package agents

import (
	"context"
	"fmt"
	"io"
	"log/slog"
	"net/url"
	"slices"
	"strings"
	"sync"
	"time"

	"gitea.stevedudenhoeffer.com/steve/go-extractor"
	"gitea.stevedudenhoeffer.com/steve/go-extractor/sites/duckduckgo"
	gollm "gitea.stevedudenhoeffer.com/steve/go-llm"
)

func deferClose(c io.Closer) {
	if c != nil {
		_ = c.Close()
	}

}

type SearchTool struct {
	Name        string
	Description string
	Function    func(ctx context.Context, src *url.URL, questions []string) (Knowledge, error)
}

// SearchAndUseTools will search duckduckgo for the given question, and then ask the LLM to select a search result to
// analyze. The LLM will be given a list of tools to use to analyze the search result, and then the LLM will be asked to
// determine if the search results answers the question.
// If the context contains a "browser" key that is an extractor.Browser, it will use that browser to search, otherwise a
// new one will be created and used for the life of this search and then closed.
// searchQuery is the question to search for.
// questions is the list of questions that the LLM is trying to answer with the search results.
// loops is the number of times to ask the LLM to analyze results if there are remaining questions before giving up.
// readers is a list of functions that will be used to read the search results. Any knowledge gained from these readers
// will be combined and returned.
// messages will be appended to all search results.  The types of messages that can be appended are both string and
// gollm.Message.
func (a Agent) SearchAndUseTools(ctx context.Context, searchQuery string, questions []string, loops int, allowConcurrent bool, maxReads int, tools []SearchTool, messages ...any) (Knowledge, error) {
	var knowledge = Knowledge{
		OriginalQuestions:  questions,
		RemainingQuestions: questions,
	}

	browser, ok := ctx.Value("browser").(extractor.Browser)
	if !ok {
		b, err := extractor.NewPlayWrightBrowser(extractor.PlayWrightBrowserOptions{})
		if err != nil {
			return knowledge, err
		}

		ctx = context.WithValue(ctx, "browser", b)
		browser = b
		defer deferClose(browser)
	}

	cfg := duckduckgo.Config{
		SafeSearch: duckduckgo.SafeSearchOff,
		Region:     "us-en",
	}

	page, err := cfg.OpenSearch(ctx, browser, searchQuery)
	defer deferClose(page)
	if err != nil {
		return knowledge, err
	}

	var searchResults []duckduckgo.Result

	// filterResults will remove any search results that are in oldSearchResults, or are empty
	filterResults := func(in []duckduckgo.Result) []duckduckgo.Result {
		var res []duckduckgo.Result
		for _, r := range in {
			if r.URL == "" {
				continue
			}

			res = append(res, r)
		}

		return res
	}

	if maxReads == 0 {
		maxReads = 100
	}

	var lock sync.Mutex
	var analyzed []int
	var converted []gollm.Function

	for _, t := range tools {
		fn := gollm.NewFunction(t.Name, t.Description,
			func(c *gollm.Context, arg struct {
				Num int `description:"The # of search result to analyze."`
			}) (any, error) {
				i := arg.Num - 1

				defer func() {
					lock.Lock()
					defer lock.Unlock()
					analyzed = append(analyzed, i)
				}()

				if i < 0 || i >= len(searchResults) {
					return nil, fmt.Errorf("index out of range: expect 1-%d", len(searchResults))
				}

				u, err := url.Parse(searchResults[i].URL)
				if err != nil {
					return nil, fmt.Errorf("error parsing url: %w", err)
				}

				return t.Function(c.Context, u, questions)
			})
		converted = append(converted, fn)
	}

	for i := 0; i < loops; i++ {
		// if any search results have already been analyzed, remove them
		// but to make this easier, sort the list of analyzed results descending so they can be removed in order
		// without changing the indexes of the remaining results

		// but first remove any duplicates
		var unique = map[int]struct{}{}
		for _, v := range analyzed {
			unique[v] = struct{}{}
		}

		analyzed = analyzed[:0]
		for k := range unique {
			analyzed = append(analyzed, k)
		}

		slices.Sort(analyzed)
		for j := len(analyzed) - 1; j >= 0; j-- {
			v := analyzed[j]
			if v < 0 || v >= len(searchResults) {
				continue
			}

			searchResults = append(searchResults[:analyzed[j]], searchResults[analyzed[j]+1:]...)
		}

		// remove any search results that have already been analyzed
		analyzed = analyzed[:0]

		_ = page.LoadMore()
		time.Sleep(2 * time.Second)

		searchResults = filterResults(page.GetResults())

		a = a.WithSystemPrompt(`You are searching DuckDuckGo for the answer to the question that will be posed by the user.  The search results will be provided in system messages in the format of: #. "https://url.here" - "Title of Page" - "Description here". For instance:
1. "https://example.com" - "Example Title" - "This is an example description."
2. "https://example2.com" - "Example Title 2" - "This is an example description 2."

Use appropriate tools to analyze the search results and determine if they answer the question.`).
			WithSystemPromptSuffix(``).
			WithToolbox(gollm.NewToolBox(converted...).WithRequireTool(true))

		var searches = make([]string, len(searchResults))
		for i, r := range searchResults {
			searches[i] = fmt.Sprintf("%d. %q - %q - %q", i+1, r.URL, r.Title, r.Description)
		}

		if len(searches) > 0 {
			messages = append(messages, "The search results are:\n"+strings.Join(searches, "\n"))
		}

		var results CallAndExecuteResults
		if allowConcurrent {
			results, err = a.CallAndExecuteParallel(ctx, messages...)
		} else {
			results, err = a.CallAndExecute(ctx, messages...)
		}

		if err != nil {
			return knowledge, fmt.Errorf("error executing search function: %w", err)
		}
		slog.Info("search results called and executed", "error", err, "results text", results.Text, "results", results.CallResults)

		var learned []Knowledge
		for _, r := range results.CallResults {
			if r.Error != nil {
				continue
			}

			if k, ok := r.Result.(Knowledge); ok {
				learned = append(learned, k)
			} else {
				slog.Error("result is not knowledge", "result", r.Result)
			}
		}

		knowledge, err = a.KnowledgeIntegrate(ctx, knowledge, learned...)
		if err != nil {
			return knowledge, fmt.Errorf("error integrating knowledge: %w", err)
		}

		if len(knowledge.RemainingQuestions) == 0 {
			return knowledge, nil
		}
	}

	return knowledge, nil
}

func (a Agent) SearchAndRead(ctx context.Context, searchQuery string, questions []string, allowConcurrent bool, maxReads int) (Knowledge, error) {
	return a.SearchAndUseTools(ctx, searchQuery, questions, 2, allowConcurrent, maxReads, []SearchTool{
		{
			Name:        "readpage",
			Description: "Read the search result and see if it answers the question.  Try to avoid using this on low quality or spammy sites. You can use this function" + fmt.Sprint(maxReads) + " times, but do not call it multiple times on the same result.",
			Function:    a.ReadPage,
		},
		{
			Name:        "youtube",
			Description: "Read the transcript to a youtube video and see if it answers the question.  Try to avoid using this on low quality or spammy links.  You can use this function" + fmt.Sprint(maxReads) + " times, but do not call it multiple times on the same result.",
			Function:    a.ReadYouTubeTranscript,
		},
	},
		gollm.Message{Role: gollm.RoleSystem, Text: "For youtube links, only use the youtube tool.  For other links, only use the readpage tool."})
}