local config = require("gitea.config")
local auth = require("gitea.auth")
local curl = require("plenary.curl")

local M = {}

local function get_base_url()
  local server = config.values.server_url
  if not server or server == "" then
    -- fallback
    server = "https://gitea.example.com"
  end
  return server
end

local function get_auth_header()
  local token = auth.get_token()
  if not token or token == "" then
    error("[gitea.nvim] Missing Gitea token. Please run :Gitea again or restart after entering a token.")
  end
  return "token " .. token
end

local function request(method, endpoint, opts)
  opts = opts or {}
  local url = get_base_url() .. endpoint
  local headers = opts.headers or {}
  headers["Authorization"] = get_auth_header()
  headers["Content-Type"] = "application/json"
  local result = curl.request({
    url = url,
    method = method,
    headers = headers,
    timeout = 5000, -- we can also read config.values.timeout
    body = opts.body and vim.json.encode(opts.body) or nil,
  })
  return result
end

-------------------------------------------------------
-- ISSUES
-------------------------------------------------------
function M.list_issues(owner, repo, opts)
  local endpoint = string.format("/api/v1/repos/%s/%s/issues", owner, repo)
  local result = request("GET", endpoint, { query = opts })
  if result and result.status == 200 then
    return vim.json.decode(result.body)
  end
  return nil, result and result.status
end

function M.get_issue(owner, repo, number)
  local endpoint = string.format("/api/v1/repos/%s/%s/issues/%d", owner, repo, number)
  local result = request("GET", endpoint)
  if result and result.status == 200 then
    return vim.json.decode(result.body)
  end
  return nil, result and result.status
end

function M.create_issue(owner, repo, data)
  -- data = { title = "", body = "", labels = {"bug"}, etc. }
  local endpoint = string.format("/api/v1/repos/%s/%s/issues", owner, repo)
  local result = request("POST", endpoint, { body = data })
  if result and result.status == 201 then
    return vim.json.decode(result.body)
  end
  return nil, result and result.status
end

function M.edit_issue(owner, repo, number, data)
  local endpoint = string.format("/api/v1/repos/%s/%s/issues/%d", owner, repo, number)
  local result = request("PATCH", endpoint, { body = data })
  if result and result.status == 200 then
    return vim.json.decode(result.body)
  end
  return nil, result and result.status
end

function M.close_issue(owner, repo, number)
  -- Gitea: state -> "closed"
  return M.edit_issue(owner, repo, number, { state = "closed" })
end

function M.reopen_issue(owner, repo, number)
  return M.edit_issue(owner, repo, number, { state = "open" })
end

function M.comment_issue(owner, repo, number, body)
  local endpoint = string.format("/api/v1/repos/%s/%s/issues/%d/comments", owner, repo, number)
  local result = request("POST", endpoint, { body = { body = body } })
  if result and result.status == 201 then
    return vim.json.decode(result.body)
  end
  return nil, result and result.status
end

-------------------------------------------------------
-- PULL REQUESTS
-------------------------------------------------------
function M.list_pull_requests(owner, repo, opts)
  local endpoint = string.format("/api/v1/repos/%s/%s/pulls", owner, repo)
  local result = request("GET", endpoint, { query = opts })
  if result and result.status == 200 then
    return vim.json.decode(result.body)
  end
  return nil, result and result.status
end

function M.get_pull_request(owner, repo, number)
  local endpoint = string.format("/api/v1/repos/%s/%s/pulls/%d", owner, repo, number)
  local result = request("GET", endpoint)
  if result and result.status == 200 then
    return vim.json.decode(result.body)
  end
  return nil, result and result.status
end

function M.create_pull_request(owner, repo, data)
  -- data = { head = "branch", base = "master", title = "My PR", body = "..." }
  local endpoint = string.format("/api/v1/repos/%s/%s/pulls", owner, repo)
  local result = request("POST", endpoint, { body = data })
  if result and result.status == 201 then
    return vim.json.decode(result.body)
  end
  return nil, result and result.status
end

function M.edit_pull_request(owner, repo, number, data)
  local endpoint = string.format("/api/v1/repos/%s/%s/pulls/%d", owner, repo, number)
  local result = request("PATCH", endpoint, { body = data })
  if result and result.status == 200 then
    return vim.json.decode(result.body)
  end
  return nil, result and result.status
end

function M.merge_pull_request(owner, repo, number, merge_style, merge_title, merge_message)
  -- merge_style: "merge"|"rebase"|"squash" (in Gitea it's "merge"|"rebase"|"rebase-merge"|"squash" - 
  --   see Gitea docs for specifics; we can map the user’s choice to Gitea’s).
  local endpoint = string.format("/api/v1/repos/%s/%s/pulls/%d/merge", owner, repo, number)
  local result = request("POST", endpoint, {
    body = {
      Do = merge_style or "merge",    -- e.g. "merge"
      MergeTitleField = merge_title or "",
      MergeMessageField = merge_message or "",
    }
  })
  if result and result.status == 200 then
    return vim.json.decode(result.body)
  end
  return nil, result and result.status
end

function M.close_pull_request(owner, repo, number)
  return M.edit_pull_request(owner, repo, number, { state = "closed" })
end

function M.reopen_pull_request(owner, repo, number)
  return M.edit_pull_request(owner, repo, number, { state = "open" })
end

function M.comment_pull_request(owner, repo, number, body)
  -- same endpoint as issues for Gitea. A PR is an issue with is_pull = true
  return M.comment_issue(owner, repo, number, body)
end

return M