---@diagnostic disable: duplicate-set-field, need-check-nil, param-type-mismatch, assign-type-mismatch, redundant-parameter
local highlight = require 'bugabinga.pivi.highlight'
local render = require 'bugabinga.pivi.render'
local entry = require 'bugabinga.pivi.entry'
local transcript = require 'bugabinga.pivi.transcript'
local fake = dofile 'tests/helpers/pivi_fake.lua'

local of = function( name )
  return vim.api.nvim_get_hl( 0, { name = name, link = false, } )
end

local block = function( bufnr, kind, meta, lines )
  local id = entry.open( bufnr, kind, meta )
  for _, text in ipairs( lines ) do entry.line( bufnr, id, text ) end
  entry.close( bufnr, id )
  render.decorate( bufnr, id )
  return id
end

--- Every line highlight applied inside an entry, keyed by line.
local lines_of = function( bufnr )
  local found = {}
  for _, mark in ipairs( render.marks( bufnr ) ) do
    local group = ( mark[4] or {} ).line_hl_group
    if group then found[mark[2] + 1] = group end
  end
  return found
end

local texts_of = function( bufnr )
  local found = {}
  for _, mark in ipairs( render.marks( bufnr ) ) do
    local details = mark[4] or {}
    for _, chunk in ipairs( details.virt_text or {} ) do
      table.insert( found, chunk[2] )
    end
    for _, virtual in ipairs( details.virt_lines or {} ) do
      for _, chunk in ipairs( virtual ) do table.insert( found, chunk[2] ) end
    end
  end
  return found
end

describe( 'pivi highlight', function()
  local bufnr

  before_each( function()
    bufnr = transcript.ensure 'coloured'
    transcript.clear( bufnr )
  end )

  after_each( function()
    transcript.forget_all()
    fake.close_extra_windows()
  end )

  it( 'defines a group for every role', function()
    for _, name in ipairs( highlight.names() ) do
      assert.is_true( next( of( name ) ) ~= nil, name .. ' has no colour' )
    end
  end )

  it( 'leaves a colour scheme in charge', function()
    vim.api.nvim_set_hl( 0, 'PiviUser', { bg = '#123456', } )

    highlight.apply()

    assert.equal( tonumber( '123456', 16 ), of( 'PiviUser' ).bg )
  end )

  it( 'makes a user message the only one with a background', function()
    local prompt = block( bufnr, 'prompt', { text = 'find me', }, { 'find me', } )
    local answer = block( bufnr, 'answer', {}, { 'an answer', 'over two lines', } )
    local tool = block( bufnr, 'tool', { tool = 'read', }, { 'read a.lua', } )

    local applied = lines_of( bufnr )
    local first = select( 1, entry.range( bufnr, prompt ) )
    local answered = select( 1, entry.range( bufnr, answer ) )
    local worked = select( 1, entry.range( bufnr, tool ) )

    assert.equal( 'PiviUser', applied[first] )
    assert.is_nil( applied[answered] )
    assert.equal( 'PiviTool', applied[worked] )

    -- The background is what makes it findable, so it must actually be one.
    assert.is_truthy( of( 'PiviUser' ).bg )
    assert.is_nil( of( 'PiviTool' ).bg )
  end )

  it( 'carries the user background across every line of the message', function()
    local prompt = block( bufnr, 'prompt', { text = 'two lines', }, { 'first', 'second', } )
    local first, last = entry.range( bufnr, prompt )
    local applied = lines_of( bufnr )

    for row = first, last do
      assert.equal( 'PiviUser', applied[row], ( 'line %d is not marked' ):format( row ) )
    end
  end )

  it( 'gives each role its own labelling', function()
    block( bufnr, 'prompt', { text = 'a', }, { 'a', } )
    block( bufnr, 'answer', {}, { 'b', } )
    block( bufnr, 'tool', { tool = 'read', }, { 'read a.lua', } )

    local used = {}
    for _, group in ipairs( texts_of( bufnr ) ) do used[group] = true end

    assert.is_true( used.PiviUserLabel )
    assert.is_true( used.PiviUserBar )
    assert.is_true( used.PiviAssistantLabel )
    assert.is_true( used.PiviToolIcon )
  end )

  it( 'keeps tool work quieter than an answer', function()
    -- An answer is ordinary buffer text; tool output is deliberately dimmed.
    local answer = block( bufnr, 'answer', {}, { 'an answer', } )
    local applied = lines_of( bufnr )

    assert.is_nil( applied[select( 1, entry.range( bufnr, answer ) )] )
    assert.is_truthy( of( 'PiviTool' ).fg )
  end )

  it( 'marks a failure without borrowing the tool colour', function()
    local failed = block( bufnr, 'error', { error = 'boom', }, { 'boom', } )
    local applied = lines_of( bufnr )

    assert.equal( 'PiviError', applied[select( 1, entry.range( bufnr, failed ) )] )
  end )
end )