package server

import (
	"net/http"
	"os"
	"path/filepath"
	"strings"

	"github.com/gin-gonic/gin"

	"github.com/dal/kaos/internal/supervisor"
)

// searchResult represents a single search result.
type searchResult struct {
	Type    string // "task", "doc", "report"
	Icon    string // emoji icon
	Title   string // display title
	Link    string // URL to navigate to
	Snippet string // context around the match
	Status  string // task status (only for tasks)
}

// searchResultsData holds data for the search results template.
type searchResultsData struct {
	Query   string
	Results []searchResult
}

// handleSearch serves search results as an HTML fragment.
func (s *Server) handleSearch(c *gin.Context) {
	query := strings.TrimSpace(c.Query("q"))

	if query == "" {
		c.String(http.StatusOK, "")
		return
	}

	root := s.projectRoot()
	var results []searchResult

	// 1. Search tasks
	tasks, _ := supervisor.ScanTasks(s.Config.TasksDir)
	for _, t := range tasks {
		if matchTask(t, query) {
			snippet := taskSnippet(t, query)
			results = append(results, searchResult{
				Type:    "task",
				Icon:    "📋",
				Title:   t.ID + ": " + t.Title,
				Link:    "/task/" + t.ID,
				Snippet: snippet,
				Status:  t.Status,
			})
		}
	}

	// 2. Search documents (non-report .md files)
	docs := scanMarkdownFiles(root)
	for _, doc := range docs {
		// Skip task files and reports (handled separately)
		if strings.HasPrefix(doc.Path, "TASKS/") {
			continue
		}
		content, err := os.ReadFile(filepath.Join(root, doc.Path))
		if err != nil {
			continue
		}
		if containsInsensitive(string(content), query) || containsInsensitive(doc.Path, query) {
			snippet := extractSnippet(string(content), query)
			results = append(results, searchResult{
				Type:    "doc",
				Icon:    "📄",
				Title:   doc.Path,
				Link:    "/docs/" + doc.Path,
				Snippet: snippet,
			})
		}
	}

	// 3. Search reports
	reportsDir := filepath.Join(s.Config.TasksDir, "reports")
	entries, _ := os.ReadDir(reportsDir)
	for _, entry := range entries {
		if entry.IsDir() || !strings.HasSuffix(entry.Name(), ".md") {
			continue
		}
		content, err := os.ReadFile(filepath.Join(reportsDir, entry.Name()))
		if err != nil {
			continue
		}
		if containsInsensitive(string(content), query) || containsInsensitive(entry.Name(), query) {
			// Extract task ID from report filename (T01-report.md → T01)
			taskID := strings.TrimSuffix(entry.Name(), "-report.md")
			snippet := extractSnippet(string(content), query)
			results = append(results, searchResult{
				Type:    "report",
				Icon:    "📊",
				Title:   entry.Name(),
				Link:    "/report/" + taskID,
				Snippet: snippet,
			})
		}
	}

	// Limit results
	if len(results) > 20 {
		results = results[:20]
	}

	data := searchResultsData{
		Query:   query,
		Results: results,
	}

	c.Header("Content-Type", "text/html; charset=utf-8")
	c.String(http.StatusOK, renderSearchResults(data))
}

// matchTask checks if a task matches the query (case insensitive).
func matchTask(t supervisor.Task, query string) bool {
	q := strings.ToLower(query)
	return containsInsensitive(t.ID, query) ||
		containsInsensitive(t.Title, query) ||
		containsInsensitive(t.Description, query) ||
		containsInsensitive(t.Agent, query) ||
		strings.ToLower(t.Status) == q
}

// taskSnippet returns a snippet from the task for display.
func taskSnippet(t supervisor.Task, query string) string {
	// Try to find match in description first
	if t.Description != "" && containsInsensitive(t.Description, query) {
		return extractSnippet(t.Description, query)
	}
	// Fall back to description start
	if t.Description != "" {
		desc := t.Description
		if len(desc) > 100 {
			desc = desc[:100] + "..."
		}
		return desc
	}
	return t.Agent + " · " + t.Model
}

// containsInsensitive checks if s contains substr (case insensitive).
func containsInsensitive(s, substr string) bool {
	return strings.Contains(strings.ToLower(s), strings.ToLower(substr))
}

// extractSnippet extracts a snippet around the first match with context.
func extractSnippet(content, query string) string {
	lower := strings.ToLower(content)
	q := strings.ToLower(query)

	idx := strings.Index(lower, q)
	if idx == -1 {
		// Return first 100 chars
		if len(content) > 100 {
			return content[:100] + "..."
		}
		return content
	}

	// Get context: 40 chars before and 60 chars after
	start := idx - 40
	if start < 0 {
		start = 0
	}
	end := idx + len(query) + 60
	if end > len(content) {
		end = len(content)
	}

	snippet := content[start:end]

	// Clean up: remove newlines, trim
	snippet = strings.ReplaceAll(snippet, "\n", " ")
	snippet = strings.ReplaceAll(snippet, "\r", "")
	snippet = strings.TrimSpace(snippet)

	if start > 0 {
		snippet = "..." + snippet
	}
	if end < len(content) {
		snippet = snippet + "..."
	}

	return snippet
}