local capture = require 'bugabinga.pivi.capture'

describe( 'pivi capture', function()
  it( 'packs styles into cell-coordinate runs without losing Unicode or whitespace', function()
    local cells = {
      { '界', 1, { foreground = 123, bold = true, }, },
      { '', 1, { foreground = 123, bold = true, }, },
      { 'é', 2, { background = 456, }, },
      { ' ', 2, { background = 456, }, },
    }
    local grid = capture.encode( 4, 2, function( _, col ) return unpack( cells[col] ) end )
    assert.equal( '界é ', grid.rows[1].text )
    assert.same( grid.rows[1], grid.rows[2] )
    assert.same( {
      { col = 1, width = 2, style = '1', },
      { col = 3, width = 2, style = '2', },
    }, grid.rows[1].runs )
    assert.same( { foreground = 123, bold = true, }, grid.styles['1'] )
    assert.same( { background = 456, }, grid.styles['2'] )
    assert.equal( 4, grid.width )
    assert.equal( 2, grid.height )
  end )

  it( 'starts a new run when a style reappears and resets runs per row', function()
    local grid = capture.encode( 3, 2, function( _, col )
      return ' ', col == 2 and 2 or 1, {}
    end )
    assert.equal( 3, #grid.rows[1].runs )
    assert.equal( 1, grid.rows[2].runs[1].col )
    assert.equal( '   ', grid.rows[2].text )
  end )

  it( 'decodes composed UI events identically across arbitrary byte boundaries', function()
    local events = {
      { 'grid_resize', { 1, 4, 2, }, },
      { 'default_colors_set', { 123, 456, 789, 1, 2, }, },
      { 'hl_attr_define', { 1, { foreground = 123, }, { foreground = 7, }, {} }, },
      { 'grid_line', { 1, 0, 0, { { '界', 1, }, { '', }, { 'é', }, { ' ', }, }, false, }, },
      { 'grid_line', { 1, 1, 0, { { 'x', 1, 4, }, }, false, }, },
      { 'grid_cursor_goto', { 1, 0, 2, }, },
      { 'flush', },
    }
    local bytes = vim.mpack.encode( { 2, 'redraw', events, } )
        .. vim.mpack.encode( { 1, 1, vim.NIL, vim.NIL, } )
    local expected = { cells = {}, styles = {}, }
    capture.decode( expected, vim.mpack.Unpacker(), bytes )
    assert.is_true( expected.ready )
    assert.same( { row = 1, col = 3, }, expected.cursor )
    assert.same( { foreground = 7, }, expected.styles[1].cterm )
    assert.equal( 'x', expected.cells[2][4][1] )
    for size = 1, #bytes do
      local state, unpacker = { cells = {}, styles = {}, }, vim.mpack.Unpacker()
      for start = 1, #bytes, size do capture.decode( state, unpacker, bytes:sub( start, start + size - 1 ) ) end
      assert.same( expected, state )
    end
    for seed = 1, 50 do
      local state, unpacker = { cells = {}, styles = {}, }, vim.mpack.Unpacker()
      local offset, value = 1, seed
      while offset <= #bytes do
        value = ( value * 48271 ) % 2147483647
        local size = value % 23 + 1
        capture.decode( state, unpacker, bytes:sub( offset, offset + size - 1 ) )
        offset = offset + size
      end
      assert.same( expected, state )
    end
  end )

  it( 'applies scroll, clear and resize events and reports UI attach errors', function()
    local state = { cells = {}, styles = {}, }
    capture.consume( state, {
      { 'grid_resize', { 1, 2, 2, }, },
      { 'grid_line', { 1, 0, 0, { { 'a', 0, 2, }, }, false, }, },
      { 'grid_line', { 1, 1, 0, { { 'b', 0, 2, }, }, false, }, },
      { 'grid_scroll', { 1, 0, 2, 0, 2, 1, 0, }, },
    } )
    assert.equal( 'b', state.cells[1][1][1] )
    assert.equal( ' ', state.cells[2][1][1] )
    capture.consume( state, { { 'grid_clear', { 1, }, }, } )
    assert.equal( ' ', state.cells[1][1][1] )
    capture.consume( state, { { 'grid_resize', { 1, 1, 1, }, }, } )
    assert.same( { { { ' ', 0, }, }, }, state.cells )
    capture.decode( state, vim.mpack.Unpacker(), vim.mpack.encode( { 1, 1, { 0, 'denied', }, vim.NIL, } ) )
    assert.is_truthy( state.error:find( 'denied', 1, true ) )
  end )

  it( 'refuses to present headless buffer text as a rendered UI', function()
    assert.equal( 0, #vim.api.nvim_list_uis() )
    local result = require( 'bugabinga.pivi.bridge' ).handle { action = 'capture', }
    assert.is_false( result.ok )
    assert.is_truthy( result.error:find( 'attached UI', 1, true ) )
  end )
end )