package lib

import (
	"encoding/json"
	"fmt"
	"strings"
	"time"
)

// Journal entry types
const (
	JournalTypeProtocol    = "protocol"
	JournalTypeHypothesis  = "hypothesis"
	JournalTypeObservation = "observation"
	JournalTypeConnection  = "connection"
	JournalTypeQuestion    = "question"
	JournalTypeReference   = "reference"
)

// Journal status values
const (
	JournalStatusDraft     = 0
	JournalStatusActive    = 1
	JournalStatusResolved  = 2
	JournalStatusDiscarded = 3
)

// JournalData represents the encrypted JSON data stored in entry.Data
type JournalData struct {
	Source          string            `json:"source"`
	ConversationID  string            `json:"conversation_id,omitempty"`
	ConversationURL string            `json:"conversation_url,omitempty"`
	Content         string            `json:"content"`
	RelatedEntries  []string          `json:"related_entries,omitempty"`
	Reasoning       string            `json:"reasoning,omitempty"`
	Metadata        map[string]string `json:"metadata,omitempty"`
}

// CreateJournalInput represents the input for creating a journal entry
type CreateJournalInput struct {
	DossierID      string
	Type           string // protocol, hypothesis, observation, etc.
	Title          string
	Summary        string   // optional - generated if not provided
	Content        string   // full markdown content
	Tags           []string // optional
	Status         int      // optional - defaults to draft
	RelatedEntries []string // optional
	Source         string   // optional - e.g., "opus-4.6"
	Reasoning      string   // optional
	Metadata       map[string]string
}

// JournalSummary represents a journal entry summary for list view
type JournalSummary struct {
	EntryID   string    `json:"entry_id"`
	Type      string    `json:"type"`
	Title     string    `json:"title"`
	Summary   string    `json:"summary"`
	Date      time.Time `json:"date"`
	Status    int       `json:"status"`
	Tags      []string  `json:"tags"`
	DossierID string    `json:"dossier_id,omitempty"`
}

// JournalEntry represents a full journal entry
type JournalEntry struct {
	EntryID        string            `json:"entry_id"`
	DossierID      string            `json:"dossier_id"`
	Type           string            `json:"type"`
	Title          string            `json:"title"`
	Summary        string            `json:"summary"`
	Content        string            `json:"content"`
	Date           time.Time         `json:"date"`
	Status         int               `json:"status"`
	Tags           []string          `json:"tags"`
	RelatedEntries []string          `json:"related_entries,omitempty"`
	Source         string            `json:"source,omitempty"`
	Reasoning      string            `json:"reasoning,omitempty"`
	Metadata       map[string]string `json:"metadata,omitempty"`
}

// GenerateJournalSummary uses Gemini to generate a 1-2 sentence summary
func GenerateJournalSummary(title, journalType, content string) (string, error) {
	prompt := fmt.Sprintf(`Summarize this health journal entry in 1-2 sentences (max 300 chars).
Focus on: what intervention/observation, for what condition, and key details.

Title: %s
Type: %s
Content: %s

Example good summaries:
- "20-25g daily Beluga/Keta targeting phospholipid-DHA → SPM production for aqueduct inflammation."
- "Jan 10 fever may have opened aqueduct drainage. Observing improved tone, eye tracking, head control."
- "Autologous WBC therapy (Utheline/Ricasin/Notokill + ATP) given during active fever."

Respond with ONLY the summary text, no JSON, no extra formatting.`, title, journalType, content)

	// Override default config to return plain text
	plainText := "text/plain"
	maxTokens := 150
	temp := 0.3
	config := &GeminiConfig{
		Temperature:      &temp,
		MaxOutputTokens:  &maxTokens,
		ResponseMimeType: &plainText,
	}

	summary, err := CallGeminiMultimodal([]GeminiPart{{Text: prompt}}, config)
	if err != nil {
		return "", fmt.Errorf("failed to generate summary: %w", err)
	}

	summary = strings.TrimSpace(summary)
	if len(summary) > 300 {
		summary = summary[:297] + "..."
	}

	return summary, nil
}

// CreateJournal creates a new journal entry
func CreateJournal(input CreateJournalInput) (string, error) {
	// Validate required fields
	if input.DossierID == "" {
		return "", fmt.Errorf("dossier_id required")
	}
	if input.Type == "" {
		return "", fmt.Errorf("type required")
	}
	if input.Title == "" {
		return "", fmt.Errorf("title required")
	}
	if input.Content == "" {
		return "", fmt.Errorf("content required")
	}

	// Generate summary if not provided
	if input.Summary == "" {
		var err error
		input.Summary, err = GenerateJournalSummary(input.Title, input.Type, input.Content)
		if err != nil {
			return "", fmt.Errorf("failed to generate summary: %w", err)
		}
	} else {
		// Validate client-provided summary
		if len(input.Summary) > 300 {
			return "", fmt.Errorf("summary too long (max 300 chars)")
		}
	}

	// Build data JSON
	data := JournalData{
		Source:         input.Source,
		Content:        input.Content,
		RelatedEntries: input.RelatedEntries,
		Reasoning:      input.Reasoning,
		Metadata:       input.Metadata,
	}

	dataJSON, err := json.Marshal(data)
	if err != nil {
		return "", fmt.Errorf("failed to marshal data: %w", err)
	}

	// Create entry
	entry := Entry{
		EntryID:   NewID(),
		DossierID: input.DossierID,
		Category:  CategoryNote,
		Type:      input.Type,
		Value:     input.Title,
		Summary:   input.Summary,
		Data:      string(dataJSON),
		Tags:      strings.Join(input.Tags, ","),
		Timestamp: time.Now().Unix(),
		Status:    input.Status, // defaults to 0 (draft) if not set
	}

	if err := dbSave("entries", &entry); err != nil {
		return "", fmt.Errorf("failed to save entry: %w", err)
	}

	return entry.EntryID, nil
}

// GetJournal retrieves a full journal entry
func GetJournal(dossierID, entryID string) (*JournalEntry, error) {
	var entry Entry
	if err := dbLoad("entries", entryID, &entry); err != nil {
		return nil, fmt.Errorf("failed to load entry: %w", err)
	}

	// Verify access
	if entry.DossierID != dossierID {
		return nil, fmt.Errorf("access denied")
	}

	// Verify it's a journal entry
	if entry.Category != CategoryNote {
		return nil, fmt.Errorf("not a journal entry")
	}

	// Parse data JSON
	var data JournalData
	if entry.Data != "" {
		if err := json.Unmarshal([]byte(entry.Data), &data); err != nil {
			return nil, fmt.Errorf("failed to parse data: %w", err)
		}
	}

	// Parse tags
	var tags []string
	if entry.Tags != "" {
		tags = strings.Split(entry.Tags, ",")
	}

	return &JournalEntry{
		EntryID:        entry.EntryID,
		DossierID:      entry.DossierID,
		Type:           entry.Type,
		Title:          entry.Value,
		Summary:        entry.Summary,
		Content:        data.Content,
		Date:           time.Unix(entry.Timestamp, 0),
		Status:         entry.Status,
		Tags:           tags,
		RelatedEntries: data.RelatedEntries,
		Source:         data.Source,
		Reasoning:      data.Reasoning,
		Metadata:       data.Metadata,
	}, nil
}

// ListJournalsInput represents filters for listing journals
type ListJournalsInput struct {
	DossierID string
	Days      int    // filter to last N days (0 = all)
	Status    *int   // filter by status (nil = all)
	Type      string // filter by type (empty = all)
}

// ListJournals retrieves journal summaries with optional filters
func ListJournals(input ListJournalsInput) ([]JournalSummary, error) {
	// Build query
	query := `SELECT entry_id, dossier_id, type, value, summary, tags, timestamp, status
	          FROM entries
	          WHERE dossier_id = ? AND category = ?`
	args := []interface{}{input.DossierID, CategoryNote}

	// Add type filter
	if input.Type != "" {
		query += " AND type = ?"
		args = append(args, input.Type)
	}

	// Add status filter
	if input.Status != nil {
		query += " AND status = ?"
		args = append(args, *input.Status)
	}

	// Add days filter
	if input.Days > 0 {
		cutoff := time.Now().AddDate(0, 0, -input.Days).Unix()
		query += " AND timestamp >= ?"
		args = append(args, cutoff)
	}

	query += " ORDER BY timestamp DESC"

	// Execute query
	var entries []Entry
	if err := dbQuery(query, args, &entries); err != nil {
		return nil, fmt.Errorf("failed to query entries: %w", err)
	}

	// Convert to summaries
	summaries := make([]JournalSummary, len(entries))
	for i, entry := range entries {
		var tags []string
		if entry.Tags != "" {
			tags = strings.Split(entry.Tags, ",")
		}

		summaries[i] = JournalSummary{
			EntryID:   entry.EntryID,
			Type:      entry.Type,
			Title:     entry.Value,
			Summary:   entry.Summary,
			Date:      time.Unix(entry.Timestamp, 0),
			Status:    entry.Status,
			Tags:      tags,
			DossierID: entry.DossierID,
		}
	}

	return summaries, nil
}

// UpdateJournalStatusInput represents input for updating journal status
type UpdateJournalStatusInput struct {
	DossierID  string
	EntryID    string
	Status     *int   // optional: new status
	AppendNote string // optional: append update to content
}

// UpdateJournalStatus updates a journal entry's status or appends a note
func UpdateJournalStatus(input UpdateJournalStatusInput) error {
	// Load entry
	var entry Entry
	if err := dbLoad("entries", input.EntryID, &entry); err != nil {
		return fmt.Errorf("failed to load entry: %w", err)
	}

	// Verify access
	if entry.DossierID != input.DossierID {
		return fmt.Errorf("access denied")
	}

	// Verify it's a journal entry
	if entry.Category != CategoryNote {
		return fmt.Errorf("not a journal entry")
	}

	// Update status if provided
	if input.Status != nil {
		entry.Status = *input.Status
	}

	// Append note if provided
	if input.AppendNote != "" {
		var data JournalData
		if entry.Data != "" {
			if err := json.Unmarshal([]byte(entry.Data), &data); err != nil {
				return fmt.Errorf("failed to parse data: %w", err)
			}
		}

		// Append to content
		timestamp := time.Now().Format("2006-01-02")
		update := fmt.Sprintf("\n\n---\n**Update %s:** %s", timestamp, input.AppendNote)
		data.Content += update

		dataJSON, err := json.Marshal(data)
		if err != nil {
			return fmt.Errorf("failed to marshal data: %w", err)
		}
		entry.Data = string(dataJSON)
	}

	// Save entry
	if err := dbSave("entries", &entry); err != nil {
		return fmt.Errorf("failed to save entry: %w", err)
	}

	return nil
}