-- Plan9 colorscheme for Neovim
-- Authentic Plan 9 / Acme colors from plan9port and 9front source
-- All colors derived from libdraw constants and acme/rio/sam source code
-- Syntax highlighting uses only the Plan 9 system palette

local M = {}

-- Authentic Plan 9 palette (from draw.h / libdraw)
local p9 = {
  black         = "#000000", -- DBlack
  white         = "#ffffff", -- DWhite
  red           = "#ff0000", -- DRed
  green         = "#00ff00", -- DGreen
  blue          = "#0000ff", -- DBlue
  cyan          = "#00ffff", -- DCyan
  magenta       = "#ff00ff", -- DMagenta
  yellow        = "#ffff00", -- DYellow
  paleyellow    = "#ffffaa", -- DPaleyellow
  darkyellow    = "#eeee9e", -- DDarkyellow
  darkgreen     = "#448844", -- DDarkgreen
  palegreen     = "#aaffaa", -- DPalegreen
  medgreen      = "#88cc88", -- DMedgreen
  darkblue      = "#000055", -- DDarkblue
  palebluegreen = "#aaffff", -- DPalebluegreen
  paleblue      = "#0000bb", -- DPaleblue
  bluegreen     = "#008888", -- DBluegreen
  greygreen     = "#55aaaa", -- DGreygreen
  palegreygreen = "#9eeeee", -- DPalegreygreen
  yellowgreen   = "#99994c", -- DYellowgreen
  medblue       = "#000099", -- DMedblue
  greyblue      = "#005dbb", -- DGreyblue
  palegreyblue  = "#4993dd", -- DPalegreyblue
  purpleblue    = "#8888cc", -- DPurpleblue

  -- Acme computed mixes (allocimagemix)
  acme_body     = "#ffffea", -- DPaleyellow + DWhite mix (acme text bg)
  acme_tag      = "#eaffff", -- DPalebluegreen + DWhite mix (acme tag bg)

  -- Acme UI specific
  b2_red        = "#aa0000", -- Mouse button 2 (execute)
  b3_green      = "#006600", -- Mouse button 3 (look/plumb)
  scroll        = "#444444", -- Sam scroll indicator
  pale_text     = "#666666", -- Rio inactive text
  rio_bg        = "#777777", -- Rio desktop
  rio_inactive  = "#999999", -- Rio inactive border
}

local colors = {
  -- Editor base (Acme body)
  bg            = p9.acme_body,
  bg_dim        = p9.darkyellow,
  bg_dark       = p9.yellowgreen,
  fg            = p9.black,
  fg_dim        = p9.pale_text,
  fg_faint      = p9.rio_inactive,

  -- Acme tag bar
  tagbar        = p9.acme_tag,
  tag_sel       = p9.palegreygreen,
  tag_border    = p9.purpleblue,

  -- Selection (Acme body selection)
  selection     = p9.darkyellow,
  cursor_line   = "#f5f5d5",

  -- Borders
  border        = p9.yellowgreen,

  -- Syntax (using only Plan 9 system colors)
  comment       = p9.yellowgreen,
  string        = p9.b2_red,
  keyword       = p9.medblue,
  func          = p9.bluegreen,
  type          = p9.darkgreen,
  const         = p9.darkblue,
  preproc       = p9.greyblue,
  special       = p9.purpleblue,
  operator      = p9.scroll,

  -- Diagnostics / semantic (Plan 9 UI colors)
  error         = p9.b2_red,
  warn          = p9.yellowgreen,
  info          = p9.darkgreen,
  hint          = p9.bluegreen,

  -- Git (semantic using Plan 9 palette)
  git_add       = p9.darkgreen,
  git_change    = p9.yellowgreen,
  git_delete    = p9.b2_red,

  -- Diff backgrounds (pale versions)
  diff_add      = p9.palegreen,
  diff_delete   = "#ffaaaa",
  diff_change   = p9.darkyellow,
  diff_text     = p9.yellowgreen,

  -- Line numbers
  line_nr       = p9.rio_inactive,

  -- Modified indicator
  modified      = p9.medblue,
}

function M.setup()
  vim.cmd("hi clear")
  if vim.fn.exists("syntax_on") then
    vim.cmd("syntax reset")
  end

  vim.o.background = "light"
  vim.g.colors_name = "plan9"

  local hi = function(group, opts)
    vim.api.nvim_set_hl(0, group, opts)
  end

  -- Editor
  hi("Normal", { fg = colors.fg, bg = colors.bg })
  hi("NormalFloat", { fg = colors.fg, bg = p9.acme_tag })
  hi("FloatBorder", { fg = colors.tag_border, bg = p9.acme_tag })
  hi("Cursor", { fg = colors.bg, bg = colors.fg })
  hi("CursorLine", { bg = colors.cursor_line })
  hi("CursorLineNr", { fg = colors.fg, bg = colors.cursor_line, bold = true })
  hi("CursorColumn", { bg = colors.cursor_line })
  hi("LineNr", { fg = colors.line_nr })
  hi("SignColumn", { bg = colors.bg })
  hi("ColorColumn", { bg = colors.bg_dim })
  hi("VertSplit", { fg = colors.border })
  hi("WinSeparator", { fg = colors.border })
  hi("Folded", { fg = colors.fg_dim, bg = colors.bg_dim })
  hi("FoldColumn", { fg = colors.line_nr, bg = colors.bg })
  hi("NonText", { fg = colors.border })
  hi("SpecialKey", { fg = colors.border })
  hi("EndOfBuffer", { fg = colors.bg_dim })
  hi("MatchParen", { fg = colors.fg, bg = p9.palegreygreen, bold = true })
  hi("Directory", { fg = colors.func, bold = true })
  hi("Title", { fg = colors.keyword, bold = true })
  hi("Conceal", { fg = colors.fg_dim })

  -- Selection
  hi("Visual", { bg = colors.selection })
  hi("VisualNOS", { bg = colors.selection })

  -- Search
  hi("Search", { fg = colors.fg, bg = colors.selection })
  hi("IncSearch", { fg = p9.white, bg = colors.keyword })
  hi("CurSearch", { fg = p9.white, bg = colors.keyword })

  -- Spell
  hi("SpellBad", { undercurl = true, sp = colors.error })
  hi("SpellCap", { undercurl = true, sp = colors.info })
  hi("SpellRare", { undercurl = true, sp = colors.hint })
  hi("SpellLocal", { undercurl = true, sp = colors.warn })

  -- Statusline (Acme tag bar style)
  hi("StatusLine", { fg = colors.fg, bg = colors.tagbar, bold = true })
  hi("StatusLineNC", { fg = colors.fg_dim, bg = colors.tagbar })
  hi("TabLine", { fg = colors.fg_dim, bg = colors.tagbar })
  hi("TabLineFill", { bg = colors.tagbar })
  hi("TabLineSel", { fg = colors.fg, bg = colors.bg, bold = true })
  hi("WinBar", { fg = colors.fg, bg = colors.bg })
  hi("WinBarNC", { fg = colors.fg_dim, bg = colors.bg_dim })

  -- Popup menu (Acme tag bar colors)
  hi("Pmenu", { fg = colors.fg, bg = colors.tagbar })
  hi("PmenuSel", { fg = colors.fg, bg = colors.tag_sel, bold = true })
  hi("PmenuSbar", { bg = colors.tagbar })
  hi("PmenuThumb", { bg = colors.tag_border })

  -- Messages
  hi("ErrorMsg", { fg = colors.error, bold = true })
  hi("WarningMsg", { fg = colors.warn, bold = true })
  hi("ModeMsg", { fg = colors.fg, bold = true })
  hi("MoreMsg", { fg = colors.info, bold = true })
  hi("Question", { fg = colors.info })

  -- Diagnostics
  hi("DiagnosticError", { fg = colors.error })
  hi("DiagnosticWarn", { fg = colors.warn })
  hi("DiagnosticInfo", { fg = colors.info })
  hi("DiagnosticHint", { fg = colors.hint })
  hi("DiagnosticUnderlineError", { undercurl = true, sp = colors.error })
  hi("DiagnosticUnderlineWarn", { undercurl = true, sp = colors.warn })
  hi("DiagnosticUnderlineInfo", { undercurl = true, sp = colors.info })
  hi("DiagnosticUnderlineHint", { undercurl = true, sp = colors.hint })

  -- Diff
  hi("DiffAdd", { bg = colors.diff_add })
  hi("DiffDelete", { bg = colors.diff_delete })
  hi("DiffChange", { bg = colors.diff_change })
  hi("DiffText", { bg = colors.diff_text })

  -- Syntax (Plan 9 palette — muted, deliberate color choices)
  hi("Comment", { fg = colors.comment, italic = true })
  hi("Constant", { fg = colors.const })
  hi("String", { fg = colors.string })
  hi("Character", { fg = colors.string })
  hi("Number", { fg = colors.const })
  hi("Boolean", { fg = colors.const })
  hi("Float", { fg = colors.const })
  hi("Identifier", { fg = colors.fg })
  hi("Function", { fg = colors.func })
  hi("Statement", { fg = colors.keyword })
  hi("Conditional", { fg = colors.keyword })
  hi("Repeat", { fg = colors.keyword })
  hi("Label", { fg = colors.keyword })
  hi("Operator", { fg = colors.operator })
  hi("Keyword", { fg = colors.keyword, bold = true })
  hi("Exception", { fg = colors.error })
  hi("PreProc", { fg = colors.preproc })
  hi("Include", { fg = colors.preproc })
  hi("Define", { fg = colors.preproc })
  hi("Macro", { fg = colors.preproc })
  hi("PreCondit", { fg = colors.preproc })
  hi("Type", { fg = colors.type })
  hi("StorageClass", { fg = colors.type })
  hi("Structure", { fg = colors.type })
  hi("Typedef", { fg = colors.type })
  hi("Special", { fg = colors.special })
  hi("SpecialChar", { fg = colors.special })
  hi("Tag", { fg = colors.func })
  hi("Delimiter", { fg = colors.operator })
  hi("SpecialComment", { fg = colors.comment, bold = true })
  hi("Debug", { fg = colors.error })
  hi("Underlined", { fg = colors.preproc, underline = true })
  hi("Ignore", { fg = colors.fg_faint })
  hi("Error", { fg = p9.white, bg = colors.error, bold = true })
  hi("Todo", { fg = colors.bg, bg = colors.modified, bold = true })

  -- Treesitter
  hi("@variable", { fg = colors.fg })
  hi("@variable.builtin", { fg = colors.special })
  hi("@variable.parameter", { fg = colors.fg })
  hi("@variable.member", { fg = colors.fg })
  hi("@constant", { fg = colors.const })
  hi("@constant.builtin", { fg = colors.const, bold = true })
  hi("@module", { fg = colors.type })
  hi("@label", { fg = colors.keyword })
  hi("@string", { fg = colors.string })
  hi("@string.documentation", { fg = colors.comment })
  hi("@string.escape", { fg = colors.special })
  hi("@string.special", { fg = colors.special })
  hi("@character", { fg = colors.string })
  hi("@number", { fg = colors.const })
  hi("@boolean", { fg = colors.const, bold = true })
  hi("@float", { fg = colors.const })
  hi("@function", { fg = colors.func })
  hi("@function.builtin", { fg = colors.func })
  hi("@function.call", { fg = colors.func })
  hi("@function.macro", { fg = colors.preproc })
  hi("@method", { fg = colors.func })
  hi("@method.call", { fg = colors.func })
  hi("@constructor", { fg = colors.type })
  hi("@parameter", { fg = colors.fg })
  hi("@keyword", { fg = colors.keyword, bold = true })
  hi("@keyword.function", { fg = colors.keyword, bold = true })
  hi("@keyword.operator", { fg = colors.keyword })
  hi("@keyword.return", { fg = colors.keyword, bold = true })
  hi("@conditional", { fg = colors.keyword })
  hi("@repeat", { fg = colors.keyword })
  hi("@exception", { fg = colors.error })
  hi("@include", { fg = colors.preproc })
  hi("@type", { fg = colors.type })
  hi("@type.builtin", { fg = colors.type })
  hi("@type.qualifier", { fg = colors.keyword })
  hi("@type.definition", { fg = colors.type })
  hi("@storageclass", { fg = colors.keyword })
  hi("@attribute", { fg = colors.preproc })
  hi("@field", { fg = colors.fg })
  hi("@property", { fg = colors.fg })
  hi("@punctuation.bracket", { fg = colors.operator })
  hi("@punctuation.delimiter", { fg = colors.operator })
  hi("@punctuation.special", { fg = colors.special })
  hi("@comment", { fg = colors.comment, italic = true })
  hi("@tag", { fg = colors.func })
  hi("@tag.attribute", { fg = colors.type })
  hi("@tag.delimiter", { fg = colors.operator })
  hi("@text", { fg = colors.fg })
  hi("@text.strong", { bold = true })
  hi("@text.emphasis", { italic = true })
  hi("@text.underline", { underline = true })
  hi("@text.strike", { strikethrough = true })
  hi("@text.title", { fg = colors.keyword, bold = true })
  hi("@text.literal", { fg = colors.string })
  hi("@text.uri", { fg = colors.preproc, underline = true })
  hi("@text.todo", { fg = colors.bg, bg = colors.modified, bold = true })
  hi("@text.note", { fg = colors.bg, bg = colors.info, bold = true })
  hi("@text.warning", { fg = colors.bg, bg = colors.warn, bold = true })
  hi("@text.danger", { fg = p9.white, bg = colors.error, bold = true })

  -- LSP
  hi("LspReferenceText", { bg = colors.selection })
  hi("LspReferenceRead", { bg = colors.selection })
  hi("LspReferenceWrite", { bg = colors.selection })
  hi("LspSignatureActiveParameter", { fg = colors.keyword, bold = true })

  -- Git signs
  hi("GitSignsAdd", { fg = colors.git_add })
  hi("GitSignsChange", { fg = colors.git_change })
  hi("GitSignsDelete", { fg = colors.git_delete })
  hi("GitSignsCurrentLineBlame", { fg = colors.fg_faint, italic = true })

  -- Telescope / Snacks picker
  hi("TelescopeBorder", { fg = colors.tag_border })
  hi("TelescopePromptBorder", { fg = colors.tag_border })
  hi("TelescopeResultsBorder", { fg = colors.tag_border })
  hi("TelescopePreviewBorder", { fg = colors.tag_border })
  hi("TelescopeSelection", { bg = colors.selection })
  hi("TelescopeSelectionCaret", { fg = colors.keyword, bg = colors.selection })
  hi("TelescopeMatching", { fg = colors.string, bold = true })

  -- NeoTree (sidebar like Acme tag column)
  hi("NeoTreeNormal", { fg = colors.fg, bg = colors.tagbar })
  hi("NeoTreeNormalNC", { fg = colors.fg, bg = colors.tagbar })
  hi("NeoTreeDirectoryName", { fg = colors.fg, bold = true })
  hi("NeoTreeDirectoryIcon", { fg = colors.func })
  hi("NeoTreeRootName", { fg = colors.fg, bold = true })
  hi("NeoTreeFileName", { fg = colors.fg })
  hi("NeoTreeGitAdded", { fg = colors.git_add })
  hi("NeoTreeGitModified", { fg = colors.git_change })
  hi("NeoTreeGitDeleted", { fg = colors.git_delete })

  -- Which-key
  hi("WhichKey", { fg = colors.keyword, bold = true })
  hi("WhichKeyGroup", { fg = colors.func })
  hi("WhichKeyDesc", { fg = colors.fg })
  hi("WhichKeySeparator", { fg = colors.fg_faint })
  hi("WhichKeyFloat", { bg = colors.tagbar })

  -- Indent blankline
  hi("IndentBlanklineChar", { fg = colors.bg_dim })
  hi("IndentBlanklineContextChar", { fg = colors.border })
  hi("IblIndent", { fg = colors.bg_dim })
  hi("IblScope", { fg = colors.border })

  -- Notify
  hi("NotifyERRORBorder", { fg = colors.error })
  hi("NotifyWARNBorder", { fg = colors.warn })
  hi("NotifyINFOBorder", { fg = colors.info })
  hi("NotifyDEBUGBorder", { fg = colors.fg_faint })
  hi("NotifyTRACEBorder", { fg = colors.hint })
  hi("NotifyERRORIcon", { fg = colors.error })
  hi("NotifyWARNIcon", { fg = colors.warn })
  hi("NotifyINFOIcon", { fg = colors.info })
  hi("NotifyDEBUGIcon", { fg = colors.fg_faint })
  hi("NotifyTRACEIcon", { fg = colors.hint })
  hi("NotifyERRORTitle", { fg = colors.error })
  hi("NotifyWARNTitle", { fg = colors.warn })
  hi("NotifyINFOTitle", { fg = colors.info })
  hi("NotifyDEBUGTitle", { fg = colors.fg_faint })
  hi("NotifyTRACETitle", { fg = colors.hint })

  -- Snacks (LazyVim notifications/dashboard)
  hi("SnacksNotifierBorderError", { fg = colors.error })
  hi("SnacksNotifierBorderWarn", { fg = colors.warn })
  hi("SnacksNotifierBorderInfo", { fg = colors.info })
  hi("SnacksNotifierBorderDebug", { fg = colors.fg_faint })
  hi("SnacksNotifierBorderTrace", { fg = colors.hint })
  hi("SnacksDashboardHeader", { fg = colors.keyword, bold = true })
  hi("SnacksDashboardKey", { fg = colors.keyword, bold = true })
  hi("SnacksDashboardIcon", { fg = colors.func })
  hi("SnacksDashboardDesc", { fg = colors.fg })
  hi("SnacksDashboardFooter", { fg = colors.fg_dim })

  -- Dashboard (legacy)
  hi("DashboardHeader", { fg = colors.keyword, bold = true })
  hi("DashboardCenter", { fg = colors.fg })
  hi("DashboardFooter", { fg = colors.fg_faint })
  hi("DashboardShortCut", { fg = colors.keyword })

  -- Lazy
  hi("LazyButton", { fg = colors.fg, bg = colors.bg_dim })
  hi("LazyButtonActive", { fg = colors.fg, bg = colors.tag_sel, bold = true })
  hi("LazyH1", { fg = colors.keyword, bold = true })
  hi("LazySpecial", { fg = colors.func })

  -- Mini statusline (Plan 9 accent colors for modes)
  hi("MiniStatuslineModeNormal", { fg = p9.white, bg = p9.bluegreen, bold = true })
  hi("MiniStatuslineModeInsert", { fg = p9.white, bg = p9.darkgreen, bold = true })
  hi("MiniStatuslineModeVisual", { fg = p9.white, bg = p9.purpleblue, bold = true })
  hi("MiniStatuslineModeReplace", { fg = p9.white, bg = p9.b2_red, bold = true })
  hi("MiniStatuslineModeCommand", { fg = colors.fg, bg = p9.darkyellow, bold = true })

  -- Bufferline (tag bar style)
  hi("BufferLineFill", { bg = colors.tagbar })
  hi("BufferLineBackground", { fg = colors.fg_dim, bg = colors.tagbar })
  hi("BufferLineBuffer", { fg = colors.fg_dim, bg = colors.tagbar })
  hi("BufferLineBufferSelected", { fg = colors.fg, bg = colors.bg, bold = true })
  hi("BufferLineBufferVisible", { fg = colors.fg_dim, bg = colors.tagbar })
  hi("BufferLineCloseButton", { fg = colors.fg_dim, bg = colors.tagbar })
  hi("BufferLineCloseButtonSelected", { fg = colors.error, bg = colors.bg })
  hi("BufferLineCloseButtonVisible", { fg = colors.fg_dim, bg = colors.tagbar })
  hi("BufferLineIndicatorSelected", { fg = colors.tag_border, bg = colors.bg })
  hi("BufferLineModified", { fg = colors.modified, bg = colors.tagbar })
  hi("BufferLineModifiedSelected", { fg = colors.modified, bg = colors.bg })
  hi("BufferLineSeparator", { fg = colors.tagbar, bg = colors.tagbar })
  hi("BufferLineSeparatorSelected", { fg = colors.tagbar, bg = colors.bg })

  -- Copilot
  hi("CopilotSuggestion", { fg = colors.fg_faint })

  -- Lualine (if used instead of mini)
  hi("lualine_a_normal", { fg = p9.white, bg = p9.bluegreen, bold = true })
  hi("lualine_a_insert", { fg = p9.white, bg = p9.darkgreen, bold = true })
  hi("lualine_a_visual", { fg = p9.white, bg = p9.purpleblue, bold = true })
  hi("lualine_a_replace", { fg = p9.white, bg = p9.b2_red, bold = true })
  hi("lualine_a_command", { fg = colors.fg, bg = p9.darkyellow, bold = true })
  hi("lualine_b_normal", { fg = colors.fg, bg = colors.tagbar })
  hi("lualine_c_normal", { fg = colors.fg_dim, bg = colors.bg_dim })
end

M.setup()

return M