package platform

import (
	"database/sql"
	"encoding/json"
	"errors"
	"io"
	"net/http"
	"strings"
)

type Question struct {
	Key      string `json:"key"`
	Required bool   `json:"required"`
}
type OnboardingConfig struct {
	RequireWorkspace bool       `json:"require_workspace"`
	Questions        []Question `json:"questions"`
}

var surveyTypes = map[string]string{
	"team_activity": "string", "job_role": "string", "referral": "string",
	"previous_use": "boolean", "purpose": "string", "company_size": "string",
}

func ParseOnboarding(raw string, callbacks map[string]string) (map[string]OnboardingConfig, error) {
	configs := map[string]OnboardingConfig{}
	if strings.TrimSpace(raw) == "" {
		return configs, nil
	}
	decoder := json.NewDecoder(strings.NewReader(raw))
	decoder.DisallowUnknownFields()
	if err := decoder.Decode(&configs); err != nil {
		return nil, errors.New("invalid FOUNDRY_ONBOARDING JSON")
	}
	if decoder.Decode(new(any)) != io.EOF {
		return nil, errors.New("invalid FOUNDRY_ONBOARDING JSON")
	}
	for project, config := range configs {
		if _, ok := callbacks[project]; !ok {
			return nil, errors.New("onboarding project is not configured")
		}
		seen := map[string]bool{}
		for _, question := range config.Questions {
			if surveyTypes[question.Key] == "" || seen[question.Key] {
				return nil, errors.New("invalid or duplicate onboarding question")
			}
			seen[question.Key] = true
		}
	}
	return configs, nil
}

func validAnswers(config OnboardingConfig, answers map[string]json.RawMessage) bool {
	questions := map[string]Question{}
	for _, question := range config.Questions {
		questions[question.Key] = question
	}
	for key, value := range answers {
		if _, ok := questions[key]; !ok {
			return false
		}
		if surveyTypes[key] == "boolean" {
			var answer *bool
			if json.Unmarshal(value, &answer) != nil || answer == nil {
				return false
			}
		} else {
			var answer *string
			if json.Unmarshal(value, &answer) != nil || answer == nil || len(*answer) > 2000 {
				return false
			}
		}
	}
	for _, question := range config.Questions {
		value, ok := answers[question.Key]
		if question.Required {
			if !ok {
				return false
			}
			if surveyTypes[question.Key] == "string" {
				var answer string
				if json.Unmarshal(value, &answer) != nil || strings.TrimSpace(answer) == "" {
					return false
				}
			}
		}
	}
	return true
}

func (s *service) onboarding(w http.ResponseWriter, r *http.Request, project, account string) error {
	config := s.onboardingConfigs[project]
	if config.Questions == nil {
		config.Questions = []Question{}
	}
	if r.Method == http.MethodGet {
		var answers, result json.RawMessage
		err := s.db.QueryRowContext(r.Context(), "SELECT answers,result FROM onboarding_responses WHERE project=$1 AND account_id=$2", project, account).Scan(&answers, &result)
		if err != nil && !errors.Is(err, sql.ErrNoRows) {
			return err
		}
		reply(w, 200, response{"config": config, "completed": err == nil, "answers": answers, "result": result})
		return nil
	}
	if r.Method != http.MethodPost {
		reject(w, 405, "method_not_allowed")
		return nil
	}
	var input struct {
		Username       *string                    `json:"username"`
		TeamName       string                     `json:"team_name"`
		GenerateInvite bool                       `json:"generate_invite"`
		Answers        map[string]json.RawMessage `json:"answers"`
	}
	if !decode(w, r, &input) {
		return nil
	}
	input.TeamName = strings.TrimSpace(input.TeamName)
	if input.Answers == nil {
		input.Answers = map[string]json.RawMessage{}
	}
	if input.Username != nil {
		value := strings.ToLower(strings.TrimSpace(*input.Username))
		input.Username = &value
		if !usernamePattern.MatchString(value) {
			reject(w, 400, "invalid_username")
			return nil
		}
	}
	if !validAnswers(config, input.Answers) || len(input.TeamName) > 160 || (config.RequireWorkspace && input.TeamName == "") || (input.GenerateInvite && input.TeamName == "") {
		reject(w, 400, "invalid_onboarding")
		return nil
	}
	tx, err := s.db.BeginTx(r.Context(), nil)
	if err != nil {
		return err
	}
	defer tx.Rollback()
	var locked string
	if err = tx.QueryRowContext(r.Context(), "SELECT id::text FROM project_accounts WHERE project=$1 AND id=$2 FOR UPDATE", project, account).Scan(&locked); err != nil {
		return err
	}
	var prior json.RawMessage
	err = tx.QueryRowContext(r.Context(), "SELECT result FROM onboarding_responses WHERE project=$1 AND account_id=$2", project, account).Scan(&prior)
	if err == nil {
		reply(w, 200, response{"completed": true, "result": prior, "already_completed": true})
		return nil
	}
	if !errors.Is(err, sql.ErrNoRows) {
		return err
	}
	if input.Username != nil {
		_, err = tx.ExecContext(r.Context(), "UPDATE project_accounts SET username=$3,updated_at=now() WHERE project=$1 AND id=$2", project, account, *input.Username)
		if err != nil {
			return err
		}
	}
	result := response{}
	var invitation string
	if input.TeamName != "" {
		workspace, err := createWorkspace(r.Context(), tx, project, account, input.TeamName)
		if err != nil {
			return err
		}
		result["workspace_id"] = workspace
		if input.GenerateInvite {
			token, hash := newLinkToken()
			var id string
			err = tx.QueryRowContext(r.Context(), `
INSERT INTO share_links(project,workspace_id,token_hash,role,created_by,expires_at)
VALUES($1,$2,$3,'viewer',$4,now()+interval '7 days') RETURNING id::text
`, project, workspace, hash, account).Scan(&id)
			if err != nil {
				return err
			}
			result["invite_id"] = id
			invitation = s.origin + "/s/" + token
		}
	}
	answers, _ := json.Marshal(input.Answers)
	resultJSON, _ := json.Marshal(result)
	_, err = tx.ExecContext(r.Context(), "INSERT INTO onboarding_responses(project,account_id,answers,result) VALUES($1,$2,$3,$4)", project, account, answers, resultJSON)
	if err != nil {
		return err
	}
	if err = tx.Commit(); err != nil {
		return err
	}
	reply(w, 201, response{"completed": true, "result": result, "invite_url": invitation, "already_completed": false})
	return nil
}