require('spec.helpers')

local config = require('pending.config')

describe('detail frontmatter', function()
  local buffer
  local tmpdir

  before_each(function()
    tmpdir = vim.fn.tempname()
    vim.fn.mkdir(tmpdir, 'p')
    vim.g.pending = { data_path = tmpdir .. '/tasks.json' }
    config.reset()
    package.loaded['pending'] = nil
    package.loaded['pending.buffer'] = nil
    buffer = require('pending.buffer')
  end)

  after_each(function()
    vim.fn.delete(tmpdir, 'rf')
    vim.g.pending = nil
    config.reset()
    package.loaded['pending'] = nil
    package.loaded['pending.buffer'] = nil
  end)

  describe('build_detail_frontmatter', function()
    it('renders status and priority for minimal task', function()
      local lines = buffer._build_detail_frontmatter({
        id = 1,
        description = 'Test',
        status = 'pending',
        priority = 0,
        entry = '',
        modified = '',
        order = 0,
      })
      assert.are.equal(2, #lines)
      assert.are.equal('Status: pending', lines[1])
      assert.are.equal('Priority: 0', lines[2])
    end)

    it('renders all fields', function()
      local lines = buffer._build_detail_frontmatter({
        id = 1,
        description = 'Test',
        status = 'wip',
        priority = 2,
        category = 'Work',
        due = '2026-03-15',
        recur = 'weekly',
        entry = '',
        modified = '',
        order = 0,
      })
      assert.are.equal(5, #lines)
      assert.are.equal('Status: wip', lines[1])
      assert.are.equal('Priority: 2', lines[2])
      assert.are.equal('Category: Work', lines[3])
      assert.are.equal('Due: 2026-03-15', lines[4])
      assert.are.equal('Recur: weekly', lines[5])
    end)

    it('prefixes recur with ! for completion mode', function()
      local lines = buffer._build_detail_frontmatter({
        id = 1,
        description = 'Test',
        status = 'pending',
        priority = 0,
        recur = 'daily',
        recur_mode = 'completion',
        entry = '',
        modified = '',
        order = 0,
      })
      assert.are.equal('Recur: !daily', lines[3])
    end)

    it('omits optional fields when absent', function()
      local lines = buffer._build_detail_frontmatter({
        id = 1,
        description = 'Test',
        status = 'done',
        priority = 1,
        entry = '',
        modified = '',
        order = 0,
      })
      assert.are.equal(2, #lines)
      assert.are.equal('Status: done', lines[1])
      assert.are.equal('Priority: 1', lines[2])
    end)
  end)

  describe('parse_detail_frontmatter', function()
    it('parses minimal frontmatter', function()
      local lines = {
        '# My task',
        'Status: pending',
        'Priority: 0',
        '---',
        'some notes',
      }
      local sep, fields, err = buffer._parse_detail_frontmatter(lines)
      assert.is_nil(err)
      assert.are.equal(4, sep)
      assert.are.equal('My task', fields.description)
      assert.are.equal('pending', fields.status)
      assert.are.equal(0, fields.priority)
    end)

    it('parses all fields', function()
      local lines = {
        '# Fix the bug',
        'Status: wip',
        'Priority: 2',
        'Category: Work',
        'Due: 2026-03-15',
        'Recur: weekly',
        '---',
      }
      local sep, fields, err = buffer._parse_detail_frontmatter(lines)
      assert.is_nil(err)
      assert.are.equal(7, sep)
      assert.are.equal('Fix the bug', fields.description)
      assert.are.equal('wip', fields.status)
      assert.are.equal(2, fields.priority)
      assert.are.equal('Work', fields.category)
      assert.are.equal('2026-03-15', fields.due)
      assert.are.equal('weekly', fields.recur)
    end)

    it('resolves due date keywords', function()
      local lines = {
        '# Task',
        'Status: pending',
        'Priority: 0',
        'Due: tomorrow',
        '---',
      }
      local _, fields, err = buffer._parse_detail_frontmatter(lines)
      assert.is_nil(err)
      local today = os.date('*t') --[[@as osdate]]
      local expected = os.date(
        '%Y-%m-%d',
        os.time({ year = today.year, month = today.month, day = today.day + 1 })
      )
      assert.are.equal(expected, fields.due)
    end)

    it('parses completion-mode recurrence', function()
      local lines = {
        '# Task',
        'Status: pending',
        'Priority: 0',
        'Recur: !daily',
        '---',
      }
      local _, fields, err = buffer._parse_detail_frontmatter(lines)
      assert.is_nil(err)
      assert.are.equal('daily', fields.recur)
      assert.are.equal('completion', fields.recur_mode)
    end)

    it('clears optional fields when lines removed', function()
      local lines = {
        '# Task',
        'Status: done',
        'Priority: 1',
        '---',
      }
      local _, fields, err = buffer._parse_detail_frontmatter(lines)
      assert.is_nil(err)
      assert.are.equal(vim.NIL, fields.category)
      assert.are.equal(vim.NIL, fields.due)
      assert.are.equal(vim.NIL, fields.recur)
    end)

    it('skips blank lines in frontmatter', function()
      local lines = {
        '# Task',
        'Status: pending',
        '',
        'Priority: 0',
        '---',
      }
      local _, fields, err = buffer._parse_detail_frontmatter(lines)
      assert.is_nil(err)
      assert.are.equal('pending', fields.status)
      assert.are.equal(0, fields.priority)
    end)

    it('errors on missing separator', function()
      local lines = {
        '# Task',
        'Status: pending',
        'Priority: 0',
      }
      local _, _, err = buffer._parse_detail_frontmatter(lines)
      assert.truthy(err:find('missing separator'))
    end)

    it('errors on missing title', function()
      local lines = {
        '',
        'Status: pending',
        '---',
      }
      local _, _, err = buffer._parse_detail_frontmatter(lines)
      assert.truthy(err:find('missing or empty title'))
    end)

    it('errors on empty title', function()
      local lines = {
        '#   ',
        'Status: pending',
        '---',
      }
      local _, _, err = buffer._parse_detail_frontmatter(lines)
      assert.truthy(err:find('missing or empty title'))
    end)

    it('errors on invalid status', function()
      local lines = {
        '# Task',
        'Status: bogus',
        'Priority: 0',
        '---',
      }
      local _, _, err = buffer._parse_detail_frontmatter(lines)
      assert.truthy(err:find('invalid status'))
    end)

    it('errors on negative priority', function()
      local lines = {
        '# Task',
        'Status: pending',
        'Priority: -1',
        '---',
      }
      local _, _, err = buffer._parse_detail_frontmatter(lines)
      assert.truthy(err:find('invalid priority'))
    end)

    it('errors on non-integer priority', function()
      local lines = {
        '# Task',
        'Status: pending',
        'Priority: 1.5',
        '---',
      }
      local _, _, err = buffer._parse_detail_frontmatter(lines)
      assert.truthy(err:find('invalid priority'))
    end)

    it('errors on priority exceeding max', function()
      local lines = {
        '# Task',
        'Status: pending',
        'Priority: 4',
        '---',
      }
      local _, _, err = buffer._parse_detail_frontmatter(lines)
      assert.truthy(err:find('max is 3'))
    end)

    it('errors on invalid due date', function()
      local lines = {
        '# Task',
        'Status: pending',
        'Priority: 0',
        'Due: notadate',
        '---',
      }
      local _, _, err = buffer._parse_detail_frontmatter(lines)
      assert.truthy(err:find('invalid due date'))
    end)

    it('errors on empty due value', function()
      local lines = {
        '# Task',
        'Due: ',
        '---',
      }
      local _, _, err = buffer._parse_detail_frontmatter(lines)
      assert.truthy(err:find('empty due value'))
    end)

    it('errors on invalid recurrence', function()
      local lines = {
        '# Task',
        'Recur: nope',
        '---',
      }
      local _, _, err = buffer._parse_detail_frontmatter(lines)
      assert.truthy(err:find('invalid recurrence'))
    end)

    it('errors on empty recur value', function()
      local lines = {
        '# Task',
        'Recur: ',
        '---',
      }
      local _, _, err = buffer._parse_detail_frontmatter(lines)
      assert.truthy(err:find('empty recur value'))
    end)

    it('errors on empty category value', function()
      local lines = {
        '# Task',
        'Category: ',
        '---',
      }
      local _, _, err = buffer._parse_detail_frontmatter(lines)
      assert.truthy(err:find('empty category'))
    end)

    it('errors on unknown field', function()
      local lines = {
        '# Task',
        'Status: pending',
        'Foo: bar',
        '---',
      }
      local _, _, err = buffer._parse_detail_frontmatter(lines)
      assert.truthy(err:find('unknown field: foo'))
    end)

    it('errors on duplicate field', function()
      local lines = {
        '# Task',
        'Status: pending',
        'Status: done',
        '---',
      }
      local _, _, err = buffer._parse_detail_frontmatter(lines)
      assert.truthy(err:find('duplicate field'))
    end)

    it('errors on malformed frontmatter line', function()
      local lines = {
        '# Task',
        'not a key value pair',
        '---',
      }
      local _, _, err = buffer._parse_detail_frontmatter(lines)
      assert.truthy(err:find('invalid frontmatter line'))
    end)

    it('is case-insensitive for field keys', function()
      local lines = {
        '# Task',
        'STATUS: wip',
        'PRIORITY: 1',
        'CATEGORY: Work',
        '---',
      }
      local _, fields, err = buffer._parse_detail_frontmatter(lines)
      assert.is_nil(err)
      assert.are.equal('wip', fields.status)
      assert.are.equal(1, fields.priority)
      assert.are.equal('Work', fields.category)
    end)

    it('accepts datetime due format', function()
      local lines = {
        '# Task',
        'Due: 2026-03-15T14:00',
        '---',
      }
      local _, fields, err = buffer._parse_detail_frontmatter(lines)
      assert.is_nil(err)
      assert.are.equal('2026-03-15T14:00', fields.due)
    end)

    it('respects custom max_priority', function()
      vim.g.pending = { data_path = tmpdir .. '/tasks.json', max_priority = 5 }
      config.reset()
      local lines = {
        '# Task',
        'Priority: 5',
        '---',
      }
      local _, fields, err = buffer._parse_detail_frontmatter(lines)
      assert.is_nil(err)
      assert.are.equal(5, fields.priority)
    end)

    it('updates description from title line', function()
      local lines = {
        '# Updated title',
        'Status: pending',
        'Priority: 0',
        '---',
      }
      local _, fields, err = buffer._parse_detail_frontmatter(lines)
      assert.is_nil(err)
      assert.are.equal('Updated title', fields.description)
    end)
  end)
end)