local ok, ts_utils = pcall(require, "nvim-treesitter.ts_utils")
assert(ok, "neogen requires nvim-treesitter to operate :(")

---@diagnostic disable-next-line: lowercase-global
neogen = {}

-- Require utilities
neogen.utilities = {}
require("neogen.utilities.extractors")
require("neogen.utilities.nodes")
require("neogen.utilities.cursor")

-- Require defaults
require("neogen.locators.default")
require("neogen.granulators.default")
require("neogen.generators.default")

neogen.generate = function(opts)
    opts = opts or {
        type = "func",
    }

    local parser = vim.treesitter.get_parser(0, vim.bo.filetype)
    local tstree = parser:parse()[1]
    local tree = tstree:root()

    local language = neogen.configuration.languages[vim.bo.filetype]

    if language then
        language.locator = language.locator or neogen.default_locator
        language.granulator = language.granulator or neogen.default_granulator
        language.generator = language.generator or neogen.default_generator

        if not language.parent[opts.type] or not language.data[opts.type] then
            return
        end

        -- Use the language locator to locate one of the required parent nodes above the cursor
        local located_parent_node = language.locator({
            root = tree,
            current = ts_utils.get_node_at_cursor(0),
        }, language.parent[opts.type])

        if not located_parent_node then
            return
        end

        -- Use the language granulator to get the required content inside the node found with the locator
        local data = language.granulator(located_parent_node, language.data[opts.type])

        if data then
            -- Will try to generate the documentation from a template and the data found from the granulator
            local to_place, start_column, content = language.generator(
                located_parent_node,
                data,
                language.template,
                opts.type
            )

            if #content ~= 0 then
                neogen.utilities.cursor.del_extmarks() -- Delete previous extmarks before setting any new ones

                local jump_text = language.jump_text or neogen.configuration.jump_text

                --- Removes jump_text marks and keep the second part of jump_text|other_text if there is one (which is other_text)
                local delete_marks = function(v)
                    local pattern = jump_text .. "[|%w]+"
                    local matched = string.match(v, pattern)

                    if matched then
                        local split = vim.split(matched, "|", true)
                        if #split == 2 and neogen.configuration.input_after_comment == false then
                            return string.gsub(v, jump_text .. "|", "")
                        end
                    else
                        return string.gsub(v, jump_text, "")
                    end

                    return string.gsub(v, pattern, "")
                end

                local content_with_marks = vim.deepcopy(content)

                -- delete all jump_text marks
                content = vim.tbl_map(delete_marks, content)

                -- Append the annotation in required place
                vim.fn.append(to_place, content)

                -- Place cursor after annotations and start editing
                -- First and last extmarks are needed to know the range of inserted content
                if neogen.configuration.input_after_comment == true then
                    -- Creates extmark for the beggining of the content
                    neogen.utilities.cursor.create(to_place + 1, start_column, true)
                    -- Creates extmarks for the content
                    for i, value in pairs(content_with_marks) do
                        local start = 0
                        local count = 0
                        while true do
                            start = string.find(value, jump_text, start + 1)
                            if not start then
                                break
                            end
                            neogen.utilities.cursor.create(to_place + i, start - count * #jump_text)
                            count = count + 1
                        end
                    end

                    -- Creates extmark for the end of the content
                    neogen.utilities.cursor.create(to_place + #content + 1, 0, true)

                    neogen.utilities.cursor.jump({ first_time = true })
                end
            end
        end
    end
end

function neogen.jump_next()
    neogen.utilities.cursor.jump()
end

function neogen.jump_prev()
    neogen.utilities.cursor.jump_prev()
end

function neogen.jumpable(reverse)
    return neogen.utilities.cursor.jumpable(reverse)
end

function neogen.generate_command()
    vim.api.nvim_command('command! -range -bar Neogen lua require("neogen").generate()')
end

neogen.setup = function(opts)
    neogen.configuration = vim.tbl_deep_extend("keep", opts or {}, {
        input_after_comment = true, -- bool, If you want to jump with the cursor after annotation
        jump_text = "$1", -- symbol to find for jumping cursor in template
        -- DEFAULT CONFIGURATION
        languages = {
            lua = require("neogen.configurations.lua"),
            python = require("neogen.configurations.python"),
            javascript = require("neogen.configurations.javascript"),
            typescript = require("neogen.configurations.typescript"),
            c = require("neogen.configurations.c"),
            cpp = require("neogen.configurations.c"),
            go = require("neogen.configurations.go"),
            java = require("neogen.configurations.java"),
            rust = require("neogen.configurations.rust"),
        },
    })

    if neogen.configuration.enabled == true then
        neogen.generate_command()
    end
end

return neogen