package handlers

import (
	"encoding/json"
	"fmt"
	"net/http"
	"strconv"
	"strings"

	"prompt-generator/internal/db"
	"prompt-generator/internal/models"
)

func GetBuilderSessions(w http.ResponseWriter, r *http.Request) {
	rows, err := db.DB.Query("SELECT id, title, project_name, final_prompt, claude_session_id, created_at, updated_at FROM builder_sessions ORDER BY updated_at DESC")
	if err != nil {
		fail(w, 500, "查询会话列表失败")
		return
	}
	defer rows.Close()

	var sessions []models.BuilderSession
	for rows.Next() {
		var s models.BuilderSession
		if err := rows.Scan(&s.ID, &s.Title, &s.ProjectName, &s.FinalPrompt, &s.ClaudeSessionID, &s.CreatedAt, &s.UpdatedAt); err != nil {
			continue
		}
		sessions = append(sessions, s)
	}
	if sessions == nil {
		sessions = []models.BuilderSession{}
	}
	success(w, sessions)
}

func CreateBuilderSession(w http.ResponseWriter, r *http.Request) {
	var req struct {
		Title           string `json:"title"`
		ProjectName     string `json:"project_name"`
		FinalPrompt     string `json:"final_prompt"`
		ClaudeSessionID string `json:"claude_session_id"`
		TagOptionIDs    []struct {
			TagID      int64 `json:"tag_id"`
			TagOptionID int64 `json:"tag_option_id"`
		} `json:"tag_option_ids"`
		SnippetIDs []struct {
			SnippetID int64 `json:"snippet_id"`
			SortOrder int   `json:"sort_order"`
		} `json:"snippet_ids"`
		Materials []struct {
			Title    string `json:"title"`
			Content  string `json:"content"`
			SortOrder int   `json:"sort_order"`
		} `json:"materials"`
	}
	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
		fail(w, 400, "请求格式错误")
		return
	}

	var claudeID *string
	if req.ClaudeSessionID != "" {
		claudeID = &req.ClaudeSessionID
	}

	res, err := db.DB.Exec("INSERT INTO builder_sessions (title, project_name, final_prompt, claude_session_id) VALUES (?, ?, ?, ?)",
		req.Title, req.ProjectName, req.FinalPrompt, claudeID)
	if err != nil {
		fail(w, 500, "创建会话失败")
		return
	}

	sessionID, _ := res.LastInsertId()

	// Insert tag associations
	for _, t := range req.TagOptionIDs {
		db.DB.Exec("INSERT INTO builder_session_tags (builder_session_id, tag_id, tag_option_id) VALUES (?, ?, ?)",
			sessionID, t.TagID, t.TagOptionID)
	}

	// Insert snippet associations
	for _, s := range req.SnippetIDs {
		db.DB.Exec("INSERT INTO builder_session_snippets (builder_session_id, snippet_id, sort_order) VALUES (?, ?, ?)",
			sessionID, s.SnippetID, s.SortOrder)
	}

	// Insert materials
	for _, m := range req.Materials {
		db.DB.Exec("INSERT INTO builder_session_materials (builder_session_id, title, content, sort_order) VALUES (?, ?, ?, ?)",
			sessionID, m.Title, m.Content, m.SortOrder)
	}

	success(w, map[string]int64{"id": sessionID})
}

func GetBuilderSession(w http.ResponseWriter, r *http.Request) {
	id, err := strconv.ParseInt(r.PathValue("id"), 10, 64)
	if err != nil {
		fail(w, 400, "无效的 ID")
		return
	}

	var s models.BuilderSession
	err = db.DB.QueryRow("SELECT id, title, project_name, final_prompt, claude_session_id, created_at, updated_at FROM builder_sessions WHERE id=?", id).
		Scan(&s.ID, &s.Title, &s.ProjectName, &s.FinalPrompt, &s.ClaudeSessionID, &s.CreatedAt, &s.UpdatedAt)
	if err != nil {
		fail(w, 404, "会话不存在")
		return
	}

	// Load tags
	tagRows, err := db.DB.Query("SELECT id, builder_session_id, tag_id, tag_option_id FROM builder_session_tags WHERE builder_session_id=?", id)
	if err == nil {
		for tagRows.Next() {
			var t models.SessionTag
			if err := tagRows.Scan(&t.ID, &t.BuilderSessionID, &t.TagID, &t.TagOptionID); err == nil {
				s.Tags = append(s.Tags, t)
			}
		}
		tagRows.Close()
	}

	// Load snippets
	snippetRows, err := db.DB.Query("SELECT id, builder_session_id, snippet_id, sort_order FROM builder_session_snippets WHERE builder_session_id=? ORDER BY sort_order", id)
	if err == nil {
		for snippetRows.Next() {
			var sn models.SessionSnippet
			if err := snippetRows.Scan(&sn.ID, &sn.BuilderSessionID, &sn.SnippetID, &sn.SortOrder); err == nil {
				s.Snippets = append(s.Snippets, sn)
			}
		}
		snippetRows.Close()
	}

	// Load materials
	materialRows, err := db.DB.Query("SELECT id, builder_session_id, title, content, sort_order FROM builder_session_materials WHERE builder_session_id=? ORDER BY sort_order", id)
	if err == nil {
		for materialRows.Next() {
			var m models.SessionMaterial
			if err := materialRows.Scan(&m.ID, &m.BuilderSessionID, &m.Title, &m.Content, &m.SortOrder); err == nil {
				s.Materials = append(s.Materials, m)
			}
		}
		materialRows.Close()
	}

	if s.Tags == nil {
		s.Tags = []models.SessionTag{}
	}
	if s.Snippets == nil {
		s.Snippets = []models.SessionSnippet{}
	}
	if s.Materials == nil {
		s.Materials = []models.SessionMaterial{}
	}

	success(w, s)
}

func UpdateBuilderSession(w http.ResponseWriter, r *http.Request) {
	id, err := strconv.ParseInt(r.PathValue("id"), 10, 64)
	if err != nil {
		fail(w, 400, "无效的 ID")
		return
	}

	var req struct {
		Title           string `json:"title"`
		ProjectName     string `json:"project_name"`
		FinalPrompt     string `json:"final_prompt"`
		ClaudeSessionID string `json:"claude_session_id"`
		TagOptionIDs    []struct {
			TagID      int64 `json:"tag_id"`
			TagOptionID int64 `json:"tag_option_id"`
		} `json:"tag_option_ids"`
		SnippetIDs []struct {
			SnippetID int64 `json:"snippet_id"`
			SortOrder int   `json:"sort_order"`
		} `json:"snippet_ids"`
		Materials []struct {
			Title    string `json:"title"`
			Content  string `json:"content"`
			SortOrder int   `json:"sort_order"`
		} `json:"materials"`
	}
	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
		fail(w, 400, "请求格式错误")
		return
	}

	var claudeID *string
	if req.ClaudeSessionID != "" {
		claudeID = &req.ClaudeSessionID
	}

	_, err = db.DB.Exec("UPDATE builder_sessions SET title=?, project_name=?, final_prompt=?, claude_session_id=? WHERE id=?",
		req.Title, req.ProjectName, req.FinalPrompt, claudeID, id)
	if err != nil {
		fail(w, 500, "更新会话失败")
		return
	}

	// Replace tags
	db.DB.Exec("DELETE FROM builder_session_tags WHERE builder_session_id=?", id)
	for _, t := range req.TagOptionIDs {
		db.DB.Exec("INSERT INTO builder_session_tags (builder_session_id, tag_id, tag_option_id) VALUES (?, ?, ?)",
			id, t.TagID, t.TagOptionID)
	}

	// Replace snippets
	db.DB.Exec("DELETE FROM builder_session_snippets WHERE builder_session_id=?", id)
	for _, s := range req.SnippetIDs {
		db.DB.Exec("INSERT INTO builder_session_snippets (builder_session_id, snippet_id, sort_order) VALUES (?, ?, ?)",
			id, s.SnippetID, s.SortOrder)
	}

	// Replace materials
	db.DB.Exec("DELETE FROM builder_session_materials WHERE builder_session_id=?", id)
	for _, m := range req.Materials {
		db.DB.Exec("INSERT INTO builder_session_materials (builder_session_id, title, content, sort_order) VALUES (?, ?, ?, ?)",
			id, m.Title, m.Content, m.SortOrder)
	}

	success(w, nil)
}

func DeleteBuilderSession(w http.ResponseWriter, r *http.Request) {
	id, err := strconv.ParseInt(r.PathValue("id"), 10, 64)
	if err != nil {
		fail(w, 400, "无效的 ID")
		return
	}

	db.DB.Exec("DELETE FROM builder_session_tags WHERE builder_session_id=?", id)
	db.DB.Exec("DELETE FROM builder_session_snippets WHERE builder_session_id=?", id)
	db.DB.Exec("DELETE FROM builder_session_materials WHERE builder_session_id=?", id)
	db.DB.Exec("DELETE FROM builder_sessions WHERE id=?", id)
	success(w, nil)
}

// AssemblePrompt 组装最终 Prompt
func AssemblePrompt(projectName string, customContent string, tagOptions []models.TagOption, snippets []models.Snippet, suggestions []string, materials []models.SessionMaterial) string {
	var parts []string

	// Project context
	if projectName != "" {
		parts = append(parts, fmt.Sprintf("## 项目上下文\n\n项目名称: %s", projectName))
	}

	// Custom content
	if customContent != "" {
		parts = append(parts, fmt.Sprintf("## 用户输入\n\n%s", customContent))
	}

	// Tag constraints
	if len(tagOptions) > 0 {
		var constraints []string
		for _, opt := range tagOptions {
			constraints = append(constraints, fmt.Sprintf("- %s", opt.ConstraintText))
		}
		parts = append(parts, fmt.Sprintf("## 约束\n\n%s", strings.Join(constraints, "\n")))
	}

	// Snippets
	if len(snippets) > 0 {
		var snippetParts []string
		for _, s := range snippets {
			snippetParts = append(snippetParts, fmt.Sprintf("--- %s ---\n%s", s.Name, s.Content))
		}
		parts = append(parts, fmt.Sprintf("## 参考片段\n\n%s", strings.Join(snippetParts, "\n\n")))
	}

	// Materials
	if len(materials) > 0 {
		var materialParts []string
		for i, m := range materials {
			title := m.Title
			if title == "" {
				title = fmt.Sprintf("参考材料%d", i+1)
			}
			materialParts = append(materialParts, fmt.Sprintf("--- %s ---\n%s", title, m.Content))
		}
		parts = append(parts, fmt.Sprintf("## 参考材料\n\n%s", strings.Join(materialParts, "\n\n")))
	}

	// Suggestions
	if len(suggestions) > 0 {
		parts = append(parts, fmt.Sprintf("## 补充建议\n\n%s", strings.Join(suggestions, "\n")))
	}

	return strings.Join(parts, "\n\n")
}