, test_file)
      write_event(event2, test_file)
      local events = read_all(test_file)
      assert.equal(2, #events)
    end)

    it('should return empty list when file does not exist', function()
      local events = read_all('/nonexistent/path/that/does/not/exist.jsonl')
      assert.equal(0, #events)
    end)

    it('should reopen fd when file is externally recreated', function()
      close_fd()
      vim.fn.delete(get_path())
      local event1 = { kind = 'DEBUG', date = os.time(), message = 'e1', data = {}, filename = '/a.lua', fn = 'f', line = 1 }
      local event2 = { kind = 'ERROR', date = os.time(), message = 'e2', data = {}, filename = '/b.lua', fn = 'g', line = 2 }
      write_event(event1)
      vim.fn.delete(get_path())
      write_event(event2)
      local events = read_all(get_path())
      assert.equal(1, #events, 'new writes go to newly created file after deletion')
      assert.equal('e2', events[1].message)
    end)

    it('should handle events with nested data', function()
      local event = {
        kind = 'ERROR',
        date = os.time(),
        format = 'nested {data}',
        data = { { a = 1 }, { b = 2 } },
        filename = '/c.lua',
        fn = 'h',
        line = 99,
      }
      write_event(event, test_file)
      local events = read_all(test_file)
      assert.equal(1, #events)
      assert.equal(1, events[1].data[1].a)
      assert.equal(2, events[1].data[2].b)
    end)

    it('should store date as os.time() integer', function()
      local before = os.time()
      local event = {
        kind = 'DEBUG',
        date = os.time(),
        format = 'time test',
        data = {},
        filename = '/t.lua',
        fn = 't',
        line = 1,
      }
      write_event(event, test_file)
      local after = os.time()
      local events = read_all(test_file)
      assert.is_number(events[1].date)
      assert.is_true(events[1].date >= before)
      assert.is_true(events[1].date <= after)
    end)
  end)

  describe('read_new()', function()
    local test_file

    before_each(function()
      test_file = vim.fn.stdpath 'state' .. '/test_read_new_spec.jsonl'
      vim.fn.delete(test_file)
      close_fd()
    end)

    after_each(function()
      vim.fn.delete(test_file)
    end)

    it('should return only events after last_count', function()
      for i = 1, 5 do
        write_event({ kind = 'DEBUG', date = os.time(), message = 'event ' .. i, data = {}, filename = '/t.lua', fn = 'f', line = 1 }, test_file)
      end
      local new_events, total = read_new(3, test_file)
      assert.equal(2, #new_events)
      assert.equal(5, total)
      assert.equal('event 4', new_events[1].message)
      assert.equal('event 5', new_events[2].message)
    end)

    it('should return all events when last_count is 0', function()
      for i = 1, 3 do
        write_event({ kind = 'DEBUG', date = os.time(), message = 'e' .. i, data = {}, filename = '/t.lua', fn = 'f', line = 1 }, test_file)
      end
      local new_events, total = read_new(0, test_file)
      assert.equal(3, #new_events)
      assert.equal(3, total)
    end)

    it('should return empty when last_count equals total events', function()
      for i = 1, 3 do
        write_event({ kind = 'DEBUG', date = os.time(), message = 'e' .. i, data = {}, filename = '/t.lua', fn = 'f', line = 1 }, test_file)
      end
      local new_events, total = read_new(3, test_file)
      assert.equal(0, #new_events)
      assert.equal(3, total)
    end)

    it('should return empty and 0 when file does not exist', function()
      local new_events, total = read_new(0, '/nonexistent/path.jsonl')
      assert.equal(0, #new_events)
      assert.equal(0, total)
    end)
  end)
end)