-- SPDX-FileCopyrightText: © 2022—2026 Vladimir Zorin <vladimir@deviant.guru>
-- SPDX-License-Identifier: LicenseRef-OWL-1.0-or-later
-- Licensed under OWL v1.0+. See LICENSE.

local std = require("std")
local style = require("term.tss")

local generation = 0
local rss_cache = {}

-- Semantic palette: 26 roles that themes override to change the entire look.
-- Style rules reference these roles; catalog themes only need to redefine this table.
-- The built-in default is the Gruvbox Dark palette.
local default_palette = {
	-- Background tiers
	bg_deep = { 29, 32, 33 }, -- deepest bg, code bg
	bg_mid = { 40, 40, 40 }, -- mid bg, widget items
	bg_surface = { 80, 73, 69 }, -- borders, dividers
	bg_raised = { 102, 92, 84 }, -- raised chrome, line numbers

	-- Foreground tiers (8-level gradient, dimmest to brightest)
	fg1 = { 112, 100, 90 }, -- disabled, faintest
	fg2 = { 124, 111, 100 }, -- dim secondary
	fg3 = { 146, 131, 116 }, -- subdued metadata
	fg4 = { 168, 153, 132 }, -- below-normal
	fg5 = { 189, 174, 147 }, -- normal/body
	fg6 = { 202, 186, 158 }, -- readable
	fg7 = { 213, 196, 161 }, -- strong labels
	fg8 = { 235, 219, 178 }, -- maximum emphasis

	-- Accent colors (4 shades)
	accent1 = { 142, 192, 124 }, -- primary highlight, chrome
	accent2 = { 104, 157, 106 }, -- secondary accent, content
	accent3 = { 131, 165, 152 }, -- tertiary, links, code elements
	accent4 = { 69, 133, 136 }, -- deep/strong accent

	-- Status colors
	success = { 184, 187, 38 }, -- success, enabled, staged
	error = { 251, 73, 52 }, -- error, remove, pipe
	warning = { 250, 189, 47 }, -- warning, dirty, emph
	caution = { 254, 128, 25 }, -- caution, tool names, info

	-- Auxiliary
	special1 = { 177, 98, 134 }, -- purple, decorative
	special2 = { 211, 134, 155 }, -- light purple, mode labels
	warm1 = { 215, 153, 33 }, -- amber, timestamps
	warm2 = { 152, 151, 26 }, -- cocoa/earth brown, separators
	warm3 = { 132, 140, 70 }, -- sage, organic metadata

	-- Canonical text color
	text = { 213, 196, 161 }, -- body text across all sections (== fg7)
}

-- Element overrides applied on top of the palette-derived defaults for the
-- built-in (Gruvbox) theme — colors that don't derive from the palette alone.
local default_overrides = {
	markdown = {
		heading = { fg = { 199, 158, 0 } },
		strong = { fg = { 184, 134, 11 } },
		code_block = { lang = { bg = { 35, 42, 32 } } },
	},
}

-- Compute a dark-tinted background from a status/accent color and a base dark color.
-- Falls back to base for non-RGB values (ANSI color names in terminal theme).
local function dark_tint(color, base)
	if type(color) ~= "table" or type(base) ~= "table" then
		return base
	end
	return {
		math.floor(base[1] * 0.6 + color[1] * 0.1),
		math.floor(base[2] * 0.6 + color[2] * 0.1),
		math.floor(base[3] * 0.6 + color[3] * 0.1),
	}
end

local build_errors = function(p)
	return {
		-- builtin_markdown is used for markdown-formatted error messages in shell
		builtin_markdown = {
			fg = p.bg_raised,
			code = { fg = p.special1, bg = p.bg_deep, s = "bold" },
			strong = { s = "inverted,bold" },
		},
	}
end

local build_builtin = function(p)
	return {
		err = { fg = p.fg3 },
		ls = {
			offset = { fg = p.fg1 },
			user = { fg = p.fg4 },
			group = { fg = p.fg5 },
			atime = { fg = p.warm3 },
			perms = { fg = p.fg1 },
			size = { fg = p.fg2, s = "bold" },
			dir = { fg = p.accent3, s = "bold", before = "ⓓ " },
			file = { fg = p.fg8, before = "ⓕ " },
			target = { fg = p.accent4 },
			link = { fg = p.accent2, before = "ⓛ " },
			socket = { fg = p.special1, before = "ⓢ " },
			block = { fg = p.warning, before = "ⓑ " },
			pipe = { fg = p.error, before = "ⓟ " },
			char = { fg = p.warm1, before = "ⓒ " },
			unknown = { fg = p.special1, before = "ⓤ " },
			exec = { fg = p.success, s = "bold", before = " " },
		},
		alias = {
			name = { fg = p.fg5, s = "bold", align = "right" },
			value = { fg = p.fg4, text_indent = 4 },
		},
		prompt = {
			enabled = { fg = p.success, s = "bold" },
			disabled = { fg = p.fg1 },
		},
		pyvenv = {
			active = { fg = p.accent2, s = "bold" },
			inactive = { fg = p.fg1 },
		},
		cat = {
			line_num = { fg = p.fg4 },
		},
		envlist = {
			var = { fg = p.fg6, s = "bold", align = "left" },
			value = { fg = p.fg4, text_indent = 4 },
		},
		dig = {
			name = { fg = p.warm2, s = "bold" },
			_in = { fg = p.fg3 },
			_type = { fg = p.caution },
			content = { fg = p.accent3 },
			ttl = { fg = p.warm3 },
			ns = { fg = p.fg1, s = "bold" },
			ns_type = { fg = p.fg3 },
			query = { fg = p.fg3, s = "bold,underlined" },
			answer = { fg = p.fg3 },
			domain = { fg = p.fg7, s = "bold" },
			root_ns = { fg = p.fg3, s = "inverted" },
			tld = { fg = p.fg4, s = "inverted" },
			tld_ns = { fg = p.fg5, s = "bold" },
			rtype = { s = "bold" },
			domain_ns = { fg = p.fg6, s = "bold" },
			dnssec_secure = { fg = p.success, s = "bold" },
			dnssec_insecure = { fg = p.warning, s = "bold" },
			dnssec_bogus = { fg = p.error, s = "bold" },
			dnssec_indeterminate = { fg = p.fg4 },
		},
		netstat = {
			src = { fg = p.fg2 },
			dst = { fg = p.fg4 },
			state = { fg = p.fg7 },
			user = { fg = p.fg1 },
		},
		history = {
			date = { fg = p.warm1, after = " " },
			time = { fg = p.warm2, before = "[", after = "] " },
			duration = {},
			status = {},
			cmd = { ok = { fg = p.fg7 }, fail = { fg = p.special1, s = "bold" } },
		},
		wg = {
			net = {
				name = { fg = p.success, s = "bold", after = " " },
				pub_key = { fg = p.warm2, s = "italic" },
			},
			endpoint = {
				text_indent = 4,
				name = { fg = p.warm1, s = "bold", after = " " },
				pub_key = { text_indent = 0, fg = p.warm2, s = "italic" },
				bytes = { fg = p.fg4 },
				seen = { fg = p.warm3 },
				nets = {
					s = "dim,bold",
					fg = p.special2,
				},
			},
		},
		pager = {
			line_num = { fg = p.bg_raised, selected = { s = "bold,inverted" } },
			search_match = { fg = p.bg_deep, bg = p.success, s = "italic,bold" },
			element = {
				focused = { fg = p.warning, s = "bold" },
			},
			status_line = {
				fg = p.accent2,
				filename = { after = " ※ " },
				total_lines = { after = " ※ " },
				size = { after = " ※ " },
				position = { s = "bold,italic" },
				search = {
					input = { bg = p.success, fg = p.bg_deep, s = "bold,inverted" },
					pattern = { before = "/", s = "bold" },
				},
				render_mode = { after = " ※ ", before = " ※ " },
				url = { fg = p.accent3 },
				hint = { fg = p.accent4, s = "italic", before = " ※ " },
				codeblock = { fg = p.bg_raised, lang = { before = " [", fg = p.bg_surface, after = "]" } },
				notification = { fg = p.special1, s = "italic" },
			},
		},
	}
end

local build_prompt = function(p)
	return {
		llm = {
			chat = { fg = p.accent3 },
			backend = { fg = p.accent1, s = "bold" },
			preset = { fg = p.accent1, s = "bold", before = "", after = "" },
			model = { fg = p.success, before = "", after = "" },
			embedding = { fg = p.accent2, before = "Ⓔ " },
			endpoint = { fg = p.accent2, chat = { content = " " }, complete = { content = " " } },
			prompt = { fg = p.accent3, before = "⁜", after = "⁜" },
			temperature = { fg = p.special2, before = "" },
			ctx = { fg = p.success, before = "" },
			tokens = { fg = p.warning, before = "" },
			rate = { fg = p.warm3, before = "" },
			total_cost = { fg = p.warm2, before = " " },
		},
		lua = {
			logo = { fg = p.accent3, s = "bold", content = "" },
		},
		wiki = {
			sep = { fg = p.bg_raised },
			logo = { fg = p.warm1, content = " " },
			db_name = { fg = p.warm3, s = "bold" },
		},
		shell = {
			sep = { fg = p.warm2 },
			git = {
				logo = { fg = p.accent1, s = "dim", content = " " },
				branch = {
					w = 15,
					clean = { fg = p.success },
					dirty = { fg = p.warning },
				},
				modified = { fg = p.caution, before = "←" },
				staged = { fg = p.success, before = "←" },
				untracked = { fg = p.special1, before = "…" },
				ahead = { fg = p.success, before = "↑⬝" },
				behind = { fg = p.warning, before = "↓⬝" },
				remote = { fg = p.accent4 },
				tag = { fg = p.success, w = 20, clip = 5 },
				tag_sep = { fg = p.warm2, content = "@" },
			},
			user = {
				user = { fg = p.success },
				root = { fg = p.error },
				hostname = { fg = p.warning },
			},
			secrets = {
				unlocked = { fg = p.warning, s = "bold", content = " " },
				error = { fg = p.caution, s = "bold", content = "✘" },
			},
			python = {
				logo = { fg = p.warning, content = " ", s = "bold" },
				env = { fg = p.accent2, s = "bold,dim", bg = dark_tint(p.accent4, p.bg_deep) },
			},
			dir = { fg = p.fg8, w = 25, clip = 3 },
		},
	}
end

local build_repl = function(p)
	return {
		lua = {
			separator = { fg = p.accent3, s = "bold", content = "-", fill = true, w = 0.4 },
		},
	}
end

local build_wiki = function(p)
	return {
		separator = { fg = p.accent4, s = "bold", content = "-", fill = true, w = 0.4 },
		item = { fg = p.fg4 },
		key = { fg = p.accent4 },
		title = { s = "bold", fg = p.fg7 },
		score = { fg = p.bg_surface },
	}
end

local build_completion = function(p)
	return {
		fg = p.fg5,
		builtin = { fg = p.accent4 },
		fs_exe = { fg = p.special1 },
		bin = { fg = p.fg5, s = "bold" },
		env = { s = "bold" },
		lua_keyword = { fg = p.accent3, s = "bold" },
		lua_symbol = { fg = p.accent4 },
		history = { text_indent = 4, fg = p.warm3, s = "bold,italic" },
		dir_history = { text_indent = 4, fg = p.fg4, s = "bold,italic" },
		snippet = { text_indent = 4, fg = p.accent1, s = "bold" },
	}
end

local build_input = function(p)
	return {
		input = {
			fg = p.fg8, -- typed text color (matches hard-coded default in term.input)
			s = "normal",
			blank = { w = 1 },
		},
		completion = {
			fg = p.fg5, -- inline ghost-text color (matches hard-coded default in term.input)
		},
	}
end

local build_markdown = function(p)
	local md_default_borders = {
		align = "none",
		indent = 0,
		fg = p.bg_surface,
		clip = -1,
		top_line = { before = "╭", content = "─", after = "╮", fill = true, clip = -1 },
		bottom_line = { before = "╰", content = "─", after = "╯", fill = true, clip = -1 },
		subtitle_line = { before = "├", content = "─", after = "┤", fill = true, clip = -1 },
		v = { content = "│", w = 1, clip = -1 },
	}

	local colored_borders = function(fg)
		local b = {}
		for k, v in pairs(md_default_borders) do
			b[k] = v
		end
		b.fg = fg
		return b
	end

	local md_table_borders = {
		top_left = "┌",
		top = "─",
		top_mid = "┬",
		top_right = "┐",
		left = "│",
		mid = "│",
		right = "│",
		mid_left = "├",
		mid_mid = "┼",
		mid_right = "┤",
		bottom_left = "└",
		bottom = "─",
		bottom_mid = "┴",
		bottom_right = "┘",
		fg = p.bg_surface,
		clip = -1,
	}

	return {
		wrap = 85,
		global_indent = 0,
		fg = p.text,

		heading = {
			s = "bold",
			fg = p.special2,
			h1 = { ts = "triple" },
			h2 = { ts = "double" },
			h3 = { ts = "big", before = "⁜⁜⁜ " },
			h4 = { before = "⁜⁜⁜⁜ " },
			h5 = { before = "⁜⁜⁜⁜⁜ " },
			h6 = { before = "⁜⁜⁜⁜⁜⁜ " },
		},

		code_block = {
			pad = 1,
			border = md_default_borders,
			fg = p.warm3,
			text_fg = p.text,
			lang = {
				s = "italic,bold",
				before = "⧼ ",
				after = " ⧽",
				bg = dark_tint(p.warm3, p.bg_deep),
				fg = p.warm3,
			},
		},

		para = {},

		strong = { s = "bold", fg = p.warm1 },
		emph = { s = "italic", fg = p.warning },
		code = {
			fg = p.fg5,
			s = "bold",
			tbl = { fg = p.special1, before = "{", after = "}" },
			fn = { before = "ʄ(", after = ")", fg = p.special2 },
			num = { fg = p.warm1 },
			str = { fg = p.success },
			bool = { fg = p.accent1 },
			file = { before = "Ⓕ ", fg = p.accent2 },
			dir = { before = "Ⓓ ", fg = p.accent4 },
			opt = { s = "italic" },
			req = { s = "bold" },
			def = { s = "underlined" },
			or_nil = { s = "dim" },
			err = { fg = p.error, s = "dim" },
			arg = { fg = p.warm3 },
			flag = { fg = p.accent3, s = "bold" },
			meta = { fg = p.fg4, s = "italic" },
			neg = { fg = p.error },
			multi = { fg = p.caution },
			status = { fg = p.accent1, s = "italic" },
			date = { ts = "compact", s = "dim" },
		},
		strikethrough = { s = "strikethrough", fg = p.fg3 },

		link = {
			title = { s = "underlined", fg = p.accent3 },
			url = { fg = p.accent3, s = "dim", before = " (", after = ")", clip = 0, w = 0.2 },
		},

		image = {
			alt = { s = "italic", before = "[img: ", after = "]" },
			url = { s = "dim", before = " (", after = ")" },
		},

		thematic_break = {
			w = 0.5,
			align = "center",
			content = "⁓",
			fill = true,
			fg = p.bg_surface,
		},

		list = {
			indent_per_level = 4,
		},

		list_item = {
			ul = {
				content = "⦁ ",
				fg = p.accent4,
			},
			ol = {
				fg = p.fg3,
			},
		},

		task_list = {
			checked = { content = "❴❵ ", fg = p.success },
			unchecked = { content = "❴ ❵ ", fg = p.fg3 },
		},

		table = {
			overflow = "wrap",
			border = md_table_borders,
			header = { s = "bold", fg = p.caution, align = "center" },
			cell = { fg = p.fg8 },
		},

		footnote_ref = { ts = "superscript", s = "bold", fg = p.accent3 },
		footnotes = {
			separator = { fg = p.bg_surface },
		},
		footnote = {
			marker = { s = "bold", fg = p.accent3 },
			content = { fg = p.fg3 },
		},

		div = {
			default = {
				align = "center",
				w = 0.8,
				pad = 1,
				border = md_default_borders,
				fg = p.fg8,
				label = { s = "italic,bold", before = "⧼ ", after = " ⧽", fg = p.accent4, w = 0 },
			},
			warning = {
				fg = p.caution,
				border = colored_borders(p.caution),
				label = {
					s = "italic,bold",
					before = "⧼ ",
					after = " ⧽",
					bg = dark_tint(p.caution, p.bg_mid),
					fg = p.caution,
				},
			},
			note = {
				fg = p.accent3,
				border = colored_borders(p.accent3),
				label = {
					s = "italic,bold",
					before = "⧼ ",
					after = " ⧽",
					bg = dark_tint(p.accent3, p.bg_mid),
					fg = p.accent3,
				},
			},
			tip = {
				fg = p.success,
				border = colored_borders(p.success),
				label = {
					s = "italic,bold",
					before = "⧼ ",
					after = " ⧽",
					bg = dark_tint(p.success, p.bg_mid),
					fg = p.success,
				},
			},
			caution = {
				fg = p.error,
				border = colored_borders(p.error),
				label = {
					s = "italic,bold",
					before = "⧼ ",
					after = " ⧽",
					bg = dark_tint(p.error, p.bg_mid),
					fg = p.error,
				},
			},
		},

		blockquote = {
			fg = p.fg3,
			indent = 0,
			bar = { content = "┃ ", fg = p.accent3 },
		},
	}
end

local build_widget = function(p)
	return {
		fg = p.fg8,
		title = { s = "bold", align = "center" },
		border = {
			fg = p.bg_surface,
			align = "none",
			clip = -1,
			top_line = { before = "┌", content = "─", after = "┐", fill = true, clip = -1 },
			bottom_line = { before = "└", content = "─", after = "┘", fill = true, clip = -1 },
			separator = { before = "├", content = "─", after = "┤", fill = true, clip = -1 },
			v = { content = "│", w = 1, clip = -1 },
			label = { w = 0.8, clip = 7 },
		},
		chooser = {
			item = { align = "center", bg = p.bg_mid },
			selected = { s = "inverted", align = "center" },
			marked = { content = "◉ ", s = "bold", w = 2 },
			unmarked = { content = "  ", w = 2 },
		},
		file = {
			item = { text_indent = 1, align = "left" },
			selected = { text_indent = 1, align = "left", s = "inverted" },
			directory = { text_indent = 1, align = "left", s = "bold" },
			search_text = { text_indent = 1, align = "left" },
			search_placeholder = { text_indent = 1, align = "left", s = "italic", fg = p.fg3 },
			pinned = { text_indent = 1, align = "left", s = "bold", fg = p.accent1 },
			rel_path = { fg = p.fg2, s = "italic" },
			no_results = { align = "center", s = "italic", fg = p.fg3 },
		},
		confirm = {
			yes = { s = "bold" },
			no = {},
			selected = { s = "inverted" },
		},
		form = {
			label = { text_indent = 1, align = "left", after = ": ", s = "bold" },
			focused = { text_indent = 1, align = "left", after = ": ", s = "bold,inverted" },
			input = { s = "italic", line = { content = "_", fill = true }, blank = { w = 1 } },
		},
		scrollbar = {
			track = { fg = p.bg_surface, content = "│" },
			thumb = { fg = p.fg3, content = "┃" },
		},
	}
end

local build_lem = function(p)
	return {
		gutter = {
			fg = p.fg3,
			line_number = { fg = p.bg_surface },
			current_line = { fg = p.fg4, s = "bold" },
			diagnostic_error = { fg = p.error, s = "bold" },
			wrap_indicator = { fg = p.fg2 },
		},
		status = {
			bg = p.bg_deep,
			fg = p.fg5,
			filename = { fg = p.fg7 },
			modified = { fg = p.warning, s = "bold" },
			position = { fg = p.fg6 },
			mode = { fg = p.accent1, s = "bold" },
			mode_insert = { fg = p.success, s = "bold" },
			mode_visual = { fg = p.special2, s = "bold" },
			filetype = { fg = p.fg4 },
			buffer_index = { fg = p.fg4 },
		},
		command = {
			input = { fg = p.fg7 },
			prompt = { fg = p.accent1, s = "bold" },
		},
		message = {
			info = { fg = p.fg5 },
			warning = { fg = p.warning },
			error = { fg = p.error },
		},
		text = {
			fg = p.text,
			selection = { bg = p.bg_raised },
			search_match = { bg = p.warning, fg = p.bg_deep },
			bracket_match = { bg = p.fg4, fg = p.bg_deep, s = "bold" },
			diagnostic = { fg = p.error, s = "underlined" },
			current_line = { bg = p.bg_mid },
		},
		syntax = {
			literal = { fg = p.success },
			definition = { fg = p.warning, s = "bold" },
			comment = { fg = p.accent3, s = "italic" },
			disabled = { fg = p.warm2 },
			error = { fg = p.error },
			punctuation = { fg = p.fg3 },
			operator = { fg = p.fg4 },
			directive = { fg = p.fg2, s = "italic" },
		},
		completion = {
			fg = p.fg3,
			s = "italic",
		},
	}
end

-- Registered LILPACK section builders: name -> function(palette) -> rss_table
local registered_sections = {}

-- Registered LILPACK themes: name -> { palette = {...}, ... }
local registered_themes = {}

local build_defaults = function(p)
	local d = {
		shell = {
			errors = build_errors(p),
			builtin = build_builtin(p),
			prompt = build_prompt(p),
			completion = build_completion(p),
			input = build_input(p),
			repl = build_repl(p),
			wiki = build_wiki(p),
			widget = build_widget(p),
			lem = build_lem(p),
		},
		markdown = build_markdown(p),
	}
	for name, builder_fn in pairs(registered_sections) do
		d[name] = builder_fn(p)
	end
	return d
end

local active_palette = std.tbl.copy(default_palette)
local defaults = build_defaults(active_palette)

local active_theme_name = "default"
local active_theme_data = {}

local set = function(name)
	if name == "default" then
		active_palette = std.tbl.copy(default_palette)
		defaults = build_defaults(active_palette)
		active_theme_name = "default"
		active_theme_data = {}
		for section, _ in pairs(defaults) do
			active_theme_data[section] = std.tbl.copy(default_overrides[section] or {})
		end
		generation = generation + 1
		rss_cache = {}
		return true
	end
	-- Check registered LILPACK themes first, then bundled catalog
	local data = registered_themes[name]
	if not data then
		local ok, catalog = pcall(require, "theme.catalog")
		if ok and catalog[name] then
			data = catalog[name]
		end
	end
	if not data then
		return nil, "theme not found: " .. name
	end
	-- Merge palette: default -> theme
	active_palette = std.tbl.copy(default_palette)
	if data.palette then
		active_palette = std.tbl.merge(active_palette, std.tbl.copy(data.palette))
	end
	defaults = build_defaults(active_palette)
	-- Element-level overrides from theme
	active_theme_name = name
	active_theme_data = {}
	for section, _ in pairs(defaults) do
		active_theme_data[section] = data[section] or {}
	end
	generation = generation + 1
	rss_cache = {}
	return true
end

-- Initialize with the built-in default (applies default_overrides), sharing the
-- same code path as a runtime `set("default")`.
set("default")

local current = function()
	return active_theme_name
end

local list = function()
	local result = {}
	local seen = {}
	-- Bundled themes
	local ok, catalog = pcall(require, "theme.catalog")
	if ok then
		for name, _ in pairs(catalog) do
			if not seen[name] then
				table.insert(result, { name = name, source = "bundled" })
				seen[name] = true
			end
		end
	end
	-- Registered LILPACK themes
	for name, _ in pairs(registered_themes) do
		if not seen[name] then
			table.insert(result, { name = name, source = "lilpack" })
			seen[name] = true
		end
	end
	table.sort(result, function(a, b)
		return a.name < b.name
	end)
	return result
end

local get = function(section, extra_overrides)
	local key = section or ""
	if not rss_cache[key] then
		local merged = std.tbl.copy(defaults[key] or {})
		merged = std.tbl.merge(merged, std.tbl.copy(active_theme_data[key] or {}))
		rss_cache[key] = merged
	end
	local result = std.tbl.copy(rss_cache[key])
	if type(extra_overrides) == "table" then
		result = std.tbl.merge(result, extra_overrides)
	end
	return result
end

local subscribe = function(section, sub_key)
	local gen
	local cached_tss
	return function()
		if generation ~= gen then
			local rss = get(section)
			if sub_key then
				rss = rss[sub_key] or {}
			end
			cached_tss = style.new(rss)
			gen = generation
		end
		return cached_tss
	end
end

local get_palette = function()
	return std.tbl.copy(active_palette)
end

local register_section = function(name, builder_fn)
	registered_sections[name] = builder_fn
	defaults[name] = builder_fn(active_palette)
	generation = generation + 1
	rss_cache = {}
end

local register_theme = function(name, data)
	registered_themes[name] = data
end

return {
	get = get,
	set = set,
	current = current,
	list = list,
	subscribe = subscribe,
	palette = get_palette,
	register_section = register_section,
	register_theme = register_theme,
}