---- Documentation for jsonfly ----
--- Type definitions
---@class Options
---@field key_max_length number - Length for the key column, 0 for no column-like display, Default: 50
---@field key_exact_length boolean - Whether to use exact length for the key column, This will pad the key column with spaces to match the length, Default: false
---@field max_length number - Maximum length for the value column, Default: 9999 (basically no limit)
---@field overflow_marker string - Marker for truncated values, Default: "…"
---@field conceal boolean|"auto" - Whether to conceal strings, If `true` strings will be concealed, If `false` strings will be displayed as they are, If `"auto"` strings will be concealed if `conceallevel` is greater than 0, Default: "auto"
---@field prompt_title string - Title for the prompt, Default: "JSON(fly)"
---@field highlights Highlights - Highlight groups for different types
---@field jump_behavior "key_start"|"value_start" - Behavior for jumping to the location, "key_start" == Jump to the start of the key, "value_start" == Jump to the start of the value, Default: "key_start"
---@field subkeys_display "normal"|"waterfall" - Display subkeys in a normal or waterfall style, Default: "normal"
---@field backend "lua"|"lsp" - Backend to use for parsing JSON, "lua" = Use our own Lua parser to parse the JSON, "lsp" = Use your LSP to parse the JSON (currently only https://github.com/Microsoft/vscode-json-languageservice is supported). If the "lsp" backend is selected but the LSP fails, it will fallback to the "lua" backend, Default: "lsp"
---
---@class Highlights
---@field number string - Highlight group for numbers, Default: "@number.json"
---@field boolean string - Highlight group for booleans, Default: "@boolean.json"
---@field string string - Highlight group for strings, Default: "@string.json"
---@field null string - Highlight group for null values, Default: "@constant.builtin.json"
---@field other string - Highlight group for other types, Default: "@label.json"

local parsers = require"jsonfly.parsers"
local utils = require"jsonfly.utils"
local cache = require"jsonfly.cache"

local json = require"jsonfly.json"
local finders = require "telescope.finders"
local pickers = require "telescope.pickers"
local conf = require"telescope.config".values
local make_entry = require "telescope.make_entry"
local entry_display = require "telescope.pickers.entry_display"

---@type Options
local opts = {
    key_max_length = 50,
    key_exact_length = false,
    max_length = 9999,
    overflow_marker = "…",
    conceal = "auto",
    prompt_title = "JSON(fly)",
    highlights = {
        string = "@string.json",
        number = "@number.json",
        boolean = "@boolean.json",
        null = "@constant.builtin.json",
        other = "@label.json",
    },
    jump_behavior = "key_start",
    subkeys_display = "normal",
    backend = "lsp",
}

---@param entries Entry[]
---@param buffer number
local function show_picker(entries, buffer)
    local filename = vim.api.nvim_buf_get_name(buffer)

    local displayer = entry_display.create {
        separator = " ",
        items = {
            { width = 1 },
            opts.key_exact_length and { width = opts.key_max_length } or { remaining = true },
            { remaining = true },
        },
    }
    ---@type boolean
    local conceal

    if opts.conceal == "auto" then
        conceal = vim.o.conceallevel > 0
    else
        conceal = opts.conceal == true
    end

    pickers.new(opts, {
        prompt_title = opts.prompt_title,
        finder = finders.new_table {
            results = entries,
            ---@param entry Entry
            entry_maker = function(entry)
                local _, raw_depth = entry.key:gsub("%.", ".")
                local depth = (raw_depth or 0) + 1

                return make_entry.set_default_entry_mt({
                    value = buffer,
                    ordinal = entry.key,
                    display = function(_)
                        local preview, hl_group_key = utils:create_display_preview(entry.value, conceal)

                        local key = opts.subkeys_display == "normal" and entry.key or utils:replace_previous_keys(entry.key, " ")

                        return displayer {
                            { depth, "TelescopeResultsNumber"},
                            {
                                utils:truncate_overflow(
                                    key,
                                    opts.key_max_length,
                                    opts.overflow_marker
                                ),
                                "@property.json",
                            },
                            {
                                utils:truncate_overflow(
                                    preview,
                                    opts.max_length,
                                    opts.overflow_marker
                                ),
                                opts.highlights[hl_group_key] or "TelescopeResultsString",
                            },
                        }
                    end,

                    bufnr = buffer,
                    filename = filename,
                    lnum = entry.position.line_number,
                    col = opts.jump_behavior == "key_start"
                            and entry.position.key_start
                            -- Use length ("#" operator) as vim jumps to the bytes, not characters
                            or entry.position.value_start
                }, opts)
            end,
        },
        previewer = conf.grep_previewer(opts),
        sorter = conf.generic_sorter(opts),
        sorting_strategy = "ascending",
    }):find()
end

return require"telescope".register_extension {
    setup = function(extension_config)
        opts = vim.tbl_deep_extend("force", opts, extension_config or {})
    end,
    exports = {
        jsonfly = function(xopts)
            local current_buf = vim.api.nvim_get_current_buf()

            local cached_entries = cache:get_cache(current_buf)

            if cached_entries ~= nil then
                show_picker(cached_entries, current_buf)
                return
            end

            cache:register_listeners(current_buf)

            local content_lines = vim.api.nvim_buf_get_lines(current_buf, 0, -1, false)
            local content = table.concat(content_lines, "\n")

            local function run_lua_parser()
                local parsed = json:decode(content)
                local entries = parsers:get_entries_from_lua_json(parsed)

                cache:cache_buffer(current_buf, entries)

                show_picker(entries, current_buf)
            end

            if opts.backend == "lsp" then
                local params = vim.lsp.util.make_position_params(xopts.winnr)

                vim.lsp.buf_request(
                    current_buf,
                    "textDocument/documentSymbol",
                    params,
                    function(error, lsp_response)
                        if error then
                            run_lua_parser()
                            return
                        end

                        local entries = parsers:get_entries_from_lsp_symbols(lsp_response)
                        cache:cache_buffer(current_buf, entries)

                        show_picker(entries, current_buf)
                    end
                )
            else
                run_lua_parser()
            end
        end
    }
}